Cell-mediated immunity involves T cells that recognize and eliminate intracellular pathogens. MHC class I presents endogenous antigens to activate CD8+ cytotoxic T cells to kill virally infected cells, while MHC class II presents exogenous antigens to CD4+ helper T cells to upregulate immune functions against bacteria. Humoral immunity involves B cells maturing into plasma cells upon antigen recognition, secreting antibodies, and leaving memory B cells to facilitate a faster response upon reexposure.
Cytokines are low molecular weight polypeptides or glycoproteins that are secreted by cells and have various functions including mediating and regulating immune responses and inflammatory reactions. Cytokines are produced by lymphocytes, monocytes, macrophages, mast cells, glial cells and other cells. They act through autocrine, paracrine or endocrine mechanisms and initiate their actions by binding to specific membrane receptors. Cytokines have pleiotropic, redundant, synergistic and antagonistic effects and form a cytokine network. The major classes of cytokines include interleukins, tumor necrosis factors, interferons, colony stimulating factors, transforming growth factors and chemokines. Cytokines play important roles in various diseases and their therapeutic uses include treatment
introduction of adaptive immunity. classification of adaptive immunity, factor affecting it and mechanism of adaptive immunity comparison between adaptive immunity and innate immunity. characteristic of adaptive immunity . cell mediated immune responses immunoglobulins
types of immunoglobulins. functions of immunoglobulins, hypersensitivity reactions
This document summarizes the key stages in B-lymphocyte maturation, generation, and activation. It discusses how B cells develop from progenitor cells in the bone marrow, where they undergo antigen-independent maturation including immunoglobulin gene rearrangement and positive and negative selection to remove self-reactive cells. Mature B cells then leave the bone marrow equipped with B cell receptors. The document also describes how B cells are activated upon binding of antigen to their receptor, requiring co-stimulation by T helper cells to initiate the antibody response.
Central tolerance refers to deletion of self-reactive T and B cells in the thymus and bone marrow during maturation. T cells that recognize self antigens undergo apoptosis in the thymus. Peripheral tolerance uses backup mechanisms like clonal deletion through activation-induced cell death, clonal anergy from lack of co-stimulation, and suppression by regulatory T cells. These mechanisms help prevent autoimmune disease by silencing self-reactive cells that escape central tolerance.
Lymphocytes continuously recirculate between the vascular system and tissues, which is essential for immune system homeostasis and function. This migration is regulated by cell adhesion molecules and chemokines. Chemokines play a key role in lymphocyte trafficking by facilitating adhesion to and transmigration through vascular endothelium. The process involves lymphocytes first rolling along endothelial cells, then becoming activated and firmly adhering via integrins when they encounter chemokines, and finally transmigrating between endothelial cells into tissues.
cytokines play a key role in controlling the immune system. It facilitate other cells and organs to work, with this presentation you will be able to learn about what are cytokines, their types, & their biological roles along with diseases related to cytokines and cytokines based therapies.
Cell-mediated immunity involves T cells that recognize and eliminate intracellular pathogens. MHC class I presents endogenous antigens to activate CD8+ cytotoxic T cells to kill virally infected cells, while MHC class II presents exogenous antigens to CD4+ helper T cells to upregulate immune functions against bacteria. Humoral immunity involves B cells maturing into plasma cells upon antigen recognition, secreting antibodies, and leaving memory B cells to facilitate a faster response upon reexposure.
Cytokines are low molecular weight polypeptides or glycoproteins that are secreted by cells and have various functions including mediating and regulating immune responses and inflammatory reactions. Cytokines are produced by lymphocytes, monocytes, macrophages, mast cells, glial cells and other cells. They act through autocrine, paracrine or endocrine mechanisms and initiate their actions by binding to specific membrane receptors. Cytokines have pleiotropic, redundant, synergistic and antagonistic effects and form a cytokine network. The major classes of cytokines include interleukins, tumor necrosis factors, interferons, colony stimulating factors, transforming growth factors and chemokines. Cytokines play important roles in various diseases and their therapeutic uses include treatment
introduction of adaptive immunity. classification of adaptive immunity, factor affecting it and mechanism of adaptive immunity comparison between adaptive immunity and innate immunity. characteristic of adaptive immunity . cell mediated immune responses immunoglobulins
types of immunoglobulins. functions of immunoglobulins, hypersensitivity reactions
This document summarizes the key stages in B-lymphocyte maturation, generation, and activation. It discusses how B cells develop from progenitor cells in the bone marrow, where they undergo antigen-independent maturation including immunoglobulin gene rearrangement and positive and negative selection to remove self-reactive cells. Mature B cells then leave the bone marrow equipped with B cell receptors. The document also describes how B cells are activated upon binding of antigen to their receptor, requiring co-stimulation by T helper cells to initiate the antibody response.
Central tolerance refers to deletion of self-reactive T and B cells in the thymus and bone marrow during maturation. T cells that recognize self antigens undergo apoptosis in the thymus. Peripheral tolerance uses backup mechanisms like clonal deletion through activation-induced cell death, clonal anergy from lack of co-stimulation, and suppression by regulatory T cells. These mechanisms help prevent autoimmune disease by silencing self-reactive cells that escape central tolerance.
Lymphocytes continuously recirculate between the vascular system and tissues, which is essential for immune system homeostasis and function. This migration is regulated by cell adhesion molecules and chemokines. Chemokines play a key role in lymphocyte trafficking by facilitating adhesion to and transmigration through vascular endothelium. The process involves lymphocytes first rolling along endothelial cells, then becoming activated and firmly adhering via integrins when they encounter chemokines, and finally transmigrating between endothelial cells into tissues.
cytokines play a key role in controlling the immune system. It facilitate other cells and organs to work, with this presentation you will be able to learn about what are cytokines, their types, & their biological roles along with diseases related to cytokines and cytokines based therapies.
Autoimmunity is the system of immune responses of an organism against its own healthy cells and tissues. Any disease that results from such an aberrant immune response is termed an "autoimmune disease".
Class switching is the process whereby an activated B cell changes its antibody production from IgM to either IgA, IgG, or IgE depending on the functional requirements. By the end of this CAL you should understand: the basic structure and function of an antibody.
The document summarizes the key characteristics and functions of lymphocytes. It describes the three main types of lymphocytes - B lymphocytes, T lymphocytes, and null cells. B lymphocytes mature in bone marrow or bursa of fabricius and produce antibodies, mediating humoral immunity. T lymphocytes mature in the thymus and are responsible for cell-mediated immunity. Null cells have cytotoxic properties and act as intermediates between B and T cells. The document also provides details on T cell subtypes including T helper cells, T suppressor cells, and T cytotoxic cells.
Immunology is the study of the immune system and its functions. The immune system protects the body from infection through innate and adaptive immunity. Innate immunity provides immediate defense against pathogens while adaptive immunity involves immune cells that develop memory to mount stronger responses against specific pathogens. When not functioning properly, the immune system can lead to autoimmune diseases, allergies, and cancer.
The major histocompatibility complex (MHC) is a set of genes that code for cell surface proteins essential for the acquired immune system to recognize foreign molecules in vertebrates. Peptides from intracellular pathogens are carried to the cell surface by MHC class I and MHC class II and presented to CD4 T cells. Antigen presenting cells like dendritic cells, macrophages, and B cells present MHC class II antigens to CD4 T cells, while all nucleated cells present MHC class I antigens.
This document discusses the structure and function of antibodies (immunoglobulins). It notes that antibodies are glycoproteins found in blood and composed mostly of polypeptide chains. The five major classes of antibodies are IgG, IgM, IgA, IgD, and IgE. Each antibody class has a specific structure and plays unique roles in the immune response, such as antigen recognition, complement activation, and providing immunity to newborns. The document focuses on the structures and functions of IgG, IgM, and IgA antibodies. IgG is the most abundant antibody in serum and provides various immune functions. IgM is the first antibody produced during infection and is efficient at complement activation. IgA is mainly found in secret
The document summarizes key aspects of the immune system. It describes how the immune system is made up of cells that develop in primary lymphoid organs like the bone marrow and thymus. Mature cells then travel to secondary lymphoid organs like lymph nodes and spleen. These organs contain various white blood cells that participate in immune responses, developing from hematopoietic stem cells in bone marrow through processes like apoptosis and regulation by genes and cytokines.
Cytokines are proteins that mediate communication between cells to coordinate the immune response. They are secreted by white blood cells and other cells in response to stimuli. Cytokines help regulate immune cell development and function, inducing inflammatory responses, hematopoiesis, cell proliferation and differentiation, and wound healing. They signal through high affinity receptors via autocrine, paracrine, or endocrine actions and exhibit pleiotropy, redundancy, synergy, and antagonism. Cytokines are classified into families including hematopoietins, chemokines, interferons, TNF, and CSFs. TH1 and TH2 cells secrete different cytokine profiles that determine immune response type. Cytokine antagonists and inhibitors regulate cytokine activity.
T CELL ACTIVATION AND IT'S TERMINATIONpremvarma064
T cell activation requires two signals: 1) recognition of antigens displayed on antigen-presenting cells by T cell receptors and 2) co-stimulatory signals through molecules like CD28. This leads T cells to proliferate, differentiate into effector and memory cells, and perform effector functions. Proper activation requires interaction between T cells and antigen-presenting cells in lymphoid tissues, where costimulatory molecules are highly expressed. Dysregulation of T cell activation can lead to autoimmunity or susceptibility to infection.
The document summarizes the immune response to different infectious agents including viruses, bacteria, fungi, parasites. It discusses both the innate and adaptive immune responses targeting each type of pathogen. It also describes mechanisms pathogens use to evade the host immune response, such as antigenic variation, inhibiting phagocytosis, and surface structures that prevent complement activation. Tissue damage during infection can be caused by either the pathogen itself or the host immune response.
The document discusses cytokines, which are proteins that mediate communication between cells of the immune system. It describes the different types of cytokines, including interleukins produced by T-helper cells, lymphokines produced by lymphocytes, and monokines produced by monocytes. The document outlines the roles and functions of specific cytokines like IL-1, IL-2, TNF, IFN-γ and GM-CSF. It also discusses how cytokines are classified based on their structure and roles in innate versus adaptive immunity.
Immune response during bacterial, parasitic and viral infection.pptxVanshikaVarshney5
1) The innate immune response to viruses involves interferon production which stimulates antiviral proteins to block viral replication. Natural killer cells also help destroy infected cells.
2) The adaptive immune response involves humoral immunity with antiviral antibodies that neutralize viruses and prevent infection of cells. Cell-mediated immunity uses cytotoxic T-cells and macrophages to directly kill infected cells.
3) Viruses have evolved mechanisms to evade the immune response, such as reducing MHC expression to avoid detection by T-cells, direct immunosuppression, and antigenic variation for influenza virus.
Immunity involves both specific and non-specific components of the immune system. The non-specific components act as barriers or eliminate a wide range of pathogens, while the specific components adapt to each new disease and generate pathogen-specific immunity. Cell-mediated immunity is mediated by activated macrophages, natural killer cells, cytotoxic T-lymphocytes, and cytokines and does not involve antibodies. It is responsible for phagocytosing and killing intracellular pathogens and virus-infected cells. Memory T cells provide long-term immunity against past infections upon reexposure to the pathogen.
The document summarizes key aspects of the immune system, including its defense mechanisms against pathogens. It describes both nonspecific immunity mechanisms like physical barriers, phagocytosis, inflammation and complement proteins, as well as specific adaptive immunity involving B cells, T cells, antibodies, and memory responses. The immune system protects the body by distinguishing self from non-self and responding to eliminate microbes, viruses, bacteria, fungi and parasites.
Humoral immunity is defined as the immunity mediated by antibodies, which are secreted by B lymphocytes.
B lymphocytes secrete the antibodies into the blood and lymph
This document provides an overview of autoimmunity. It defines autoimmunity as the immune system attacking the body's own tissues, discusses the history of the field and how tolerance normally prevents this, and lists factors that can disrupt tolerance and lead to autoimmune disease. Some key autoimmune diseases are then described, along with criteria for diagnosing autoimmune conditions.
1. Transplantation immunology examines the immune response to transplanted tissues.
2. Major events include the first successful organ transplants in the 1950s-60s of kidneys, livers, hearts, and bone marrow.
3. Graft rejection is driven by an immune response to foreign histocompatibility antigens like MHC proteins, with T-cells playing a key role through cell-mediated responses. Immunosuppressive drugs help prevent rejection by inhibiting T-cell activation and proliferation.
This document provides an introduction to immunology, covering the origin and history of immunology, the functions of the immune system, and some basic concepts. It discusses the organization of the immune system into external defenses like skin and internal defenses including innate immunity and adaptive immunity. It also summarizes the cells and chemicals involved in innate immunity like phagocytes, complement, and cytokines as well as the cells of adaptive immunity like B cells, T cells, and antibodies.
Immunological tolerance is the specific non-reactivity to an antigen due to previous exposure. Tolerance can be induced to self-antigens to prevent autoimmunity or to non-self antigens like donor tissues. Burnet and Medawar discovered that exposure to antigens early in life can induce lifelong tolerance. Tolerance occurs through central tolerance in the thymus during development and peripheral tolerance after lymphocytes leave primary lymphoid organs. Mechanisms of tolerance include clonal deletion, clonal anergy, and receptor editing.
Feiyue Biotechnology as a manufacturer of ELISA kits, Antibodies, Proteins, and related reagents, we aim at providing the best products and related custom service to researchers so that they can have a good starting for their project. High quality has been guaranteed by special technical support.
Autoimmunity is the system of immune responses of an organism against its own healthy cells and tissues. Any disease that results from such an aberrant immune response is termed an "autoimmune disease".
Class switching is the process whereby an activated B cell changes its antibody production from IgM to either IgA, IgG, or IgE depending on the functional requirements. By the end of this CAL you should understand: the basic structure and function of an antibody.
The document summarizes the key characteristics and functions of lymphocytes. It describes the three main types of lymphocytes - B lymphocytes, T lymphocytes, and null cells. B lymphocytes mature in bone marrow or bursa of fabricius and produce antibodies, mediating humoral immunity. T lymphocytes mature in the thymus and are responsible for cell-mediated immunity. Null cells have cytotoxic properties and act as intermediates between B and T cells. The document also provides details on T cell subtypes including T helper cells, T suppressor cells, and T cytotoxic cells.
Immunology is the study of the immune system and its functions. The immune system protects the body from infection through innate and adaptive immunity. Innate immunity provides immediate defense against pathogens while adaptive immunity involves immune cells that develop memory to mount stronger responses against specific pathogens. When not functioning properly, the immune system can lead to autoimmune diseases, allergies, and cancer.
The major histocompatibility complex (MHC) is a set of genes that code for cell surface proteins essential for the acquired immune system to recognize foreign molecules in vertebrates. Peptides from intracellular pathogens are carried to the cell surface by MHC class I and MHC class II and presented to CD4 T cells. Antigen presenting cells like dendritic cells, macrophages, and B cells present MHC class II antigens to CD4 T cells, while all nucleated cells present MHC class I antigens.
This document discusses the structure and function of antibodies (immunoglobulins). It notes that antibodies are glycoproteins found in blood and composed mostly of polypeptide chains. The five major classes of antibodies are IgG, IgM, IgA, IgD, and IgE. Each antibody class has a specific structure and plays unique roles in the immune response, such as antigen recognition, complement activation, and providing immunity to newborns. The document focuses on the structures and functions of IgG, IgM, and IgA antibodies. IgG is the most abundant antibody in serum and provides various immune functions. IgM is the first antibody produced during infection and is efficient at complement activation. IgA is mainly found in secret
The document summarizes key aspects of the immune system. It describes how the immune system is made up of cells that develop in primary lymphoid organs like the bone marrow and thymus. Mature cells then travel to secondary lymphoid organs like lymph nodes and spleen. These organs contain various white blood cells that participate in immune responses, developing from hematopoietic stem cells in bone marrow through processes like apoptosis and regulation by genes and cytokines.
Cytokines are proteins that mediate communication between cells to coordinate the immune response. They are secreted by white blood cells and other cells in response to stimuli. Cytokines help regulate immune cell development and function, inducing inflammatory responses, hematopoiesis, cell proliferation and differentiation, and wound healing. They signal through high affinity receptors via autocrine, paracrine, or endocrine actions and exhibit pleiotropy, redundancy, synergy, and antagonism. Cytokines are classified into families including hematopoietins, chemokines, interferons, TNF, and CSFs. TH1 and TH2 cells secrete different cytokine profiles that determine immune response type. Cytokine antagonists and inhibitors regulate cytokine activity.
T CELL ACTIVATION AND IT'S TERMINATIONpremvarma064
T cell activation requires two signals: 1) recognition of antigens displayed on antigen-presenting cells by T cell receptors and 2) co-stimulatory signals through molecules like CD28. This leads T cells to proliferate, differentiate into effector and memory cells, and perform effector functions. Proper activation requires interaction between T cells and antigen-presenting cells in lymphoid tissues, where costimulatory molecules are highly expressed. Dysregulation of T cell activation can lead to autoimmunity or susceptibility to infection.
The document summarizes the immune response to different infectious agents including viruses, bacteria, fungi, parasites. It discusses both the innate and adaptive immune responses targeting each type of pathogen. It also describes mechanisms pathogens use to evade the host immune response, such as antigenic variation, inhibiting phagocytosis, and surface structures that prevent complement activation. Tissue damage during infection can be caused by either the pathogen itself or the host immune response.
The document discusses cytokines, which are proteins that mediate communication between cells of the immune system. It describes the different types of cytokines, including interleukins produced by T-helper cells, lymphokines produced by lymphocytes, and monokines produced by monocytes. The document outlines the roles and functions of specific cytokines like IL-1, IL-2, TNF, IFN-γ and GM-CSF. It also discusses how cytokines are classified based on their structure and roles in innate versus adaptive immunity.
Immune response during bacterial, parasitic and viral infection.pptxVanshikaVarshney5
1) The innate immune response to viruses involves interferon production which stimulates antiviral proteins to block viral replication. Natural killer cells also help destroy infected cells.
2) The adaptive immune response involves humoral immunity with antiviral antibodies that neutralize viruses and prevent infection of cells. Cell-mediated immunity uses cytotoxic T-cells and macrophages to directly kill infected cells.
3) Viruses have evolved mechanisms to evade the immune response, such as reducing MHC expression to avoid detection by T-cells, direct immunosuppression, and antigenic variation for influenza virus.
Immunity involves both specific and non-specific components of the immune system. The non-specific components act as barriers or eliminate a wide range of pathogens, while the specific components adapt to each new disease and generate pathogen-specific immunity. Cell-mediated immunity is mediated by activated macrophages, natural killer cells, cytotoxic T-lymphocytes, and cytokines and does not involve antibodies. It is responsible for phagocytosing and killing intracellular pathogens and virus-infected cells. Memory T cells provide long-term immunity against past infections upon reexposure to the pathogen.
The document summarizes key aspects of the immune system, including its defense mechanisms against pathogens. It describes both nonspecific immunity mechanisms like physical barriers, phagocytosis, inflammation and complement proteins, as well as specific adaptive immunity involving B cells, T cells, antibodies, and memory responses. The immune system protects the body by distinguishing self from non-self and responding to eliminate microbes, viruses, bacteria, fungi and parasites.
Humoral immunity is defined as the immunity mediated by antibodies, which are secreted by B lymphocytes.
B lymphocytes secrete the antibodies into the blood and lymph
This document provides an overview of autoimmunity. It defines autoimmunity as the immune system attacking the body's own tissues, discusses the history of the field and how tolerance normally prevents this, and lists factors that can disrupt tolerance and lead to autoimmune disease. Some key autoimmune diseases are then described, along with criteria for diagnosing autoimmune conditions.
1. Transplantation immunology examines the immune response to transplanted tissues.
2. Major events include the first successful organ transplants in the 1950s-60s of kidneys, livers, hearts, and bone marrow.
3. Graft rejection is driven by an immune response to foreign histocompatibility antigens like MHC proteins, with T-cells playing a key role through cell-mediated responses. Immunosuppressive drugs help prevent rejection by inhibiting T-cell activation and proliferation.
This document provides an introduction to immunology, covering the origin and history of immunology, the functions of the immune system, and some basic concepts. It discusses the organization of the immune system into external defenses like skin and internal defenses including innate immunity and adaptive immunity. It also summarizes the cells and chemicals involved in innate immunity like phagocytes, complement, and cytokines as well as the cells of adaptive immunity like B cells, T cells, and antibodies.
Immunological tolerance is the specific non-reactivity to an antigen due to previous exposure. Tolerance can be induced to self-antigens to prevent autoimmunity or to non-self antigens like donor tissues. Burnet and Medawar discovered that exposure to antigens early in life can induce lifelong tolerance. Tolerance occurs through central tolerance in the thymus during development and peripheral tolerance after lymphocytes leave primary lymphoid organs. Mechanisms of tolerance include clonal deletion, clonal anergy, and receptor editing.
Feiyue Biotechnology as a manufacturer of ELISA kits, Antibodies, Proteins, and related reagents, we aim at providing the best products and related custom service to researchers so that they can have a good starting for their project. High quality has been guaranteed by special technical support.
interaction of T cells and cytokines of T cell kamilKhan63
This document provides an overview of helper T cells and their role in the immune system. It discusses the different types of helper T cells (TH1, TH2, TH17), the cytokines they produce, and how these cytokines act on other immune cells. The document also outlines the functions of helper T cells, such as activating macrophages, controlling disease, interacting with other immune cells, producing memory T cells, and their role in conditions like COVID-19, HIV, and cancer.
Cytokines are small soluble proteins that are important mediators of the inflammatory response. They are produced by immune cells like lymphocytes and monocytes and act as signaling molecules between cells. The document defines cytokines and provides classifications of cytokines. It describes the roles of key cytokines like IL-1 and IL-2 in innate immunity and leukocyte recruitment during the early immune response. Cytokines function through binding to specific cell surface receptors and activating intracellular signaling pathways.
Cytokines are low molecular weight proteins that are secreted by cells of the immune system and other cells to regulate immune responses. They act as signaling molecules between cells through specific high-affinity receptors. Cytokines control processes like activation, growth, and differentiation of immune cells. They are classified based on their cellular source (monokines, lymphokines) or functional roles (interleukins, interferons, tumor necrosis factors, colony-stimulating factors, chemokines, growth factors). Binding of cytokines to their receptors triggers intracellular signaling cascades that regulate gene expression. Dysregulation of cytokines can contribute to diseases like cytokine release syndrome. Key cytokines discovered at the National Cancer Institute, like interleukin-2, interleukin-
The document discusses cytokines and chemokines. It defines them, classifies them into six families, and describes their general properties and functions. The six families are: interleukin 1, hematopoietin/class 1, interferon/class 2, chemokine, tumor necrosis factor, and interleukin 17 families. Cytokines have pleiotropic, redundant, synergistic, antagonistic, and cascade induction effects. They are important in innate and adaptive immunity.
Cytokines are low molecular weight proteins that are important mediators of the immune system. They can be classified into interleukins, interferons, tumor necrosis factors, colony stimulating factors, chemokines, and growth factors. Cytokines act through specific cell surface receptors and have pleiotropic, redundant, synergistic and antagonistic effects. They are involved in innate immunity, adaptive immunity, inflammation, and hematopoiesis. Therapeutic uses of cytokines include treatment of viral infections, cancer, immunodeficiencies, and autoimmune diseases through administration of cytokines or anti-cytokine antibodies.
Cytokines are small secreted proteins that regulate immunity, inflammation, and cell growth. They are produced by white blood cells and tissue macrophages in response to immune stimuli. The main classes of cytokines include interferons, interleukins, tumor necrosis factors, growth factors, and chemokines. Interferons are produced during viral infections and help limit viral spread. Interleukins are involved in cell communication and direct cell division. Tumor necrosis factors can induce cell death in tumor cells.
Cytokines are proteins that are made by immune and non-immune cells and affect the immune system. There are several types of cytokines including chemokines, colony-stimulating factors, interferons, interleukins, transforming growth factor, and tumor necrosis factor. Cytokines have various properties and activities. They bind to specific receptors on target cells and can have pleiotropic, redundant, synergistic, or antagonistic effects on cellular activities. Cytokines exert autocrine, paracrine, or endocrine actions by binding to receptors on the same, nearby, or distant target cells, respectively.
Cytokines are small secreted proteins that mediate and regulate immunity, inflammation, and hematopoiesis. They are produced in response to an immune stimulus and act as signaling molecules between cells during immune responses. There are several main classes of cytokines, including interleukins, interferons, tumor necrosis factors, growth factors, colony stimulating factors, and chemokines. Cytokines bind to specific cell surface receptors and influence cellular processes like proliferation, differentiation, and activation.
CYTOKINES (Introduction and Description) by Mohammedfaizan ShaikhFaizanShaikh690659
Secreted, low-molecular-weight proteins that
Regulate the nature, intensity and duration of the immune
Response by exerting a variety of effects on lymphocytes and/or
Other cells.
- Cytokines bind to specific receptors on target cells.
- Originally were called lymphokines because they were initially
- Thought to be produced only by lymphocytes. Then monokines
Because they were secreted by monocytes and macrophages.
- Then interleukin because they are produced by some
Leukocytes and affect other leukocytes. The term “cytokine” is
Now used more widely and covers all of the above.
- Don’t forget chemokines, they are also considered cytokines.
Cytokines are small soluble proteins that regulate the immune system's innate and adaptive responses. They are produced in response to stimuli and exert effects through autocrine, paracrine, or endocrine activity. The major cytokine families include tumor necrosis factors, interferons, chemokines, transforming growth factors, colony-stimulating factors, and interleukins. Cytokines play key roles in both innate immunity, through recruitment of effector cells, and adaptive immunity, by influencing T helper cell differentiation.
Cytokines are proteins that are made by immune and non-immune cells and affect the immune system. There are several types of cytokines, including chemokines, colony-stimulating factors, interferons, interleukins, transforming growth factor, and tumor necrosis factor. Cytokines have various properties, such as binding to specific receptors on target cells, exhibiting pleiotropy by having different effects on different cells, demonstrating redundancy by having similar functions, and synergism by having combined effects greater than individual effects. Cytokines can act through autocrine, paracrine, or endocrine mechanisms.
CYTOKINES
NOMENCLATURE OF CYTOKINES
PROPERTIES OF CYTOKINES
CYTOKINES BELONG TO FOUR FAMILIES
CYTOKINES RECEPTORS
CLASS I AND CLASS II CYTOKINE RECEPTORS
ACTIVATION OF SIGNAL TRANSDUCTION PATHWAY BY CYTOKINE
1.Immunoglobulin superfamily receptors
2. Class I cytokine receptor family (also known as hematopoietin receptors family)
Three subfamilies of the class I cytokine receptor family (hematopoietin)
3. Class II cytokine receptor family (also known as Interferon receptors family)
4. TNF receptor superfamily
5. Chemokine receptors
Functional Categories of Cytokines
A. Mediators of natural immunity
B.Cytokines acting as mediators and regulators of adaptive immunity
C. Cytokines acting as stimulators of haematopoiesis
Cytokine Antagonists
IMMUNE REGULATION
A. Regulation by cytokines
B. Regulation by regulatory T cells (Tregs)
Cytokine cross-regulation
Therapeutic Uses of Cytokines and their Receptors
Cytokines are cell signaling molecules that aid cell-to-cell communication in the immune system. They are proteins, peptides, or glycoproteins secreted by immune cells that mediate and regulate immunity, inflammation, and hematopoiesis. Cytokines bind to specific receptors on target cells and regulate the immune response by stimulating or inhibiting cell activation, proliferation, and differentiation. Abnormal cytokine production or receptor expression has been implicated in diseases like septic shock, toxic shock syndrome, and cancer.
Cytokines are cell signaling molecules that aid cell-to-cell communication and stimulate cell movement. They are produced by immune cells and mediate processes like immunity, inflammation, and blood cell production. Cytokines bind to receptors on target cells and alter gene expression through signal transduction pathways. They exhibit properties like redundancy, synergy, and antagonism that allow for coordinated regulation of cellular activity. Diseases have been linked to overproduction or underproduction of cytokines, such as septic shock resulting from excessive cytokine levels during bacterial infection.
This document discusses cytokines, which are low molecular weight proteins that mediate communication between cells of the immune system. Cytokines are secreted by white blood cells and other cells to regulate immune responses. They belong to four main families and signal to target cells by binding specific receptors. Cytokines play roles in processes like immune cell development, inflammation, hematopoiesis, and wound healing. Their effects are targeted through selective receptor expression and localized secretion between interacting cells.
This document discusses cytokines, specifically interferons and interleukins. It provides definitions and classifications of interferons, including three main types - alpha, beta, and gamma. Interferons are proteins that help fight viral infections and regulate the immune system. The document also defines interleukins as proteins that mediate communication between cells, regulating cell growth and immune responses. It describes two major interleukin families - interleukin-1 and interleukin-2 families - and provides examples of interleukins in each.
Cytokines are low molecular weight proteins secreted by immune cells that mediate communication between cells. They include interleukins, interferons, tumor necrosis factors, chemokines, and others. Cytokines act through autocrine, paracrine, or endocrine mechanisms. They have pleiotropic, redundant, synergistic, and antagonistic effects and induce cascades of other cytokines. Cytokines mediate innate and adaptive immunity through effects on cell activation, proliferation, differentiation, and recruitment. Chemokines are a subfamily of cytokines that direct cell migration through interaction with specific chemokine receptors on target cells.
This ppt covers:
Central dogma, discoverer of central dogma, Reason why its called central dogma, DNA, RNA, Protein, functions of protein, Types of RNA, DNA replication, Protein synthesis, Transcription, Translation, Exceptions of central dogma, Reverse transcription , prions, genetic code, mutation with types and causes
Disease states associated with fat soluble vitaminsMaliha Firdous
This document discusses diseases associated with fat-soluble vitamins. It covers night blindness and xerophthalmia associated with vitamin A deficiency, which can damage the eyes. Rickets, caused by vitamin D deficiency, results in weak and soft bones. Osteoporosis is discussed as being linked to vitamin D levels as well. Vitamin E deficiency can cause hemolytic anemia, where red blood cells are destroyed faster than they can be replaced. The document also covers vitamin K deficiency bleeding in newborns.
From this ppt you can gather information about cytokine, How they are produced, how they work, what are their types , properties and functions, How they act and what their therapeutic uses are. references are also given in case you want more information about cytokines.
In this ppt I've discussed what vitamin d is and its forms as well as structural difference between two amin forms of vitamin d. Function and dietary requirement is also included in this ppt along with metabolism
Esters can undergo several chemical reactions including hydrolysis, ammonolysis, reduction, and reactions with Grignard reagents. One reaction is trans esterification where an ester is reacted with an alcohol to form a new ester and alcohol byproduct.
Vitamin D
forms of vitamin D
difference between vitamin D2 and vitamin D3
Metabolism of vitamin D
Dietary requirement of vitamin D
Functions of vitamin D
Symptoms of vitamin D deficiency
This document discusses acids and bases. It defines acids and bases according to Arrhenius, Bronsted-Lowry, and Lewis theories. It explains the properties of acids and bases, including neutralization reactions between acids and bases that produce salts and water. Examples of strong vs. weak acids and bases are given. The document also discusses hard and soft acids and bases according to the hard and soft acid and base theory. Common uses of bases like sodium hydroxide and ammonium hydroxide are listed.
This ppt is about amazon alexa .
In it you can easily learn about alexa, its capabilities, abou Amazon echo and echo dot.how much alexa is used and what it can do.
Social media refers to websites and applications that allow users to share content and communicate. Facebook has the most users worldwide, with over 1.5 billion. Social media is widely used, with over half of the global population being active on mobile social platforms. It is used for various purposes like staying connected with others, sharing ideas and reviews, and raising awareness for causes. While it has benefits like education and connectivity, it also has some negative effects like addiction, privacy issues, and cyberbullying.
Carbohydrates are classified as monosaccharides, oligosaccharides, or polysaccharides depending on their size. Monosaccharides are the simplest and include trioses, tetroses, pentoses, and hexoses. Oligosaccharides contain a few monosaccharide units and include disaccharides like sucrose. Polysaccharides are long chains and include homopolysaccharides like starch and glycogen for storage, and structural heteropolysaccharides like cellulose and chitin. Carbohydrates provide energy, structural support, storage, sweetness, and are a source of B-vitamins. They can be dextrorotatory, levorotatory, or exist as anomers that differ at carbon 1
This slide contains all information you need on Microbiology of water and wastewater. Methods of water purification and water borne diseases have also been discussed in this slide
This document provides an overview of Gilgit Baltistan, a northern region of Pakistan. It discusses Gilgit Baltistan's geography, including its many mountain peaks over 7,000 meters high. It also describes Gilgit Baltistan's culture, including traditional musical instruments, dances featuring long robes and swords, and foods like breads and curries. Additionally, it notes the region's historical places, languages including Shina and Wakhi, and religious and cultural festivals.
Waste water treatment removes contaminants from household and industrial wastewater through a multi-step municipal treatment process including primary, secondary, and advanced treatments before final disposal. Inadequate treatment increases health risks and endangers ecosystems by spreading disease, killing aquatic life, and accumulating toxins, while proper treatment reduces risks, generates electricity, and supports agriculture. Common disposal methods include natural processes like dilution and land treatment, or artificial ones like surface water discharge or reuse.
Black holes are regions of space where gravity is so strong that nothing, not even light, can escape. They can form when large stars collapse at the end of their life cycles, compressing their mass into a tiny space. Black holes warp spacetime so severely that they can pull objects inward and may potentially serve as portals to other universes or allow for time travel according to some theories. Scientists study black holes by observing the effects of their strong gravitational forces, such as emitting x-rays and warping of light.
Soil microbiology is the study of microorganisms that exist in soil, including bacteria like Pseudomonas aeruginosa and Nitrobacter, fungi such as Pythium and Verticillium, algae, actinomycetes, nematodes, protozoa, and amoebas. Soil microbes play important roles like breaking down organic matter, fixing nitrogen, recycling nutrients, promoting plant growth, and controlling pests and diseases, though some can also cause plant diseases, compete with crops, and deplete oxygen from soil.
This 3-sentence document discusses safety topics by Maliha Firdous including protection, avoiding accidents, and fire radiation. The document suggests being cautious of potential dangers and taking necessary precautions. Overall, it seems to promote safety awareness.
Food preservation uses physical or chemical agents to prevent microbial spoilage of food by employing either the inhibition principle or killing principle. The inhibition principle reduces pH, uses preservatives, or low temperatures to inhibit microbial growth, while the killing principle uses heat treatment, irradiation, gases, or pasteurization to kill microorganisms. Food preservation has advantages like preventing spoilage, increasing safe storage periods, and making out of season foods available.
ESR spectroscopy in liquid food and beverages.pptxPRIYANKA PATEL
With increasing population, people need to rely on packaged food stuffs. Packaging of food materials requires the preservation of food. There are various methods for the treatment of food to preserve them and irradiation treatment of food is one of them. It is the most common and the most harmless method for the food preservation as it does not alter the necessary micronutrients of food materials. Although irradiated food doesn’t cause any harm to the human health but still the quality assessment of food is required to provide consumers with necessary information about the food. ESR spectroscopy is the most sophisticated way to investigate the quality of the food and the free radicals induced during the processing of the food. ESR spin trapping technique is useful for the detection of highly unstable radicals in the food. The antioxidant capability of liquid food and beverages in mainly performed by spin trapping technique.
Current Ms word generated power point presentation covers major details about the micronuclei test. It's significance and assays to conduct it. It is used to detect the micronuclei formation inside the cells of nearly every multicellular organism. It's formation takes place during chromosomal sepration at metaphase.
This presentation explores a brief idea about the structural and functional attributes of nucleotides, the structure and function of genetic materials along with the impact of UV rays and pH upon them.
Comparing Evolved Extractive Text Summary Scores of Bidirectional Encoder Rep...University of Maribor
Slides from:
11th International Conference on Electrical, Electronics and Computer Engineering (IcETRAN), Niš, 3-6 June 2024
Track: Artificial Intelligence
https://www.etran.rs/2024/en/home-english/
The debris of the ‘last major merger’ is dynamically youngSérgio Sacani
The Milky Way’s (MW) inner stellar halo contains an [Fe/H]-rich component with highly eccentric orbits, often referred to as the
‘last major merger.’ Hypotheses for the origin of this component include Gaia-Sausage/Enceladus (GSE), where the progenitor
collided with the MW proto-disc 8–11 Gyr ago, and the Virgo Radial Merger (VRM), where the progenitor collided with the
MW disc within the last 3 Gyr. These two scenarios make different predictions about observable structure in local phase space,
because the morphology of debris depends on how long it has had to phase mix. The recently identified phase-space folds in Gaia
DR3 have positive caustic velocities, making them fundamentally different than the phase-mixed chevrons found in simulations
at late times. Roughly 20 per cent of the stars in the prograde local stellar halo are associated with the observed caustics. Based
on a simple phase-mixing model, the observed number of caustics are consistent with a merger that occurred 1–2 Gyr ago.
We also compare the observed phase-space distribution to FIRE-2 Latte simulations of GSE-like mergers, using a quantitative
measurement of phase mixing (2D causticality). The observed local phase-space distribution best matches the simulated data
1–2 Gyr after collision, and certainly not later than 3 Gyr. This is further evidence that the progenitor of the ‘last major merger’
did not collide with the MW proto-disc at early times, as is thought for the GSE, but instead collided with the MW disc within
the last few Gyr, consistent with the body of work surrounding the VRM.
When I was asked to give a companion lecture in support of ‘The Philosophy of Science’ (https://shorturl.at/4pUXz) I decided not to walk through the detail of the many methodologies in order of use. Instead, I chose to employ a long standing, and ongoing, scientific development as an exemplar. And so, I chose the ever evolving story of Thermodynamics as a scientific investigation at its best.
Conducted over a period of >200 years, Thermodynamics R&D, and application, benefitted from the highest levels of professionalism, collaboration, and technical thoroughness. New layers of application, methodology, and practice were made possible by the progressive advance of technology. In turn, this has seen measurement and modelling accuracy continually improved at a micro and macro level.
Perhaps most importantly, Thermodynamics rapidly became a primary tool in the advance of applied science/engineering/technology, spanning micro-tech, to aerospace and cosmology. I can think of no better a story to illustrate the breadth of scientific methodologies and applications at their best.
EWOCS-I: The catalog of X-ray sources in Westerlund 1 from the Extended Weste...Sérgio Sacani
Context. With a mass exceeding several 104 M⊙ and a rich and dense population of massive stars, supermassive young star clusters
represent the most massive star-forming environment that is dominated by the feedback from massive stars and gravitational interactions
among stars.
Aims. In this paper we present the Extended Westerlund 1 and 2 Open Clusters Survey (EWOCS) project, which aims to investigate
the influence of the starburst environment on the formation of stars and planets, and on the evolution of both low and high mass stars.
The primary targets of this project are Westerlund 1 and 2, the closest supermassive star clusters to the Sun.
Methods. The project is based primarily on recent observations conducted with the Chandra and JWST observatories. Specifically,
the Chandra survey of Westerlund 1 consists of 36 new ACIS-I observations, nearly co-pointed, for a total exposure time of 1 Msec.
Additionally, we included 8 archival Chandra/ACIS-S observations. This paper presents the resulting catalog of X-ray sources within
and around Westerlund 1. Sources were detected by combining various existing methods, and photon extraction and source validation
were carried out using the ACIS-Extract software.
Results. The EWOCS X-ray catalog comprises 5963 validated sources out of the 9420 initially provided to ACIS-Extract, reaching a
photon flux threshold of approximately 2 × 10−8 photons cm−2
s
−1
. The X-ray sources exhibit a highly concentrated spatial distribution,
with 1075 sources located within the central 1 arcmin. We have successfully detected X-ray emissions from 126 out of the 166 known
massive stars of the cluster, and we have collected over 71 000 photons from the magnetar CXO J164710.20-455217.
ANAMOLOUS SECONDARY GROWTH IN DICOT ROOTS.pptxRASHMI M G
Abnormal or anomalous secondary growth in plants. It defines secondary growth as an increase in plant girth due to vascular cambium or cork cambium. Anomalous secondary growth does not follow the normal pattern of a single vascular cambium producing xylem internally and phloem externally.
What is greenhouse gasses and how many gasses are there to affect the Earth.moosaasad1975
What are greenhouse gasses how they affect the earth and its environment what is the future of the environment and earth how the weather and the climate effects.
hematic appreciation test is a psychological assessment tool used to measure an individual's appreciation and understanding of specific themes or topics. This test helps to evaluate an individual's ability to connect different ideas and concepts within a given theme, as well as their overall comprehension and interpretation skills. The results of the test can provide valuable insights into an individual's cognitive abilities, creativity, and critical thinking skills
Unlocking the mysteries of reproduction: Exploring fecundity and gonadosomati...AbdullaAlAsif1
The pygmy halfbeak Dermogenys colletei, is known for its viviparous nature, this presents an intriguing case of relatively low fecundity, raising questions about potential compensatory reproductive strategies employed by this species. Our study delves into the examination of fecundity and the Gonadosomatic Index (GSI) in the Pygmy Halfbeak, D. colletei (Meisner, 2001), an intriguing viviparous fish indigenous to Sarawak, Borneo. We hypothesize that the Pygmy halfbeak, D. colletei, may exhibit unique reproductive adaptations to offset its low fecundity, thus enhancing its survival and fitness. To address this, we conducted a comprehensive study utilizing 28 mature female specimens of D. colletei, carefully measuring fecundity and GSI to shed light on the reproductive adaptations of this species. Our findings reveal that D. colletei indeed exhibits low fecundity, with a mean of 16.76 ± 2.01, and a mean GSI of 12.83 ± 1.27, providing crucial insights into the reproductive mechanisms at play in this species. These results underscore the existence of unique reproductive strategies in D. colletei, enabling its adaptation and persistence in Borneo's diverse aquatic ecosystems, and call for further ecological research to elucidate these mechanisms. This study lends to a better understanding of viviparous fish in Borneo and contributes to the broader field of aquatic ecology, enhancing our knowledge of species adaptations to unique ecological challenges.
The use of Nauplii and metanauplii artemia in aquaculture (brine shrimp).pptxMAGOTI ERNEST
Although Artemia has been known to man for centuries, its use as a food for the culture of larval organisms apparently began only in the 1930s, when several investigators found that it made an excellent food for newly hatched fish larvae (Litvinenko et al., 2023). As aquaculture developed in the 1960s and ‘70s, the use of Artemia also became more widespread, due both to its convenience and to its nutritional value for larval organisms (Arenas-Pardo et al., 2024). The fact that Artemia dormant cysts can be stored for long periods in cans, and then used as an off-the-shelf food requiring only 24 h of incubation makes them the most convenient, least labor-intensive, live food available for aquaculture (Sorgeloos & Roubach, 2021). The nutritional value of Artemia, especially for marine organisms, is not constant, but varies both geographically and temporally. During the last decade, however, both the causes of Artemia nutritional variability and methods to improve poorquality Artemia have been identified (Loufi et al., 2024).
Brine shrimp (Artemia spp.) are used in marine aquaculture worldwide. Annually, more than 2,000 metric tons of dry cysts are used for cultivation of fish, crustacean, and shellfish larva. Brine shrimp are important to aquaculture because newly hatched brine shrimp nauplii (larvae) provide a food source for many fish fry (Mozanzadeh et al., 2021). Culture and harvesting of brine shrimp eggs represents another aspect of the aquaculture industry. Nauplii and metanauplii of Artemia, commonly known as brine shrimp, play a crucial role in aquaculture due to their nutritional value and suitability as live feed for many aquatic species, particularly in larval stages (Sorgeloos & Roubach, 2021).
2. BY: MALIHA FIRDOUS
Table of Contents
1.Cytokines
2.Production of cytokines
3.Working of cytokines
4.Properties of cytokines
5.Resemblance to hormones
6.Nomenclature of cytokines
7.Types of Actions cytokines perform
8.Types of cytokine
9.Receptors on cytokines
10. Bio-Functions of cytokines
11. Therapeutic uses of cytokines
12. References
3. CYTOKINES
Cytokines is the general term for a large group of molecules involved in signaling
between cells during immune responses.
Cytokines or immune-cytokines
were initially used to separate the
immune-modulatory proteins, also
called immune-transmitters, from
other growth factors that modulate
proliferation and bioactivities of
non-immune cells.
Cytokines are basically a diverse group of non antibody, low molecular weight,
small, soluble, secreted proteins that are produced in response to an antigen and
function as chemical messengers for regulating the innate and adaptive immune
systems.
4. PRODUCTION OF CYTOKINES
Cytokines are produced by virtually all cells
involved in both natural and specific immunity
innate and adaptive immunity, but especially they
are produced by T- helper lymphocytes. They are
synthesized and released by WBC’s and tissue
macrophages. The activation of cytokine-
producing cells triggers them to synthesize and
secrete their cytokines. They are produced during immune and inflammatory
responses and secretion of these mediators is transient and closely regulated.
WORKINGOF CYTOKINES
Cytokines are released by cytokine
producing cells either into the blood
circulation or directly into tissues as
they get a stimulus of the presence of
target cell. These cytokines locate
target cells and interact with receptors
on the target cells by binding to them.
This interaction triggers or stimulated
specific responses by the target cells.
PROPERTIES OF
CYTOKINES
1) Cytokines are small secreted proteins
which mediate and regulate immunity,
5. inflammation, and hematopoiesis.
2) They generally (although not always) act over short distances and short time
spans and at very low concentration.
3) They are pleiotropic means that a particular cytokine can act on a number of
different type of cells rather than a single type.
4) They are redundant means that they have the ability that a number of
different cytokines can carry out same functions.
5) They are multifunctional means that the same cytokine can regulate a
number of different functions.
6) Some of the cytokines are antagonistic in the way that one cytokine
stimulates a particular function whereas another cytokine inhibits that same
function.
7) Some are synergistic where in two different cytokines have greater effects in
combination than either of the two would by themselves.
8) The affinity between cytokines ad their receptor is very high. Because of
high affinity, cytokines can mediate biological effects at Pico-molar
concentration.
RESEMBLANCE TO HORMONES
Cytokines resemble hormones in their biological activity & systemic level, for
example, inflammation, systemic inflammatory responsesyndrome, acutephase
reaction, wound healing, and the neuroimmune network.
Cytokines act on a wider spectrumof target cells than hormones. The major
feature distinguishing cytokines fromhormones is the fact that cytokines are not
produced by specialized cells organized in specialized glands. Cytokines area
secreted protein which means that their expression site does not predict where
they exert their biological function. Several cytokines primary structure was found
to be identical with enzymes. Cytokines do not possessenzymatic activities
although there is a growing list of exceptions. Other cytokines require proteolytic
activation.
NOMENCLATURE OF CYTOKINES
6. Cytokines have been classified on the basis of their presumed function, cell of
secretion or their target of action because cytokines are characterized by
considerable redundancy and pleiotropism.
Interleukin was previously used for those cytokines whose presumed targets
are white blood cells (leukocytes). It is now used for designation of newer
cytokine molecules and bears little relation to their presumed function. The
majority of these cytokines are produced by T-helper cells.
Lymphokines: They are produced by activated T-cells, primarily bt T-helper
lymphocytes.
Monokines:They are produced exclusively by mononuclear phagocytes or
monocytes.
Interferon: They are involved in antiviral responses.
Colony stimulating factors:They supportthe growth of cells in semisolid
media.
Chemokines: They mediate chemo-attraction (chemo taxis) between cells.
They are those cytokines which have chemo-tactic activities i.e. are related with
chemical based activities.
ACTIONS OF CYTOKINES
• AUTOCRINE:
In it cytokine binds to receptoron the same
cell that had secreted it that means its target
cell is that same cell from which it had been
secreted.
• PARACRINE:
In it cytokine binds to receptors on nearby cells.
• ENDOCRINE:
In it cytokine binds to receptors on cells
present in distant parts of the body by
moving through blood circulation.
7. TYPES OF CYTOKINES
INTERLEUKINS:
Produced by suchleukocytes as lymphocytes and monocytes, interleukins are
glycol-proteins involved in the activation and differentiation of immune cells. They
also play an important role in the proliferation, migration, maturation, pro- and
anti-inflammatory activities, as well as adhesion of these cells.
Together with interleukin receptors, interleukins belong to a super family (IL super
family) that is made up of proteins. While it's easy to generalize the functions of
these cytokines, this is largely dependent on the type of interleukins. Currently,
over 43 members of this super family have been identified (IL-1 to IL-43).
Like some of the other cytokines, interleukins are made up of proteins. Typically,
this is in responseto invading pathogens/antigens. While high volumes may be
produced depending on the type of interleukins and the invading organism, a small
quantity of the molecule is required to activate biological effects.
While a good number of interleukins elicit an action on the same cells that
produced them, some can enter the bloodstream which allows them to be
transported and elicit biological effects on distant cells in the body. For instance,
while IL-2 elicits biological effects on T cells (which produced them), IL-1 can
enter the bloodstream and reach the central nervous system.
Some of the other properties of interleukins include:
Synthesis is a self-limited process
Stimulate up-regulatory and down-regulatory mechanisms
Have redundant functions in the body - Given interleukins can cause
different effects on various types of cells
Can influence the synthesis and functioning of other interleukins
As already mentioned, different types of interleukins have different
functions. The following are some of the functions of a few of these
molecules:
· IL-1 - Indirectly stimulates immune responses via various effector proteins and
other cytokines.
8. · IL- 2- Interleukin 2 plays an important role in growth regulation of T cells.
· IL-3 - Stimulates the production of myeloid progenitor cells by
hematopoietic stem cells. However, an interaction between IL-3 and IL-7 results in
the production of lymphoid progenitor cells from hematopoietic stem cells.
· IL-4 - Interleukin 4 is involved in a number of biological processes ranging
from the proliferation of T cells and B cell stimulation to humoral and adaptive
immunity. Moreover, it contributes to the production of a number of cells
including dendritic cells, Th1 cells as well as Interferon Gamma cells.
· IL-5 - Like Il-4 and IL-13, interleukin 5 is also involved in stimulating the
growth of B-cells. However, it is also involved in increased secretion of
immunoglobin as well as activation of eosinophils.
· IL-6 - In addition to being the primary mediator in such illnesses as fever,
interleukin 6 has also been shown to overcome the blood-brain barrier in activating
the expression of Prostaglandin E2 in the hypothalamus which results in body
temperature change.
Some of the other common interleukins include:
IL-8 - involved in the induction of chemo taxis
IL-10 - involved in inflammation as well as regulation of the immune
responses
IL-18 - involved in both immune responses in the body(innate and adaptive
responses)
IL-33 - involved in immune responses of Th2 (e.g. parasitic infections)
INTERFERONS (IFNS)
Interferon is a family consisting of widely expressed signaling proteins. Like the
other cytokines, interferons are also released by cells of the host's immune system
in responseto such invading organisms as bacteria and viruses.
They are also released to respond to tumor cells in some organisms. Currently,
three types of interferons have been identified. These include Type I IFNs, Type II
IFN, and Type III IFNs.
Type I IFNs (Type I Interferons)
9. Type I interferons are divided into two major groups that include IFN-α and IFN-β
as well as a number of additional isotopes that include, among others, IFN-κ, IFN-
ω, and IFN-δ. While only one type of IFN-β exists, IFN-α is further divided into
several subtypes including IFN-α1, IFN-α2, IFN-α3, IFN-α4, IFN-α5, and IFN-α6
among others.
In the body, the productionof Type I IFNs is dependent on the presence of
various microorganisms. For instance, following a viral infection, a signaling
pathway that causes phosphorylation, dimerization as well as passage of the
interferon responsefactor 3 (IRF3) to the nucleus is activated.
Along with a number of other transcription factors, IRF3 activates that synthesis of
IFN-β gene that binds to the interferon receptors located on the surface of an
infected cell which ultimately results in interferon response.
Through these responses, interferons help in the recruitment of effector molecules
that protectthe cells against infections (bacterial and viral infections). For instance,
by activating the production of natural killer cells and macrophages, interferons
contribute to the destruction of both the viruses and infected cells.
* Cells responsible for the productionof IFN-α and IFN-β are collectively known
as interferon-producing cells (IPCs) or natural interferon-producing cells.
IFN productionmay be presented as follows:
Functions of Type I interferons (IFN-α and IFN-β) are generally divided into three
main categories that include:
· Influence resistance to viral replication in cells - This is achieved through the
destruction of viral mRNA required for viral replication as well as inhibiting the
translation of viral proteins.
· Promote Ligand increase - Type I interferons promote an increase in ligands to
the receptors of NK cells which in turn stimulates them to attack and lyses infected
cells.
· Activate the destruction of infected cells by NK cells and macrophages.
* Given that Type 1 interferons also plan a role in immunosuppressive activities,
they are also used for the purposes oftreating autoimmune diseases.
Type II Interferon
10. Type II interferon is made up of a single cytokine known as IFN-y. This cytokine
is largely produced byTHI T cells, activated Natural Killer cells as well as CD8+
T cells. Unlike cytokines of Type I interferons, the gene responsible for encoding
the Type II cytokine is located in chromosome12 in human beings.
Moreover, IFN-y has been shown to be different from the other interferons in that
it does not producea potent antiviral effect. Rather, it largely serves to activate
effector cells.
While it's produced byT cells in adaptive immunity (following an increase in
antigen), IFN-y is produced bynatural killer cells in the innate immune system and
acts as a mediator. In the adaptive immune system, increased productionof IFN-y
is promoted by IL-12 and IL-18.
On the other hand, IL-4 and IL-10 correspond to the negative regulators involved
in its production. Apart from T cells, B cells and professional antigen-presenting
cells have also been shown to play a role in the production of IFN-y.
Like cytokines of Type I interferons, IFN-y also contributes to cell responseto
viral infections. Forinstance, by activating and causing the induction of MHC
(major histocompatibility complex), IFN-y has been shown to play a role in long-
term controlof viral infections in cells. In the process, it also coordinates the
transition from innate to adaptive immunity.
Some of the other functions of IFN-y include:
· Macrophage activation - By promoting the activation of macrophages, IFN-y
contributes to phagocytic and pinocytic activities of these cells and thus contributes
to microbial destruction.
· Inhibiting cell growth - In the body, IFN-y has also been shown to inhibit cell
growth and thus promote apoptosis.
Type III interferons
Unlike Type II interferon that only consists of a single cytokine, Type III is divided
into three important cytokines that include IFN-λ1, IFN-λ2, and IFN-λ3. Also
known as IL-28 (a & b) and IL-29, Type III interferons are characterized by a
structure that is more similar to proteins of the family IL-10.
On the other hand, the signaling pathway of these cytokines has been shown to
resemble that of Type I interferons in that they are dependent on the actions of
IRFs and NF-kB. While these cytokines also regulate a number of similar functions
as Type I interferons, they primarily function in mucosal epithelial cells (as well as
11. liver cells in human beings) where they serve to protectthem from viral infections.
CHEMOKINES
Chemokines are a type of protein cytokine that play an important role in chemo
taxis. As such, there may be signals that guide certain immune cells to the affected
site.
Currently, about 50 Chemokines have been identified. They are divided into four
families based on the location of N-terminal cysteine residues in their three-
dimensional structure.
These include:
CC Chemokines - CC Chemokines are characterized by two adjacent cysteine
(known as CC chemokine ligands) located near the N-terminus of the structure. Of
the 27 CC Chemokines (CCL-1 to CCL-28) that have been identified so far, only 6
have 6 cysteine while the rest are characterized by four of these molecules.
For the most part, CC Chemokines are chemo tactic for monocytes with a few
being chemo tactic for lymphocytes. As such, they promote the
movement/migration of these cells to the affected site.
CXC Chemokines - As compared to CC chemokine, CXC Chemokines are
generally characterized by two cysteine located at the N-terminus. Here, the
cysteine is separated by an amino acid. So far, seventeen of these cytokines have
been identified. They are chemo tactic for neutrophils and thus promote the
movement/migration of these cells to the affected site.
CXCL8 (also known as IL-8) is one of the most common CXC Chemokines. It is
responsible for the recruitment of neutrophils as well as maintaining inflammatory
reactions.
With regards to neutrophils recruitment, CXC Chemokines have to interact with
the appropriate receptors located on the surface of neutrophils. For instance, by
interacting with CXCRI and CXCR2 receptors located on the surface of
neutrophils, ELR-positive CXC Chemokines are able to recruit them to action.
C-Chemokines - Currently, only two of CC Chemokines have been identified.
These include the XCL1 and XCL2 chemokines which are characterized by two
cysteine, one of which is located at the N-terminus while the other is located
downstream.
12. CX3C chemokines - Like the other chemokines, the CX3C chemokines also
contain two cysteine at the N-terminus. However, the cysteine are separated by
three amino acids. CX3CL1, which is the only chemokine in this group, is not only
a chemo attractant, but also a cell adhesion molecule. To serve its function,
CXCL1 has to bind to CX3CR1, a receptor located on the cell that expresses it.
Chemokine receptors - These include the G-protein-coupled receptors (consisting
of 7-transmembrane α-helical segments) and atypical receptors are expressed on all
white cells involved in immunity. While each type of the receptors can bind to
different chemokines (within the same family), a single chemokine can also bind to
several receptorsubtypes. Regardless, according to studies, a majority of these
chemokines have been shown to display receptor specificity.
While regulating leukocytes through the peripheral lymphoid tissues is one of the
functions of chemokines, their primary role entails recruiting such cells as
neutrophils and T cells to the site of inflammation. Here, the migration of the
leukocytes to the affected site is achieved by the stimulation of actin filaments.
Some of the other important functions of chemokines include:
Promoting angiogenesis (CXC chemokines)
Wound healing (CXC chemokines)
Development of various non-lymphoid organs
Priming certain T cells
* For the most part chemokines are relatively small in size, ranging between 8 and
14 kDa.
* To achieve their functions, chemokines have to be released in large amounts so
as to establish a concentration gradient necessary to influence cell migration.
TUMOR NECROSIS FACTOR
Tumor Necrosis Factor(TNF) consists of a group of proteins involved in a number
of physiological and pathological processes.Currently, about 40 members of the
super family (TNF) have been identified with TNF-α and TNF-β being the most
notable examples.
Some of the other members of TNF include:
13. CD40 Ligand
OX40 Ligand
FAS Ligand
GITR Ligand
TNF-alpha (TNF-α)
Also known as TNF or TNFSF2, TNF-α is a multifunctional cytokine involved in
such processesas apoptosis and coagulation among others. In human beings, TNF-
α gene are located on chromosome6. This allows the cytokine to be expressed and
produced by suchimmune cells as macrophages, monocytes and T cells in
responseto invading pathogens or the presence of cytokines like IFN-y.
Some of the main characteristics of TNF-α include:
· Following activation of macrophages and other cells, TNF-α is synthesized as a
26-kD nonglycosylated type II membrane protein.
· Two types of TNFα that include mTNFα and sTNFα.
· Due to adipose tissue expression, TNF-α is sometimes referred to as an adipostat.
Functions of TNF-α
As mentioned, TNF-α is a multifunctional cytokine that ranges from immune roles
to programmed cell death.
Immune function - Like the other cytokines, TNF-α plays an important role in
immunity. In particular, TNF-α attracts certain immune cells to the affected site by
stimulating the expression of adhesion molecules by vascular endothelial cells.
This makes it possible for immune cells to adhere to blood vessel walls and
successfully migrate to the infected site and destroy invading pathogens (bacteria
and viruses).
Induces the production of chemokines that are involved in inflammatory
responses - These cytokines guide immune cells to the affected site.
Apoptosis - TNF-α promotes the programmed cell death of tumor cells by
promoting the recruitment of proteins involved in death signaling.
Biological functions - When produced in large amounts, TNF-α has been shown to
induce reduced blood pressure or shockduring such events as severe infections. In
14. some cases, however, a high concentration of this cytokine results in low blood
sugar concentration as well as intravascular thrombosis.
TNFβ - Also known as Lymphotoxin, TNFβ is a type II transmembrane protein.
The expression of this cytokine is stimulated by activated lymphocytes. With
regards to functions, TNFβ is a potent mediator involved in various immune and
inflammatory responses that have similarities to those of TNF-α.
Like TNF-α, TNF-β is also involved in the following processes:
Apoptosis
Coagulation
Cell proliferation and differentiation
CYTOKINE RECEPTORS
Cytokine receptors are cell surface receptors that bind specifically to
cytokines and transduce their signals, including chemokine
receptor, interleukin receptor, interferon receptor, tumor necrosis factor
receptor (TNF receptor), colony-stimulating factor receptor (CSF
receptor), growth factor receptors and TGF-beta super family receptors .
The patterns of expression of cytokine receptors are a product of
differentiation and provide for changes in physiological regulation. These
cytokine receptors enable cells to communicate with the extracellular
environment by responding to signals generated in the vicinity or in other
parts of the organism. Thus, the initial binding of cytokines to their receptors
is a key event that occurs rapidly, at very low cytokine concentrations, is
usually virtually irreversible, and leads to intracellular changes resulting in a
biologic response. The biologic response can vary between cytokine
receptors and from cell to cell but in general it involves gene expression,
changes in the cell cycle, and release of mediators such as cytokines
themselves.
The classification of cytokine receptors based on their three-dimensional structure
has been given:
15. Immunoglobulin (Ig) super family, which are ubiquitously present throughout
several cells and tissues of the vertebrate body, and share structural
homology with immunoglobulin (antibodies), cell adhesion molecules, and
even some cytokines. Examples: IL-1 receptor types.
Hemopoietic Growth Factor (type 1) family, whose members have certain
conserved motifs in their extracellular amino-acid domain. The IL-2 receptor
belongs to this chain, whose γ-chain (common to several other cytokines)
deficiency is directly responsible for the x-linked form of Severe Combined
Immunodeficiency (X-SCID).
Interferon (type 2) family, whose members are receptors for IFN β and γ.
Tumor necrosis factors (TNF) (type 3) family, whose members share
a cysteine-rich common extracellular binding domain, and includes several
other non-cytokine ligands like CD40, CD27 and CD30, besides the ligands on
which the family is named.
Seven transmembrane helix family, the ubiquitous receptor type of the
animal kingdom. All G protein-coupled receptors (for hormones and
neurotransmitters) belong to this family. Chemokine receptors, two of which
act as binding proteins for HIV (CD4 and CCR5), also belong to this family.
Interleukin-17 receptor (IL-17R) family, which shows little homology with
any other cytokine receptor family. Structural motifs conserved between
members of this family include: an extracellular fibronectin III-like domain, a
transmembrane domain and a cytoplasmic SERIF domain. The known members
of this family are as follows: IL-17RA, IL-17RB, IL-17RC, IL17RD and IL-
17RE.
BIO-FUNCTIONS OF CYTOKINES
They stimulate development of cellular and humeral immune response.
They induce inflammatory response.
They regulate hematopoiesis i.e. formation of blood cellular components.
They control cellular proliferation and differentiation.
They help in Healing wounds, tissue maintenance and repair.
Embryogenesis and organ development involves important mediators called
Cytokines.
Cytokines play a key role in neuro-immunological, neuro-endocrinological,
and neuro-regulatory processes.
16. Cytokines also regulate cell cycle, differentiation, migration, cell survival &
cell death, and cell transformation.
THERAPEUTICUSES OF CYTOKINES
I. Interferons are used in the treatment of viral diseases and cancer.
II. Several cytokines are used to enhance T-cell activation in
immunodeficiency diseases, e.g. IL-2, IFN-y etc.
III. IL-2 and Lymphokines activating killer cells are used in the treatment
of cancer.
IV. Anti-TNF antibodies are used in treating septic shocks.
V. Anti-IL-2R𝛼 is used in treatment of adult T-cell leukemia.
REFERENCES
• https://www.slideshare.net/MMASSY/lecture-cytokines
• https://www.verywellhealth.com/what-are-cytokines-189894
• https://www.onlinebiologynotes.com/cytokines-properties-receptors/
• https://www.sinobiological.com/research/receptors/cytokine-receptors
• https://en.wikipedia.org/wiki/Cytokine