The document provides an overview of the immune system, including both innate and adaptive defenses. It discusses the innate immune system's physical barriers, internal defenses like phagocytes and inflammation, and mechanisms like interferon and complement. It then covers the characteristics and components of the adaptive immune system, including humoral immunity mediated by antibodies and cell-mediated immunity involving T-cells. It describes antibody classes, targets, and functions, as well as processes like monoclonal antibody production and T-cell activation.
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.
Immunity are divided into nonspecific immunity and specific immunity. Examples of nonspecific immunity are skin, mucous membrane, and sebum. Specific immunity recognizes and respond to specific foreign substance. Specific immunity are divided into humoral response and cell-mediated response. Humoral response involves the production of antibodies while cell mediated immunity involve the cytotoxic T cells.
The document discusses the innate and adaptive immune systems. The innate system provides non-specific defenses like skin barriers and phagocytes. It responds quickly but does not improve over time. The adaptive system specifically targets pathogens using antibodies and lymphocytes. It takes longer to activate but has immunological memory. Both systems work together to protect the body through mechanisms like inflammation, phagocytosis, and antimicrobial proteins.
Immunity :
It is defined as the resistance exhibited by the host against any
foreign antigen including microorganisms.
Plays a major role in prevention of infectious diseases.
The immune system protects the body from disease through both innate and adaptive responses. The innate system provides immediate defense through barriers, inflammation, and nonspecific effector cells like macrophages and granulocytes. The adaptive system mounts an antigen-specific memory response involving B cells producing antibodies and T cell mediated immunity. A delicate balance of tolerance and immunity maintains protection against pathogens while avoiding autoimmunity. Disruptions can lead to immunodeficiency or autoimmune disease.
This document provides an overview of the human immune system and its defenses against disease. It discusses the external barriers of skin and mucus, internal responses like phagocytosis and inflammation, and the adaptive immune system involving B and T cells and antibody production. It covers active and passive immunity, immune responses, antigen recognition, and immune system disorders like autoimmunity, allergy, and AIDS. The immune system provides multilayered defenses that have largely evolved to protect the body from infectious diseases, toxins, and other foreign invaders.
Adaptive immunity is induced in response to specific antigens after collaboration between phagocytic cells, T and B lymphocytes, and production of immunoglobulins and lymphokines. There are two types of adaptive immunity: humoral immunity mediated by secreted antibodies and cell-mediated immunity which activates phagocytes, natural killer cells, cytotoxic T-lymphocytes and cytokines without antibodies. Humoral immunity involves B cell transformation into plasma cells secreting antibodies, while cell-mediated immunity blocks intracellular microbes by activating macrophages or cytotoxic T cells killing infected cells.
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.
Immunity are divided into nonspecific immunity and specific immunity. Examples of nonspecific immunity are skin, mucous membrane, and sebum. Specific immunity recognizes and respond to specific foreign substance. Specific immunity are divided into humoral response and cell-mediated response. Humoral response involves the production of antibodies while cell mediated immunity involve the cytotoxic T cells.
The document discusses the innate and adaptive immune systems. The innate system provides non-specific defenses like skin barriers and phagocytes. It responds quickly but does not improve over time. The adaptive system specifically targets pathogens using antibodies and lymphocytes. It takes longer to activate but has immunological memory. Both systems work together to protect the body through mechanisms like inflammation, phagocytosis, and antimicrobial proteins.
Immunity :
It is defined as the resistance exhibited by the host against any
foreign antigen including microorganisms.
Plays a major role in prevention of infectious diseases.
The immune system protects the body from disease through both innate and adaptive responses. The innate system provides immediate defense through barriers, inflammation, and nonspecific effector cells like macrophages and granulocytes. The adaptive system mounts an antigen-specific memory response involving B cells producing antibodies and T cell mediated immunity. A delicate balance of tolerance and immunity maintains protection against pathogens while avoiding autoimmunity. Disruptions can lead to immunodeficiency or autoimmune disease.
This document provides an overview of the human immune system and its defenses against disease. It discusses the external barriers of skin and mucus, internal responses like phagocytosis and inflammation, and the adaptive immune system involving B and T cells and antibody production. It covers active and passive immunity, immune responses, antigen recognition, and immune system disorders like autoimmunity, allergy, and AIDS. The immune system provides multilayered defenses that have largely evolved to protect the body from infectious diseases, toxins, and other foreign invaders.
Adaptive immunity is induced in response to specific antigens after collaboration between phagocytic cells, T and B lymphocytes, and production of immunoglobulins and lymphokines. There are two types of adaptive immunity: humoral immunity mediated by secreted antibodies and cell-mediated immunity which activates phagocytes, natural killer cells, cytotoxic T-lymphocytes and cytokines without antibodies. Humoral immunity involves B cell transformation into plasma cells secreting antibodies, while cell-mediated immunity blocks intracellular microbes by activating macrophages or cytotoxic T cells killing infected cells.
This document summarizes the physiology of the immune system. It describes the key cells that mediate the immune response, including leukocytes, lymphocytes, B cells, T cells, macrophages, and mast cells. It also outlines the innate and acquired immune responses. Phagocytosis by neutrophils, monocytes, and macrophages is discussed. The roles of T cells, B cells, plasma cells, and immunoglobulins in acquired immunity are summarized. Antigen presentation and the MHC restrictions of helper T cells and cytotoxic T cells are covered briefly.
The document summarizes the immune system. It discusses the organs of the immune system including primary organs like the bone marrow and thymus where immune cells develop and mature. Secondary organs where immune responses occur are also outlined, such as lymph nodes and spleen. The main cells of the immune system are described like lymphocytes (B cells, T cells, NK cells), phagocytes, dendritic cells, and granulocytes. The innate and adaptive immune responses are classified and the roles of antibodies and the complement system in immunity are summarized.
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
A brief covering basics of immunity understanding and also allowing students to understand with ease the concepts of innate immunity, adaptive immunity, Tcell, Bcell, MHC molecular genetics, and also cytokines and also its role in various disease.
The immune system protects the body from pathogens and other foreign substances. It has both innate and acquired immunity. Innate immunity provides immediate protection through barriers, chemicals, and cells. Acquired immunity develops from exposure through antibodies and lymphocytes. The components that work together in the immune response include lymphocytes like B and T cells, antibodies, lymph nodes, spleen, and other lymphoid tissues. Antigens are recognized by these immune cells, triggering a response to eliminate the pathogen.
The document summarizes key aspects of innate immunity. It discusses physical barriers like skin and mucous membranes, as well as cells and proteins involved in innate immunity. Cells discussed include phagocytes like macrophages and neutrophils, which kill microbes via phagocytosis and release of enzymes, reactive oxygen species, and nitric oxide. Proteins of the complement system and acute phase proteins are also summarized. The roles of fever, interferons, and tumor necrosis factors in the innate immune response are briefly described.
This document discusses immunopathology and the immune system. It covers:
- The two types of immunity - innate and adaptive - and their roles in defense.
- Key cells involved in innate immunity like neutrophils, macrophages, mast cells, basophils, and eosinophils.
- Adaptive immunity being antigen specific and involving B cells producing antibodies and T cells mediating cellular responses.
- Antigen presenting cells displaying antigens and activating T cells.
- Immune disorders occurring from deficiencies, hypersensitivities, autoimmunity, and idiopathic causes.
The ocular immune response involves local, regional, and systemic components. Locally, the conjunctiva, cornea, anterior chamber, and retina are involved. Regionally, the lacrimal gland and lymph nodes participate. Systemically, the spleen, thymus, and mucosal tissues are engaged. The tear film and its components, such as lysozyme, lactoferrin, and secretory IgA, play an important role in the ocular immune response by protecting the eye from pathogens. Specialized immune structures like the conjunctiva-associated lymphoid tissue (CALT) help regulate immunity in the eye. Dysregulation of the ocular immune system can lead to inflammatory conditions
Overview of the Immune System: Innate vs. Adaptive Defenses
Innate-Nonspecific Defenses
First Line of defense: Physical barriers
Second Line of defense:
- Major cellular components
Phagocytes
Basophils
Eosinophils
NK cells
- Chemical signals
Interferons
Complement Proteins
Inflammation
Fever (pyrogens)
The document discusses immunity and the immune system. It defines immunity and describes the innate and adaptive immune systems. The innate system provides non-specific defenses like anatomical barriers and cellular barriers. The adaptive system is antigen-specific and can develop immunological memory. Key organs of the immune system are also outlined, including the thymus, bone marrow, spleen and lymph nodes. Finally, it describes the main cells involved like lymphocytes, T cells, B cells, and their roles in the immune response.
1. The immune system has three lines of defense - physical barriers, nonspecific responses, and specific responses.
2. Nonspecific responses include inflammation, fever, phagocytosis by cells like neutrophils and macrophages, natural killer cells, interferon, and the complement system.
3. Specific responses are acquired through exposure to foreign substances and produce protective antibodies and memory cells.
The immune system protects the body from infection through two main branches: the innate immune system provides broad and immediate defense against pathogens, while the adaptive immune system provides highly specific immune responses and immunological memory. The adaptive immune system includes lymphocytes that recognize and respond to specific antigens through humoral immunity using antibodies or cell-mediated immunity using T-cells. Memory lymphocytes generated during an immune response enable faster and stronger protection upon reexposure to the same pathogen. Disorders can arise if the immune system is compromised, overactive, or attacks the body's own tissues.
This document summarizes key concepts about immunity. It describes the innate and acquired immune systems, including their components and functions. Innate immunity provides non-specific protection through barriers like skin and mucous membranes. Acquired immunity is specific and develops through exposure, providing long-term memory. Both active and passive immunity are discussed. The roles of B cells, T cells, antibodies, antigens, and other immune cells like macrophages, neutrophils, and natural killer cells are outlined.
Immune System Part II:The Innate Immune SystemFysiMack
Innate, or nonspecific, immunity is the defense system with which you were born. It protects you against all antigens. Innate immunity involves barriers that keep harmful materials from entering your body. These barriers form the first line of defense in the immune response
This document defines immunology and describes the innate and adaptive immune systems. The innate system provides non-specific first line defenses like physical barriers and soluble factors. It is evolutionary older and does not improve with repeated exposure. The adaptive system is activated after the innate system is overwhelmed and provides specific long-term immunity through cellular factors like T lymphocytes and soluble antibodies.
The main parts of the immune system are: white blood cells, antibodies, the complement system, the lymphatic system, the spleen, the thymus, and the bone marrow. These are the parts of your immune system that actively fight infection.
This is a presentation containing all notes for exams on the topic on immunology. It is mainly useful for Cambridge Medical students but some summaries may also be helpful for others!
1. Immunopathology refers to disorders that result from abnormal immune responses, including allergy, autoimmunity, immunodeficiency, and cancer.
2. Hypersensitivity reactions are exaggerated or misdirected immune responses, and include type I-IV reactions mediated by antibodies, mast cells, T cells or immune complexes.
3. Immunodeficiency diseases occur when components of the immune system are absent, including primary defects in B and T cells and secondary acquired deficiencies such as AIDS.
4. Cancer arises due to a failure of immune surveillance, allowing abnormal cells to proliferate unchecked through genetic mutations, oncogene activation, and viral insertion. The immune system normally detects and eliminates cancerous cells
The document discusses innate (non-specific) immunity. Innate immunity provides immediate defense against microbes through physical barriers and cells of the immune system like macrophages and neutrophils. It is always active and does not require prior exposure to generate a response. Innate immunity differs from acquired immunity in that acquired immunity is specific, develops over time through exposure, and can generate immunological memory.
Un antígeno es cualquier sustancia capaz de estimular la formación de anticuerpos específicos. Para ser considerada un antígeno, una sustancia debe cumplir dos requisitos: 1) ser extraña a la composición del organismo y 2) ser una macromolécula compleja de peso molecular superior a 5000 daltons. Las moléculas más pequeñas no son antigénicas a menos que estén unidas, y cuanto mayor es el peso molecular y la complejidad de la molécula, más fuerte será su capacidad antigénica.
The document discusses the nature of antigens and the major histocompatibility complex (MHC). It defines immunogens and antigens, noting that immunogens can trigger an immune response while not all antigens are immunogens. Antigens are usually large proteins or polysaccharides from foreign organisms. Factors like age, health, dose, and route of exposure can influence the immune response. The document also discusses epitopes, haptens, adjuvants, and the relationship of antigens to the host (autoantigens, alloantigens, heteroantigens). It provides details on MHC genes, class I and class II MHC structure and function in antigen processing and presentation to T cells.
This document summarizes the physiology of the immune system. It describes the key cells that mediate the immune response, including leukocytes, lymphocytes, B cells, T cells, macrophages, and mast cells. It also outlines the innate and acquired immune responses. Phagocytosis by neutrophils, monocytes, and macrophages is discussed. The roles of T cells, B cells, plasma cells, and immunoglobulins in acquired immunity are summarized. Antigen presentation and the MHC restrictions of helper T cells and cytotoxic T cells are covered briefly.
The document summarizes the immune system. It discusses the organs of the immune system including primary organs like the bone marrow and thymus where immune cells develop and mature. Secondary organs where immune responses occur are also outlined, such as lymph nodes and spleen. The main cells of the immune system are described like lymphocytes (B cells, T cells, NK cells), phagocytes, dendritic cells, and granulocytes. The innate and adaptive immune responses are classified and the roles of antibodies and the complement system in immunity are summarized.
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
A brief covering basics of immunity understanding and also allowing students to understand with ease the concepts of innate immunity, adaptive immunity, Tcell, Bcell, MHC molecular genetics, and also cytokines and also its role in various disease.
The immune system protects the body from pathogens and other foreign substances. It has both innate and acquired immunity. Innate immunity provides immediate protection through barriers, chemicals, and cells. Acquired immunity develops from exposure through antibodies and lymphocytes. The components that work together in the immune response include lymphocytes like B and T cells, antibodies, lymph nodes, spleen, and other lymphoid tissues. Antigens are recognized by these immune cells, triggering a response to eliminate the pathogen.
The document summarizes key aspects of innate immunity. It discusses physical barriers like skin and mucous membranes, as well as cells and proteins involved in innate immunity. Cells discussed include phagocytes like macrophages and neutrophils, which kill microbes via phagocytosis and release of enzymes, reactive oxygen species, and nitric oxide. Proteins of the complement system and acute phase proteins are also summarized. The roles of fever, interferons, and tumor necrosis factors in the innate immune response are briefly described.
This document discusses immunopathology and the immune system. It covers:
- The two types of immunity - innate and adaptive - and their roles in defense.
- Key cells involved in innate immunity like neutrophils, macrophages, mast cells, basophils, and eosinophils.
- Adaptive immunity being antigen specific and involving B cells producing antibodies and T cells mediating cellular responses.
- Antigen presenting cells displaying antigens and activating T cells.
- Immune disorders occurring from deficiencies, hypersensitivities, autoimmunity, and idiopathic causes.
The ocular immune response involves local, regional, and systemic components. Locally, the conjunctiva, cornea, anterior chamber, and retina are involved. Regionally, the lacrimal gland and lymph nodes participate. Systemically, the spleen, thymus, and mucosal tissues are engaged. The tear film and its components, such as lysozyme, lactoferrin, and secretory IgA, play an important role in the ocular immune response by protecting the eye from pathogens. Specialized immune structures like the conjunctiva-associated lymphoid tissue (CALT) help regulate immunity in the eye. Dysregulation of the ocular immune system can lead to inflammatory conditions
Overview of the Immune System: Innate vs. Adaptive Defenses
Innate-Nonspecific Defenses
First Line of defense: Physical barriers
Second Line of defense:
- Major cellular components
Phagocytes
Basophils
Eosinophils
NK cells
- Chemical signals
Interferons
Complement Proteins
Inflammation
Fever (pyrogens)
The document discusses immunity and the immune system. It defines immunity and describes the innate and adaptive immune systems. The innate system provides non-specific defenses like anatomical barriers and cellular barriers. The adaptive system is antigen-specific and can develop immunological memory. Key organs of the immune system are also outlined, including the thymus, bone marrow, spleen and lymph nodes. Finally, it describes the main cells involved like lymphocytes, T cells, B cells, and their roles in the immune response.
1. The immune system has three lines of defense - physical barriers, nonspecific responses, and specific responses.
2. Nonspecific responses include inflammation, fever, phagocytosis by cells like neutrophils and macrophages, natural killer cells, interferon, and the complement system.
3. Specific responses are acquired through exposure to foreign substances and produce protective antibodies and memory cells.
The immune system protects the body from infection through two main branches: the innate immune system provides broad and immediate defense against pathogens, while the adaptive immune system provides highly specific immune responses and immunological memory. The adaptive immune system includes lymphocytes that recognize and respond to specific antigens through humoral immunity using antibodies or cell-mediated immunity using T-cells. Memory lymphocytes generated during an immune response enable faster and stronger protection upon reexposure to the same pathogen. Disorders can arise if the immune system is compromised, overactive, or attacks the body's own tissues.
This document summarizes key concepts about immunity. It describes the innate and acquired immune systems, including their components and functions. Innate immunity provides non-specific protection through barriers like skin and mucous membranes. Acquired immunity is specific and develops through exposure, providing long-term memory. Both active and passive immunity are discussed. The roles of B cells, T cells, antibodies, antigens, and other immune cells like macrophages, neutrophils, and natural killer cells are outlined.
Immune System Part II:The Innate Immune SystemFysiMack
Innate, or nonspecific, immunity is the defense system with which you were born. It protects you against all antigens. Innate immunity involves barriers that keep harmful materials from entering your body. These barriers form the first line of defense in the immune response
This document defines immunology and describes the innate and adaptive immune systems. The innate system provides non-specific first line defenses like physical barriers and soluble factors. It is evolutionary older and does not improve with repeated exposure. The adaptive system is activated after the innate system is overwhelmed and provides specific long-term immunity through cellular factors like T lymphocytes and soluble antibodies.
The main parts of the immune system are: white blood cells, antibodies, the complement system, the lymphatic system, the spleen, the thymus, and the bone marrow. These are the parts of your immune system that actively fight infection.
This is a presentation containing all notes for exams on the topic on immunology. It is mainly useful for Cambridge Medical students but some summaries may also be helpful for others!
1. Immunopathology refers to disorders that result from abnormal immune responses, including allergy, autoimmunity, immunodeficiency, and cancer.
2. Hypersensitivity reactions are exaggerated or misdirected immune responses, and include type I-IV reactions mediated by antibodies, mast cells, T cells or immune complexes.
3. Immunodeficiency diseases occur when components of the immune system are absent, including primary defects in B and T cells and secondary acquired deficiencies such as AIDS.
4. Cancer arises due to a failure of immune surveillance, allowing abnormal cells to proliferate unchecked through genetic mutations, oncogene activation, and viral insertion. The immune system normally detects and eliminates cancerous cells
The document discusses innate (non-specific) immunity. Innate immunity provides immediate defense against microbes through physical barriers and cells of the immune system like macrophages and neutrophils. It is always active and does not require prior exposure to generate a response. Innate immunity differs from acquired immunity in that acquired immunity is specific, develops over time through exposure, and can generate immunological memory.
Un antígeno es cualquier sustancia capaz de estimular la formación de anticuerpos específicos. Para ser considerada un antígeno, una sustancia debe cumplir dos requisitos: 1) ser extraña a la composición del organismo y 2) ser una macromolécula compleja de peso molecular superior a 5000 daltons. Las moléculas más pequeñas no son antigénicas a menos que estén unidas, y cuanto mayor es el peso molecular y la complejidad de la molécula, más fuerte será su capacidad antigénica.
The document discusses the nature of antigens and the major histocompatibility complex (MHC). It defines immunogens and antigens, noting that immunogens can trigger an immune response while not all antigens are immunogens. Antigens are usually large proteins or polysaccharides from foreign organisms. Factors like age, health, dose, and route of exposure can influence the immune response. The document also discusses epitopes, haptens, adjuvants, and the relationship of antigens to the host (autoantigens, alloantigens, heteroantigens). It provides details on MHC genes, class I and class II MHC structure and function in antigen processing and presentation to T cells.
This document discusses antigens and antibodies. It defines antigens as any molecule that can bind specifically to an antibody. Antigens include sugars, lipids, proteins and more. They can be found on microbes or in the environment. The document discusses the properties of antigens including their ability to induce immune responses or tolerance. It also discusses immunogens versus haptens. Factors that influence antigen immunogenicity are also covered such as molecular size, composition, and an antigen's susceptibility to processing and presentation. The role of adjuvants in enhancing immune responses is also summarized.
This document discusses the immune system and its defenses against pathogens. It describes both nonspecific (innate) immunity and specific (adaptive) immunity. Nonspecific defenses include mechanical and chemical barriers that defend against any pathogen. Specific immunity involves antibody and lymphocyte responses that are targeted to specific antigens. The roles of B cells, T cells, antibodies, cytokines, complement system, inflammation and fever are summarized.
An antigen is any substance that reacts with lymphocytes, while immunogens generate immune responses. Haptens are small molecules that require coupling to carriers to induce responses. Antibody-antigen binding depends on weak interactions between sites on antibodies and epitopes on antigens. Antibodies are produced with a wide variety of binding sites to recognize different antigenic determinants. Factors like foreignness, size, structure, and route of administration influence a substance's immunogenicity.
Este documento describe los antígenos, incluyendo su definición, condiciones de antigenicidad, clasificación, antígenos de superficie celular, determinantes antigénicos, haptenos, reacción cruzada y adyuvantes. Los antígenos son sustancias extrañas que provocan una respuesta inmune y deben ser grandes, rígidas y químicamente complejas para ser antigénicos. Se clasifican según su origen, función y otros factores. Los determinantes antigénicos son las zonas especí
El documento define varios términos relacionados con antígenos e inmunogenicidad. Explica que un antígeno es una sustancia capaz de reaccionar con anticuerpos, mientras que un inmunógeno puede inducir una respuesta inmune. Los determinantes antigénicos son las partes específicas de una molécula a las que se unen los anticuerpos o células T. El documento también describe diferentes tipos de inmunógenos como xenoantígenos, aloantígenos y autoantígenos.
T-cells are a type of white blood cell that play a major role in the immune system by fighting infection. There are different types of T-cells that act in various ways to identify and destroy pathogens. T-cells mature in the thymus gland, where they develop receptors called TCRs that allow them to recognize antigens bound to MHC molecules on other cells. The MHC presents antigen fragments to T-cells to trigger an immune response against invading microbes.
The document summarizes the immune system's defenses against various pathogens. It describes both innate and acquired immunity. The innate immune system provides non-specific defenses like physical barriers, chemicals, and phagocytosis. The acquired immune system mounts pathogen-specific responses through antibodies, B cells, T cells, and cytokines. Together these defenses protect the body from bacteria, viruses, and parasites through mechanisms like inflammation, phagocytosis, and cell-mediated or antibody-mediated immunity.
There are two main types of immunity: innate and adaptive. Innate immunity provides initial defense through barriers, phagocytes, and proteins. Adaptive immunity has cellular and humoral components, mediated by T and B lymphocytes, which provide stronger, antigen-specific responses. Hypersensitivity reactions are caused by immune responses against harmless antigens, and include four types. Type I is immediate and antibody-mediated. Type II involves antibody and complement attack of cells. Type III occurs when immune complexes deposit in tissues. Type IV is delayed and cell-mediated. Disorders can also result from immune deficiencies or reactions against self.
The immune system has two lines of defense - innate (nonspecific) and adaptive (specific). The innate system provides immediate response and involves barriers like skin and mucous membranes. It also involves phagocytic cells and antimicrobial proteins. The adaptive system has antibody-mediated and cell-mediated responses and develops memory to mount a faster response upon repeat exposure. It involves B cells, T cells, antigens, and antigen-presenting cells.
L7 Introducation to Immunity FINAL.pptxRashaAlNagar
Lymphocytes precursors migrate from bone marrow to the thymus for processing to form “T” lymphocytes
Processing in the thymus :
Cells divide rapidly -
Each cell develops specific reactivity for one antigen
End result: thousands of T lymphocytes each with different specific reactivities for different antigens
Insures that each T lymphocyte will not react with the body’s own antigens (self antigen)
Then the processed cells leave thymus to lymphoid tissues
Most processing of T lymphocytes occurs prior to birth and completed after birth
T cells are activated for foreign cell attack when the cell express antigens on cell surface.
Learn to recognize foreign antigens only in combination with a person’s own tissue antigens
T cells respond to antigens only when they are bound to MHC proteins on the surface of antigen-presenting cells (macrophages, B lymphocytes, dendritic cells, somatic cells)
3 main types of T cells
CD8 cells (cytotoxic, or killer T cells)
Destroy host cells harboring antigen
CD4 cells (mostly helper T cells)
Modulate activities of other immune cells
Secrete chemicals that amplify the activity of other immune cells
Β-cell growth factor
T-cell growth factor (interleukin 2)
Macrophage-migration inhibition factor
CD4+CD25+T cells / Suppressor T- cells( regulatory T cells)
The document summarizes the immune system, including innate immunity as the first line of defense using barriers and phagocytic cells, and acquired immunity as the third line using lymphocytes and antibodies. It describes the different types of lymphocytes (B and T cells), antibodies, and immune responses (primary vs secondary; active vs passive). It also discusses allergies, HIV/AIDS, and the roles of the lymphatic system, MHC molecules, and leukocytes in the immune response.
The document summarizes the immune system, including innate immunity as the first line of defense using barriers and phagocytic cells, and acquired immunity as the third line using lymphocytes and antibodies. It describes the different types of lymphocytes (B and T cells), antibodies, and immune responses (primary vs secondary; active vs passive). It also discusses allergies, HIV/AIDS, and the roles of the lymphatic system, MHC molecules, and leukocytes in the immune response.
The document outlines the immune system's innate (nonspecific) defenses against pathogens. It describes the physical barriers of skin and mucous membranes that block pathogens from entering the body. It also discusses cellular components of innate immunity like phagocytes that engulf pathogens and natural killer cells that destroy abnormal cells. Additionally, it explains chemical signals produced during innate immune responses, such as interferons, complement proteins, and inflammatory mediators like those that cause fever.
Innate (nonspecific) system responds quickly and consists of:First line of defense – intact skin and mucosae prevent entry of microorganismsSecond line of defense – antimicrobial proteins, phagocytes, and other cells Inhibit spread of invaders throughout the bodyInflammation is its hallmark and most important mechanism
Adaptive (specific) defense systemThird line of defense – mounts attack against particular foreign substancesTakes longer to react than the innate systemWorks in conjunction with the innate system
The document summarizes key aspects of the immune system, including its defense mechanisms against pathogens. It discusses both nonspecific (innate) immunity and specific (acquired) immunity. Nonspecific immunity provides immediate protection and includes mechanical and chemical barriers on surfaces of the body. It also involves phagocytic cells that ingest foreign substances as well as natural killer cells and inflammatory responses. Specific immunity develops from exposure to pathogens and relies on lymphocytes recognizing specific antigens.
immunology_of_vaccines and immune mechanism.pptwalealufa
Vaccines contain antigens that stimulate the immune system to produce an immune response that is often similar to that produced by the natural infection. With vaccination, however, the recipient is not subjected to the disease and its potential complications.
This document summarizes different types of immunity and hypersensitivity reactions. It describes two broad categories of immunity: innate immunity which provides a first line of defense, and adaptive immunity which develops after exposure and recognizes specific antigens. It then discusses four types of hypersensitivity reactions (Type I-IV) mediated by different immune mechanisms in response to various antigens, providing examples of diseases associated with each type.
The lymphatic/immune system has two main roles:
1. To destroy and remove invading microbes and viruses from the body.
2. For the lymphatic system to also remove fat and excess fluids from the blood.
The major organs of the lymphatic/immune system include lymph, lymph nodes and vessels, white blood cells, and T- and B- cells. The immune system acts through both specific responses using B and T cells and non-specific responses like inflammation.
The document provides an introduction to immunology, describing the innate and adaptive immune responses. It defines immunology as the study of physiological mechanisms that defend the body from invading organisms like bacteria, viruses, fungi and parasites. The innate immune response acts immediately but non-specifically, while the adaptive response is antigen-specific and can generate immunological memory. Key cells of the immune system that contribute to these responses are described, including lymphocytes, macrophages, dendritic cells and others.
Introduction to Immunology and Serology Pt. 2nasarceda
The document provides an overview of immunology, including:
1. The innate and adaptive immune systems work together to defend the body. The innate system provides initial defenses while the adaptive system mounts specific responses.
2. Adaptive immunity involves B cells, T cells, and antigen-presenting cells. B cells produce antibodies while T cells help regulate the immune response.
3. When the immune system is dysfunctional, it can lead to issues like allergies, organ transplant rejection, autoimmune diseases, and immunodeficiencies.
Vaccines work by exposing the immune system to antigens from a pathogen. This triggers the production of antibodies and memory cells that can recognize and quickly eliminate the pathogen if exposed in the future. There are several types of vaccines, including those using whole inactivated or attenuated pathogens, as well as newer subunit and vector vaccines that deliver just the antigenic components. Vaccine development and approval is a rigorous process to ensure safety and efficacy.
The document summarizes the immune system and its response to pathogens. It describes:
1) The innate immune system provides non-specific defenses like skin barriers and phagocytic cells that provide immediate response.
2) The adaptive immune system mounts specific responses through B cells and T cells. It develops memory to mount a stronger response upon future exposures.
3) Antigens are recognized by B cells and T cells through antibody and T cell receptors. Helper T cells activate other immune cells through cytokine signaling. Cytotoxic T cells directly kill infected cells.
This document provides an overview of immunology, including a brief history, definitions of innate and adaptive immunity, and descriptions of the components and mechanisms of each. It discusses the functions of epithelial layers, types of immune responses, phagocytosis, and the roles and mechanisms of natural killer cells. Key topics covered include physical and chemical barriers, phagocytic cells, inflammation, acute phase proteins, cellular and humoral immune responses, and how pathogens can overcome phagocytosis.
A workshop hosted by the South African Journal of Science aimed at postgraduate students and early career researchers with little or no experience in writing and publishing journal articles.
Main Java[All of the Base Concepts}.docxadhitya5119
This is part 1 of my Java Learning Journey. This Contains Custom methods, classes, constructors, packages, multithreading , try- catch block, finally block and more.
বাংলাদেশের অর্থনৈতিক সমীক্ষা ২০২৪ [Bangladesh Economic Review 2024 Bangla.pdf] কম্পিউটার , ট্যাব ও স্মার্ট ফোন ভার্সন সহ সম্পূর্ণ বাংলা ই-বুক বা pdf বই " সুচিপত্র ...বুকমার্ক মেনু 🔖 ও হাইপার লিংক মেনু 📝👆 যুক্ত ..
আমাদের সবার জন্য খুব খুব গুরুত্বপূর্ণ একটি বই ..বিসিএস, ব্যাংক, ইউনিভার্সিটি ভর্তি ও যে কোন প্রতিযোগিতা মূলক পরীক্ষার জন্য এর খুব ইম্পরট্যান্ট একটি বিষয় ...তাছাড়া বাংলাদেশের সাম্প্রতিক যে কোন ডাটা বা তথ্য এই বইতে পাবেন ...
তাই একজন নাগরিক হিসাবে এই তথ্য গুলো আপনার জানা প্রয়োজন ...।
বিসিএস ও ব্যাংক এর লিখিত পরীক্ষা ...+এছাড়া মাধ্যমিক ও উচ্চমাধ্যমিকের স্টুডেন্টদের জন্য অনেক কাজে আসবে ...
LAND USE LAND COVER AND NDVI OF MIRZAPUR DISTRICT, UPRAHUL
This Dissertation explores the particular circumstances of Mirzapur, a region located in the
core of India. Mirzapur, with its varied terrains and abundant biodiversity, offers an optimal
environment for investigating the changes in vegetation cover dynamics. Our study utilizes
advanced technologies such as GIS (Geographic Information Systems) and Remote sensing to
analyze the transformations that have taken place over the course of a decade.
The complex relationship between human activities and the environment has been the focus
of extensive research and worry. As the global community grapples with swift urbanization,
population expansion, and economic progress, the effects on natural ecosystems are becoming
more evident. A crucial element of this impact is the alteration of vegetation cover, which plays a
significant role in maintaining the ecological equilibrium of our planet.Land serves as the foundation for all human activities and provides the necessary materials for
these activities. As the most crucial natural resource, its utilization by humans results in different
'Land uses,' which are determined by both human activities and the physical characteristics of the
land.
The utilization of land is impacted by human needs and environmental factors. In countries
like India, rapid population growth and the emphasis on extensive resource exploitation can lead
to significant land degradation, adversely affecting the region's land cover.
Therefore, human intervention has significantly influenced land use patterns over many
centuries, evolving its structure over time and space. In the present era, these changes have
accelerated due to factors such as agriculture and urbanization. Information regarding land use and
cover is essential for various planning and management tasks related to the Earth's surface,
providing crucial environmental data for scientific, resource management, policy purposes, and
diverse human activities.
Accurate understanding of land use and cover is imperative for the development planning
of any area. Consequently, a wide range of professionals, including earth system scientists, land
and water managers, and urban planners, are interested in obtaining data on land use and cover
changes, conversion trends, and other related patterns. The spatial dimensions of land use and
cover support policymakers and scientists in making well-informed decisions, as alterations in
these patterns indicate shifts in economic and social conditions. Monitoring such changes with the
help of Advanced technologies like Remote Sensing and Geographic Information Systems is
crucial for coordinated efforts across different administrative levels. Advanced technologies like
Remote Sensing and Geographic Information Systems
9
Changes in vegetation cover refer to variations in the distribution, composition, and overall
structure of plant communities across different temporal and spatial scales. These changes can
occur natural.
ISO/IEC 27001, ISO/IEC 42001, and GDPR: Best Practices for Implementation and...PECB
Denis is a dynamic and results-driven Chief Information Officer (CIO) with a distinguished career spanning information systems analysis and technical project management. With a proven track record of spearheading the design and delivery of cutting-edge Information Management solutions, he has consistently elevated business operations, streamlined reporting functions, and maximized process efficiency.
Certified as an ISO/IEC 27001: Information Security Management Systems (ISMS) Lead Implementer, Data Protection Officer, and Cyber Risks Analyst, Denis brings a heightened focus on data security, privacy, and cyber resilience to every endeavor.
His expertise extends across a diverse spectrum of reporting, database, and web development applications, underpinned by an exceptional grasp of data storage and virtualization technologies. His proficiency in application testing, database administration, and data cleansing ensures seamless execution of complex projects.
What sets Denis apart is his comprehensive understanding of Business and Systems Analysis technologies, honed through involvement in all phases of the Software Development Lifecycle (SDLC). From meticulous requirements gathering to precise analysis, innovative design, rigorous development, thorough testing, and successful implementation, he has consistently delivered exceptional results.
Throughout his career, he has taken on multifaceted roles, from leading technical project management teams to owning solutions that drive operational excellence. His conscientious and proactive approach is unwavering, whether he is working independently or collaboratively within a team. His ability to connect with colleagues on a personal level underscores his commitment to fostering a harmonious and productive workplace environment.
Date: May 29, 2024
Tags: Information Security, ISO/IEC 27001, ISO/IEC 42001, Artificial Intelligence, GDPR
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Find out more about ISO training and certification services
Training: ISO/IEC 27001 Information Security Management System - EN | PECB
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Article: https://pecb.com/article
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Slideshare: http://www.slideshare.net/PECBCERTIFICATION
it describes the bony anatomy including the femoral head , acetabulum, labrum . also discusses the capsule , ligaments . muscle that act on the hip joint and the range of motion are outlined. factors affecting hip joint stability and weight transmission through the joint are summarized.
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Reimagining Your Library Space: How to Increase the Vibes in Your Library No ...Diana Rendina
Librarians are leading the way in creating future-ready citizens – now we need to update our spaces to match. In this session, attendees will get inspiration for transforming their library spaces. You’ll learn how to survey students and patrons, create a focus group, and use design thinking to brainstorm ideas for your space. We’ll discuss budget friendly ways to change your space as well as how to find funding. No matter where you’re at, you’ll find ideas for reimagining your space in this session.
How to Manage Your Lost Opportunities in Odoo 17 CRMCeline George
Odoo 17 CRM allows us to track why we lose sales opportunities with "Lost Reasons." This helps analyze our sales process and identify areas for improvement. Here's how to configure lost reasons in Odoo 17 CRM
2. Immune System
functional system
rather than organ
system
Hematopoetic
Vasculature
Lymphatic
Fig 21.1
3. Innate vs. Adaptive Immune
System – Introduction
Innate: structural defenses; responds to
nonspecific foreign substances
First line: external surface epithelium & membranes
Second line: inflammatory processes – antimicrobial
proteins, phagocytes, etc.
Fig 21.1
4. Innate vs. Adaptive Immune
System – Introduction
Adaptive: responds to specific foreign substances
Innate & adaptive mechanisms work together
Fig 21.1
5. Innate, Surface Defenses
Skin
physical barrier to microbes
Keratin resistant to most bacterial enzymes & toxins
secretions are acidic pH 3-5
Mucosa
physical barrier & produces a variety of protective chemicals
Gastric mucosa
very acidic & produces proteolytic enzymes
Saliva & lacrimal fluid contain lysozyme
Mucous
traps bacteria & moves them away from epithelial surface
6. Innate, Internal Defenses
Based on recognition of surface
carbohydrates (glycocalyx)
Glycocalyx is recognized as “self” or “non-self”
Figure 3.3
8. Innate, Internal Defenses
Phagocytic mechanisms:
Adherence: cell binds to invader
Aided by opsonization (a chemical process that enhances
binding via complement & antibodies)
Ingestion: formation of phagolysosomes
Respiratory Bursts: merge phagosome with lysosome & flood
phagolysosome with free radicals (macrophage)
Defensins: proteins that crystallize out of solution & pierce
pathogen membranes (neutrophils)
10. Innate, Internal Defenses
Natural Killer Cells:
Small population of large granular lymphocytes
Non specific for “non-self”
Not phagocytic: attack is by release of perforins that
perforate the target cell plasma membrane.
Shortly after perforation the target nucleus disintegrates.
Release chemicals that enhance the inflammatory
response
11. Innate, Internal Defenses:
Inflammation
tissue response to injury
Triggered by injury – trauma, heat, chemical
irritation, infection, etc.
Beneficial effects
Prevents spread of injury
Disposes of cellular debris & pathogens
Promotes repair
12. Innate, Internal Defenses:
Inflammation
cardinal signs of inflammation
Redness
Heat
Swelling
Pain
(functional impairment Rigor)
Weapons of the Spanish Inquisition
13. Innate, Internal Defenses:
Inflammation
Inflammatory response: signs are
associated with vasodilation & increased
vascular permeability
Dilation: redness, heat
Permeability: edema, (increased pressure)
pain
Pain also associated with bacterial toxins &
some mediators (kinins, PGs)
14. Innate, Internal Defenses:
Inflammatory Response
Mechanisms causing vasodilation & vascular
permeability
Injured cells release inflammatory mediators
Histamines
Kinins
Prostaglandins
Complement
Cytokines (also activated by receptors on macrophages in
response to microbial glycocalyx)
15. Innate, Internal Defenses:
Inflammatory Response
Edema
Dilutes harmful substances
Provides nutrients (& O2) for repair
Enhances entry of clotting protein
Epithelial breaches also stimulate β-defensin
release from epithelial cells
18. Innate, Internal Defenses:
Inflammatory Response
Leukocytosis: leukocytosis inducing factors
released by injured cells promote rapid release
of WBCs from marrow
Margination: increased vascular permeability
causes decreased fluid in vessels; blood flow
slows & neutrophils are able to move to vessel
margins. Here endothelial markers (CAMs) allow
neutrophils to cling to vessel walls
(pavementing).
19. Innate, Internal Defenses:
Inflammatory Response
Diapedesis: neutrophils migrate through
capillary walls
Chemotaxis – inflammatory chemicals attract
neutrophils to move up the chemical
concentration gradient (neutrophils respond first)
As the process continues, monocytes diapedes
into the area & become macrophages. With
chronic inflammation, macrophages
predominate
21. Innate, Internal Defenses:
Inflammatory Response
Macrophages clean up cellular debris &
pathogens
If pathogens were associated with the injury,
activation of the complement cascade occurs &
elements of adaptive immunity join the process
22. Innate, Internal Defenses
Viral replication – (viruses lack metabolic
processes) Viruses release nucleic acid (RNA or
DNA) into cytoplasm. The information on the
nucleic acid is incorporated into the cell’s DNA.
Normal cellular mechanisms then produce viral
structural components. Multiple new viral
particles are produced & released from the cell
(sometimes killing the cell)
23. Innate, Internal Defenses
Antiviral proteins: interferon & complement
Interferon: some cells produce & release
interferons (IFNs) when invaded by virus
Released interferons stimulate nearby cells to
produce proteins (PKR) that interfere with viral
replication by disrupting protein synthesis & the
ribosome
Not virus specific.
25. Innate, Internal Defenses
Complement – a group of plasma proteins (20)
that are activated in the presence of foreign
substances
Complement activation enhances & amplifies
inflammation
Bacteria & some other cell types are lysed by
complement activation
Complement activation enhances both innate &
adaptive defenses
26. Innate, Internal Defenses
Complement activation pathways
Classical pathway: requires antibodies
Antibodies bind to target (antigen)
Complement protein C1 binds to the antibody-
antigen complex (complement fixation)
Alternative pathway: complement factors interact with
microorganism glycocalyx
Both pathways lead to a cascade of protein activation,
leading to activation of C3
27. Innate, Internal Defenses
C3 is the start of the; Final Common Pathway
C3 cleaves to form C3a & C3b
C3a (& C5a) enhance inflammation by increasing
histamine release, increasing vascular permeability &
stimulating chemotaxis
C3b coats bacterial membrane supplying adhesion
points (opsonization)
C3b initiates the cascade forming the membrane
attack complex (MAC)
The MAC forms a hole in the cell membrane &
enhances Ca2+
influx cell lysis
29. Innate, Internal Defenses
C-reactive proteins (CRP) produced by the liver
in response to inflammatory molecules can
activate the classical pathway by binding to
membrane & activating C1. Also participates in
opsonization.
Fever – a systemic response to infection.
Leukocytes & macrophages release pyrogens
that raise the hypothalamic “set point” for
temperature
31. Adaptive Defenses: Characteristics
Specificity: directed at specific targets
Systemic: not restricted to initial site of infection /
invasion
Memory: after initial exposure & activation, a
more rapid & more vigorous response is made
to subsequent exposures to pathogens
(secondary response)
32. Adaptive Defenses: Components
Humoral Immunity: (antibody mediated immunity)
provided by antibodies floating free in body fluids
Cell mediated immunity:
lymphocytes directly attack specific invaders by
lysis or indirect attack by initiating inflammation
and/or activating other lymphocytes &
macrophages
33. Adaptive, Humoral Immunity
Antigen = any substance that can mobilize the
immune system & provoke an immune response*
*Humoral and/or cell mediated
34. Adaptive, Humoral Immunity
Complete antigens (proteins, nucleic acids,
lipids, polysaccharides):
Immunogenicity: the ability to stimulate specific
lymphocytes & specific antibodies
Reactivity: the ability to react with activated
lymphocytes & antibodies
Hapten (an incomplete antigen): a smaller
molecule that is not immunogenic until attached
to proteins
35. Adaptive, Humoral Immunity
Antigenic determinants: sites on an antigenic molecule
that are immunogenic
Epitope
Major Histocompatibility Complex (MHC): cell surface
glycoproteins associated with self recognition
Figure 21.7
37. Adaptive Immune System: Cells
Lymphocytes: initially uncommitted
T-cells: are sorted in the Thymus
Positive selection: recognize MHC survive
Negative selection: react against to self-antigens on MHC killed
2% of initial T-cell precursors
T-cells manage the immune response
B-cells: are sorted in the marrow by an incompletely understood process
Figure 21.9
38. Adaptive Immune System: Cells
Immunocompetence: as T- or B-cells mature
they become immunocompetent, they display
receptors on their cell membrane for a specific
antigen.
All of the receptors on one cell are identical;
immunity depends upon genetic coding for
appropriate receptors.
39. Adaptive Immune System: Cells
Antigen Presenting Cells (APCs)
APCs ingest foreign material, then present
antigenic fragments on their cell surface where
they are recognized by T-cells
T-cells: respond to antigen only if it is displayed on plasma membrane.
APCs: Macrophages & B lymphocytes
Interactions between APCs & lymphocytes &
lymphocyte-lymphocyte interactions are critical
to immune response
40. Adaptive, Humoral response
Humoral response (clonal selection)
B-cells: Antigen challenge to naïve
immunocompetent B-cell
Antigen binds to B-cell receptors & form cross-
links between receptors
Cross linked antigen-receptor complex
undergoes endocytosis; B-cell presents to T-cell
41.
42.
43. Humoral Immunity
Active humoral immunity:
B-cells encounter & respond to antigen to produce an
antibody
Passive humoral immunity:
Introduced “non-native” antibody
44. Active Humoral Immunity
Naturally acquired: natural exposure to antigen
(i.e. infection)
Artificially acquired: vaccines; dead/attenuated
or fragmented pathogen injected to elicit an
immune response
Bestow immunity without disease; primary response
Booster shots (secondary response); intensify response
Shortcomings – adverse reactions & the immunity is less durable
(poor memory) & has less cell mediated component
45. Passive Humoral Immunity
Natural: maternal antibody crosses the placental
barrier conferring temporary immunity to the
baby (degrades after a few months)
Artificial: antibodies harvested from an outside
source given by injection protect from immediate
threat but no memory is formed (antitoxins,
antivenins , gamma globulin, etc.)
47. Antibodies
Constant (C) region defines antibody class
determines chemical & cellular interactions
determines how class functions to eliminate antigens
49. Antibody Classes
IgG: the most abundant circulating Ig. The
dominant circulating Ig of the primary & the
secondary response. Crosses the placenta.
Complement binding (Monomer).
IgA: the Ig of secretions. Helps prevent antigen
penetration of membranes (Dimer).
IgD: the Ig of B-cell activation. Found on B-cell
surface (Monomer).
50. Antibody Classes
IgM: occurs as a monomer & a pentamer
Occurs on the B-cell surface (Monomer).
The Ig of early primary plasma cell response,
circulating antibody; a potent agglutinator.
Complement binding (Pentamer).
51. Antibody Classes
IgE: the Ig associated with allergies.
Stem binds to mast cells & basophils.
Receptor binding results in histamine release
& inflammation.
Found mostly in mucosa of respiratory & GI
tract (Monomer).
52. Antibody Targets & Functions
Immune complex formation = antigen-antibody binding.
All the following events are initiated by antigen-antibody
binding.
Complement fixation:
Neutralization:
Agglutination:
Precipitation:
Inflammation & phagocytosis prompted by debris
53. Antibody Targets & Functions Complement fixation: cells & bacteria.
Immune complex formation exposes a complement binding site on the C region of the Ig.
Complement fixation results in cell lysis.
Neutralization: immune complex formation blocks specific sites on virus or toxin &
prohibit binding to tissues
Agglutination: cells are crosslinked by immune complexes & clump together
Precipitation: soluble molecules (such as toxins) are crosslinked, become insoluble,
& precipitate out of the solution
Inflammation & phagocytosis prompted by debris
Figure 21.14
54. Antibody Targets & Functions
Monoclonal antibodies: antibodies produced by
descendants of a single cell
Pure antibody preparations that are specific for a
single antigenic determinant
Research / diagnostic / therapeutic use
55. Cell Mediated Immune Response
T-cell activation: involves recognition of PM
surface antigens only
Antigen is combined with MHC & displayed on PM
T-cell receptors: bind to the MHC & are stimulated by
the associated antigen
The addition of a co-stimulator (cytokines,
interleukins, etc) prompts the T-cell to form a clone
In the absence of a co-stimulator the T-cell becomes
tolerant to antigen (anergy)
56. Cell Mediated: MHC
MHC occurs as two classes
MHC I on virtually all tissue cells
MHC II only on PM some immune system cells
57. Cell Mediated:
MHC display properties
MHC I on virtually all tissue cells
Display only proteins produced inside the cell
Endogenous antigens = foreign proteins produced by
the cell (viral / cancer)
Stimulate the CD8* cell population
form cytotoxic T-cells (Killer T, TC)
*formerly T8 cells
Figure 21.16a
58. Cell Mediated:
MHC display properties
MHC II found only on PM of B-cells, some T-cells & APCs
Display proteins derived from a phagocytized target
Exogenous antigen: foreign protein from outside the cell –
presented to PM surface
Stimulates the CD4* cell population
form Helper T-cells (TH)
*formerly T4 cells
Figure 21.16b
59. Cell Mediated: T-cell roles
Helper T-cells (TH) stimulate B-cells
& other T-cells to proliferate
Figure 21.18
60. Cell Mediated: T-cell roles
Activated TH cells interact with B-
cells displaying antigen & produce
cytokines that prompt the B-cell to
mature & form antibody
Figure 21.18
61. Cell Mediated: T-cell roles
TH cells also produce cytokines
that promote TC cells
TH cells recruit other WBCs &
amplify innate defenses
(inflammatory)
Subpopulations of TH cells
specialize in specific sets of
activations
Figure 21.18
62. Cell Mediated: T-cell roles
Cytotoxic T-cells (TC, Killer T): directly attack &
kill cells with specific antigen
Activated TC cells are co-stimulated by TH cells
63. Cell Mediated:
T-cell roles
TC mechanism (Cytotoxic T-cells, Killer T)
TC binds to cell & releases perforin & granzymes
In the presence of Ca2+
perforin forms pores in target cell PM
Granzymes enter through pores & degrade cellular contents
TC then detaches & moves on
Macrophages clean up
Figure 21.19a
64. Cell Mediated: T-cell roles
Other T-cells
*Regulatory T-cells (TReg): release inhibitory cytokines
that suppress B-cell & T-cell activity
Help to prevent autoimmune events
*formerly Suppressor T (TS)
Gamma Delta T-cells (Tgd): live in the intestine.
Function in surveillance & are triggered much like NK
cells
65. Organ Transplants/Rejections
Types of Organ Transplants
Autograft: tissue graft from one body site to another
(same person)
Isograft: graft received from a genetically identical
donor (identical twin)
Allograft: graft received from genetically non-identical
donor (same species)
Xenograft: graft received from another species of
animal
66. Organ Transplants/Rejections
Transplant rejection: mediated by the immune
system (especially TC, NK, antibodies)
Auto/Isograft: MHC compatible
Xenograft: most MHC incompatible
Allograft: attempt to obtain the best MHC match
67. Organ Transplants/Rejections
Immunosuppressive therapy: used to
delay/prevent rejection
Corticosteroids: suppress inflammation
Antiproliferative: prevent/kill rapidly dividing cells
Immunosuppressant: prevent/kill rapidly dividing cells
Side effects tend to be harsh
Increased risk of infection
68. Immunologic Dysfunction
Immunodeficiency
Congenital/Genetic: varied inborn errors
Acquired:
Drugs: immunosuppressive / cancer drugs
Radiation therapy – marrow
Cancer: can be viewed as a failure of immune
surveillance
Hodgkin’s disease: lymph node cancer
AIDS/HIV: kills TH cells
69. Immunologic Dysfunction
Autoimmune disease: production of antibody &
TH against self tissues
Examples & tissue effected
Multiple sclerosis: white matter of nervous system
Graves disease: thyroid
Type I diabetes mellitus: beta cells of pancreas
Systemic Lupus Erythrematosis: (anti DNA) kidneys, heart,
lungs & skin
Rheumatoid Arthritis: destroys joints (cartilage)
Glomerulonephritis: impaired renal function (may be
secondary to other autoimmune disease)
70. Immunologic Dysfunction
Mechanisms of immunologic dysfunction
Failure of lymphocyte programming
New self antigens
Gene mutation
Structural change – haptens, infection
Foreign antigens that closely resemble self antigen
resulting in cross reactivity.
71. Immunologic Dysfunction
Hypersensitivities (Allergies): the
immune system responds to a
harmless substance as if it were a
threat.
Allergen = antigens of an
allergic response
Figure 21.21
72. Hypersensitivities: Types
Immediate hypersensitivity
(Type I): symptoms within
seconds of exposure to an
allergen
(requires sensitization =
previous exposure)
Figure 21.21
73. Hypersensitivities: Type I
Anaphylaxis (IgE mediated; mast / basophils)
Local: histamine induced vasodilation & increased
permeability. Watery eyes, runny nose, itching &
redness. Respiratory allergy induced asthma
Systemic: anaphylactic shock: associated with
allergens that have systemic distribution. Widespread
vasodilation, airway swelling
Atopy: the tendency to display Type I symptoms
to certain environmental antigens without prior
sensitization
74. Hypersensitivities: Types II & III
Subacute hypersensitivity (IgG & IgM mediated)
Cytotoxic reactions (Type II): antibodies bind to cellular
antigens promoting complement fixation / inflammation /
phagocytosis (transfusion reaction)
Immune complex h. (Type III): widely distributed antigen
reacts with antibody.
Antigen-antibody complexes cannot be cleared; persistent
inflammation / tissue damage (farmer’s lung; associated with
autoimmune disorders)
75. Hypersensitivities: Type IV
Delayed hypersensitivity (cell mediated) takes
one to three days to react.
Involves TC, TH1 & macrophages.
Allergic contact dermatitis (poison ivy, heavy metals,
TB tine tests).
Agents act as haptens & elicit response after binding
to tissue
76. Developmental Aspects of the
Immune System
Stem cells arise from embryologic liver & spleen
Self tolerance develops in Thymus (T-cells) &
bone marrow (B-cells)
Immunocompetence: the “library” of receptors is
genetically determined
Immune system degrades with aging
77.
78. Red
bone marrow
1
2
3
Immunocompetent,
but still naive,
lymphocyte
migrates via blood
Mature (antigen-activated)
immunocompetent lymphocytes
circulate continuously in the
bloodstream & lymph & throughout
the lymphoid organs of the body.
Key: = Site of lymphocyte origin
= Site of development of immunocompetence
as B or T cells; primary lymphoid organs
= Site of antigen challenge & final
differentiation to activated B & T cellsImmature
lymphocytesCirculation in
blood
1
1 Lymphocytes destined to become T
cells migrate to the thymus & develop
immunocompetence there. B cells
develop immunocompetence in red
bone marrow.
Thymus
Bone
marrow
Lymph nodes,
spleen, & other
lymphoid tissues
2 2 After leaving the thymus or bone
marrow as naive immunocompetent
cells, lymphocytes “seed” the lymph
nodes, spleen, & other lymphoid
tissues where the antigen challenge
occurs.
3 3
Activated
immunocompetent
B & T cells
recirculate in blood
& lymph
Immunocompetent B or T cells
Figure 21.8