The document summarizes key aspects of the adaptive immune system, including the roles of T lymphocytes and B lymphocytes. It discusses:
1) The two main types of lymphocytes are T lymphocytes and B lymphocytes. T lymphocytes mediate cell-mediated immunity while B lymphocytes mediate antibody-mediated or humoral immunity.
2) Helper T cells recognize antigens presented by antigen-presenting cells and activate other immune cells like B cells and cytotoxic T cells. Cytotoxic T cells directly kill infected cells.
3) B cells produce antibodies that target extracellular pathogens. Upon activation by helper T cells, B cells differentiate into plasma cells that secrete large amounts of antibodies, establishing antibody-mediated immunity.
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
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
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
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
T-Cell Activation
• Concept of immune response
• T cell-mediated immune response
• B cell-mediated immune response
I. Concept of immune response
• A collective and coordinated response to the introduction of foreign substances in an individual mediated by the cells and molecules in the immune system.
II. T cell-mediated immune response
• Cell-mediated immunity is the arm of the adaptive immune response whose role is to combat infection of intracellular pathogens, such as intracellular bacteria (mycobacteria, listeria monocytogens), viruses, protozoa, etc.
T-Cell Activation
• Concept of immune response
• T cell-mediated immune response
• B cell-mediated immune response
I. Concept of immune response
• A collective and coordinated response to the introduction of foreign substances in an individual mediated by the cells and molecules in the immune system.
II. T cell-mediated immune response
• Cell-mediated immunity is the arm of the adaptive immune response whose role is to combat infection of intracellular pathogens, such as intracellular bacteria (mycobacteria, listeria monocytogens), viruses, protozoa, etc.
A detailed description of Cell mediated immunity and antibody mediated immunity. Lecture notes for medical, dental and paramedical undergraduate students.
Lymphocytic cells involved in human immune systemAbhay jha
This slide share was basically based on the immune system of human regarding the cellular activity involve to save human body against any pathogenic attack and we are talking about the lymphatic cells wich are T cells B cells natural kills T cell (NKT) innate lymphatic cells and their functions in our body.
Cells involved in immune response by faunafondnessfaunafondness
Content :- Cells involved in immune response
1. Types of immune cells
2. Their production
3. Function of immune cells
4. T-cells, B-cells, Macrophages, monocytes, dendritic cells.
Immune System - The immune system is a complex network of cells and proteins that defends the body against infection.
The immune system keeps a record of every microbe it has ever defeated so it can recognize and destroy the microbe quickly if it enters the body again.
Abnormalities of the immune system can lead to allergic disease, immunodeficiencies and autoimmune disorders.
Antigen - Any factors or agents that can enter the body and create an immune response are called antigen.
Formation of immune cells - Immune cells are produced by hematopoietic stem cell in bone marrow
Hematopoietic stem cells are self-renewing and reside in the medulla of the bone ( bone marrow ).
HSCs are divided into two main lineages, lymphoid progenitor cells or myeloid progenitor cells.
Myeloid cells - Neutrophil, Eosinophil, Basophil, Mast cells, Monocyte, Macrophage, Dendritic Cell
Lymphoid cells - B Lymphocytes,
T Lymphocyte, NK Cells
Antigen presenting cells - Professional antigen presenting
cells : Macrophage, Dendritic cell, B Lymphocyte
Non professional antigen presenting cell: Non-professional antigen presenting cells include all nucleated cell types in the body.
Proteins of immune system - Set of serum proteins that co-operate with both Innate and adaptive immune system to eliminate blood and tissue pathogen.
Organs of immune cells - Spleen, Lymph node, Tonsils , MALT, Bone marrow, Thymus
Types of immunity -
Innate Immunity: Innate immune response is in born and is the first line of defense against pathogen
Adaptive immunity: Antigenic specificity. It have immunological memory
Immune Receptors - It is a specialized structures found in the cell membrane. They are mainly composed of proteins, which bind to pathogens and causes a response in immune system
Richard's entangled aventures in wonderlandRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
(May 29th, 2024) Advancements in Intravital Microscopy- Insights for Preclini...Scintica Instrumentation
Intravital microscopy (IVM) is a powerful tool utilized to study cellular behavior over time and space in vivo. Much of our understanding of cell biology has been accomplished using various in vitro and ex vivo methods; however, these studies do not necessarily reflect the natural dynamics of biological processes. Unlike traditional cell culture or fixed tissue imaging, IVM allows for the ultra-fast high-resolution imaging of cellular processes over time and space and were studied in its natural environment. Real-time visualization of biological processes in the context of an intact organism helps maintain physiological relevance and provide insights into the progression of disease, response to treatments or developmental processes.
In this webinar we give an overview of advanced applications of the IVM system in preclinical research. IVIM technology is a provider of all-in-one intravital microscopy systems and solutions optimized for in vivo imaging of live animal models at sub-micron resolution. The system’s unique features and user-friendly software enables researchers to probe fast dynamic biological processes such as immune cell tracking, cell-cell interaction as well as vascularization and tumor metastasis with exceptional detail. This webinar will also give an overview of IVM being utilized in drug development, offering a view into the intricate interaction between drugs/nanoparticles and tissues in vivo and allows for the evaluation of therapeutic intervention in a variety of tissues and organs. This interdisciplinary collaboration continues to drive the advancements of novel therapeutic strategies.
Introduction:
RNA interference (RNAi) or Post-Transcriptional Gene Silencing (PTGS) is an important biological process for modulating eukaryotic gene expression.
It is highly conserved process of posttranscriptional gene silencing by which double stranded RNA (dsRNA) causes sequence-specific degradation of mRNA sequences.
dsRNA-induced gene silencing (RNAi) is reported in a wide range of eukaryotes ranging from worms, insects, mammals and plants.
This process mediates resistance to both endogenous parasitic and exogenous pathogenic nucleic acids, and regulates the expression of protein-coding genes.
What are small ncRNAs?
micro RNA (miRNA)
short interfering RNA (siRNA)
Properties of small non-coding RNA:
Involved in silencing mRNA transcripts.
Called “small” because they are usually only about 21-24 nucleotides long.
Synthesized by first cutting up longer precursor sequences (like the 61nt one that Lee discovered).
Silence an mRNA by base pairing with some sequence on the mRNA.
Discovery of siRNA?
The first small RNA:
In 1993 Rosalind Lee (Victor Ambros lab) was studying a non- coding gene in C. elegans, lin-4, that was involved in silencing of another gene, lin-14, at the appropriate time in the
development of the worm C. elegans.
Two small transcripts of lin-4 (22nt and 61nt) were found to be complementary to a sequence in the 3' UTR of lin-14.
Because lin-4 encoded no protein, she deduced that it must be these transcripts that are causing the silencing by RNA-RNA interactions.
Types of RNAi ( non coding RNA)
MiRNA
Length (23-25 nt)
Trans acting
Binds with target MRNA in mismatch
Translation inhibition
Si RNA
Length 21 nt.
Cis acting
Bind with target Mrna in perfect complementary sequence
Piwi-RNA
Length ; 25 to 36 nt.
Expressed in Germ Cells
Regulates trnasposomes activity
MECHANISM OF RNAI:
First the double-stranded RNA teams up with a protein complex named Dicer, which cuts the long RNA into short pieces.
Then another protein complex called RISC (RNA-induced silencing complex) discards one of the two RNA strands.
The RISC-docked, single-stranded RNA then pairs with the homologous mRNA and destroys it.
THE RISC COMPLEX:
RISC is large(>500kD) RNA multi- protein Binding complex which triggers MRNA degradation in response to MRNA
Unwinding of double stranded Si RNA by ATP independent Helicase
Active component of RISC is Ago proteins( ENDONUCLEASE) which cleave target MRNA.
DICER: endonuclease (RNase Family III)
Argonaute: Central Component of the RNA-Induced Silencing Complex (RISC)
One strand of the dsRNA produced by Dicer is retained in the RISC complex in association with Argonaute
ARGONAUTE PROTEIN :
1.PAZ(PIWI/Argonaute/ Zwille)- Recognition of target MRNA
2.PIWI (p-element induced wimpy Testis)- breaks Phosphodiester bond of mRNA.)RNAse H activity.
MiRNA:
The Double-stranded RNAs are naturally produced in eukaryotic cells during development, and they have a key role in regulating gene expression .
Nutraceutical market, scope and growth: Herbal drug technologyLokesh Patil
As consumer awareness of health and wellness rises, the nutraceutical market—which includes goods like functional meals, drinks, and dietary supplements that provide health advantages beyond basic nutrition—is growing significantly. As healthcare expenses rise, the population ages, and people want natural and preventative health solutions more and more, this industry is increasing quickly. Further driving market expansion are product formulation innovations and the use of cutting-edge technology for customized nutrition. With its worldwide reach, the nutraceutical industry is expected to keep growing and provide significant chances for research and investment in a number of categories, including vitamins, minerals, probiotics, and herbal supplements.
Richard's aventures in two entangled wonderlandsRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
3. Adaptive Immunity
• Immunity that an organism develops during
lifetime
• Develops after exposure to antigens
• Invovles the activity of lymphocytes
• Includes 3rd
line of defense
4. Adaptive Immunity (Specific immunity)
• Specificity
• Memory
• Ability to distinguish b/w self
vs non-self
• T and B cell
5. Types of Adaptive Immunity
1. Antibody-Mediated Immunity (AMI) or
Humoral Immunity
– B lymphocytes
2. Cell-Mediated Immunity (CMI) or Cellular
Immunity
– T lymphocytes
Note: B and T cells ……..blood, lymph, lymphoid
tissues such as spleen, lymph nodes etc.
7. CHECKPOINT
• 1. What are the two main types of
lymphocytes?
• 2. What is an antigen? Name some examples.
8. Cell-Mediated Immune Response
• T cells
• Immune resoponse to infected cells
( viruses, bacteria and parasites (Pathogens) within
cells)
• Defense against cancer and transplant cells
•Chapter 21, Immune System •8
9. T-Lymphocytes
• Helper T cells – secrete CYTOKINES
help B cells Tc cells to divide
• Cytotoxic T cells (killer T cells)
Kill infected body cells
• Memory T cells
remain in body
10. How do T cells know a cell is
infected?
• Infected cells digest some pathogens and MHC
proteins carry pieces to cell surface
• Antigen Presenting Cell (APC)
• Alerts Helper T cells
•MHC proteins displaying
foreign antigens
infected
cell
•T cell with
antigen receptors
•TH cell
11. •Chapter 21, Immune System •11
• MHC proteins,mark a cell as self
• The two classes of MHC proteins are:
– Class I MHC proteins – found on virtually all body cells
– Class II MHC proteins – found on certain cells in the
immune response
MHC Proteins
14. Helper T Cells (TH)
• bind to other white blood cells that have
previously encountered an antigen
– stimulate proliferation of other T cells
– Stimulate B cells that have already become bound
to antigen
• Without TH, there is no immune response
•Chapter 21, Immune System •14
15. The central role of Helper T Cells (Boss)
•Chapter 21, Immune System •15
•Figure 21.17a
16. Cytotoxic T Cell (Tc)
• Destroys infected body cells
– binds to target cell
– secretes perforin protein
• punctures cell membrane of infected cell
– apoptosis
•Chapter 21, Immune System •16
17. Cytotoxic T cells
•Killer T cell
binds to
infected cell
• Destroys infected body cells
– binds to target cell
– secretes perforin protein
• punctures cell membrane of infected cell
– apoptosis
•infected cell
•destroyed
19. •Cytotoxic T cell
•1 •2
•Accessory
protein
•Class I MHC
molecule
•Infected
cell
•Antigen
receptor
•Antigen
fragment
•Perforin
•Pore
•Gran-
zymes
20. The killing action of
cytoxic T cells on
an infected host
cell.
•Cytotoxic T cell
•3•1 •2
•Accessory
protein
•Class I MHC
molecule
•Infected
cell
•Antigen
receptor
•Antigen
fragment
•Perforin
•Pore
•Gran-
zymes
•Released
cytotoxic
T cell
•Dying
infected cell
22. • Human Immunodeficiency Virus
– virus infects and destroys helper T cells
• helper T cells don’t activate rest of immune system: killer T
cells & B cells
• AIDS: Acquired ImmunoDeficiency Syndrome
– infections by opportunistic
diseases
– death usually from
– “opportunistic” infections
• pneumonia, cancers
HIV & AIDS
•HIV infected T cell
23. ANTIBODY-MEDIATED (HUMORAL) IMMUNITY
• targets extracellular microorganisms (Bacteria
and viruses circulating in the blood)
• B-lymphocytes (B cells)………. Antibodies
• Antibodies… extracellular fluids and surface of B
cells
27. Antibody-mediated (humoral) immunity = AMI
• 1- Macrophages phagocytize
a pathogen and present an
antigen to a matching
helper-T cell
• 2- At the same time, some
pathogens contact B-cells
matching the pathogen’s
antigens
• The helper-T cells multiply,
secrete lymphokines which
stimulate the B-cells to
multiply and specialize into
plasma cells
• The plasma cells secretes
antibodies
28. The Nature of Antibodies
• Globular proteins called immunoglobulins
• Basic antibody structure has 4 polypeptide chains
– 2 identical light chains
– 2 identical heavy chains
• Regions of heavy and light chains
– Variable
– Constant
36. Types of Immunity
• Active Immunity
Natural active immunity - acquired due to infection
Artificial active immunity – vaccination
• Passive Immunity
Natural passive immunity
• placenta to the fetus
• Colostrum
Artificial passive immunity
• Injection of immune serum
Figure 43.17 The killing action of cytotoxic T cells on an infected host cell.
Figure 43.17 The killing action of cytotoxic T cells on an infected host cell.
Figure 43.17 The killing action of cytotoxic T cells on an infected host cell.
Figure 43.18 Activation of a B cell in the humoral immune response.
Figure 43.18 Activation of a B cell in the humoral immune response.
Figure 43.18 Activation of a B cell in the humoral immune response.
I. DEFINITION
Immunoglobulins (Ig) Glycoprotein molecules that are produced by plasma cells in response to an immunogen and which function as antibodies. The immunoglobulins derive their name from the finding that they migrate with globular proteins when antibody-containing serum is placed in an electrical field (Figure 1).
II. GENERAL FUNCTIONS OF IMMUNOGLOBULINS
A. Antigen binding Immunoglobulins bind specifically to one or a few closely related antigens. Each immunoglobulin actually binds to a specific antigenic determinant. Antigen binding by antibodies is the primary function of antibodies and can result in protection of the host. The valency of antibody refers to the number of antigenic determinants that an individual antibody molecule can bind. The valency of all antibodies is at least two and in some instances more.
B. Effector Functions Frequently the binding of an antibody to an antigen has no direct biological effect. Rather, the significant biological effects are a consequence of secondary "effector functions" of antibodies. The immunoglobulins mediate a variety of these effector functions. Usually the ability to carry out a particular effector function requires that the antibody bind to its antigen. Not every immunoglobulin will mediate all effector functions. Such effector functions include:
1. Fixation of complement - This results in lysis of cells and release of biologically active molecules (see chapter two)
2. Binding to various cell types - Phagocytic cells, lymphocytes, platelets, mast cells, and basophils have receptors that bind immunoglobulins. This binding can activate the cells to perform some function. Some immunoglobulins also bind to receptors on placental trophoblasts, which results in transfer of the immunoglobulin across the placenta. As a result, the transferred maternal antibodies provide immunity to the fetus and newborn
Immunoglobulin classes
IgM
First response to antigen
IgG
Most common form
IgA
Secreted form
IgD
B cell activation
IgE
Histamine reactions and allergies
