Merges 2022 Result_2024_03_13_07_21_45.pptx

Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiology Immunology Microbiolog

1. Government Medical College and Super Facility Hospital, Azamgarh T CELL B CELL AND THEIR ACTIVATION Presented by: Awanish Yadav (21) Ayushi Chaudhary (22) Ayushi Kaushik (23) Chandan Gupta (24) Guided by: Dr. Pratiksha Srivastava Dr. Preeti Kumari

2. B Cell Development  Maturation - Stem cells to mature, naïve B cells  Activation - Ag binding; initiation of cell changes  Differentiation - Cell division and changes into effector B cells (plasma cells) and memory B cells

3. Lymphopoiesis Occurs in yolk sac, fetal liver then bone marrow throughout rest of life Mature, naïve B cells released into circulation B cell production occurs throughout life; does not wane as does T cell production About 5 million produced per day Only 10% of B cells mature Naïve B cells survive about one week Undergo negative selection

4. B Cell Maturation Hematopoietic stem cells(HSC) Lymphoid stem cell (progenitor) B cell progenitor (pro- B cell) Pre- B cell Immature B cell Mature, naïve B cell

5. B Cell Changes Pro B cells Rearrangement of Ig heavy chain genes (D to J joining followed by V to DJ) Not all rearrangements result in complete mu variable region sequences Expression of CD45R and CD19 Further maturation is dependent on direct interaction with BM stromal cells c- Kit on pro B is activated by SCF on stromal cells

6. B Cell Changes Pre B cells Cell division occurs Rearrangement of Ig light chain genes (V to J joining) Expression of IL7 receptor Expression of mu heavy chains in association with Ig alpha - Ig beta heterodimer Pre B cell receptor uses surrogate light chains Shuts down further Ig gene rearrangement

7. B Cell Changes Immature B cells IgM expressed on surface B cell receptor appears Cells interact with self Ags Negative selection (clonal deletion) occurs

8. B Cell Changes Mature B cells Migrate out of bone marrow Both IgM and IgD expressed on surface Cell division occurs Rearrangement of Ig light chain genes (V to J joining) Expression of IL7 receptor Expression of mu heavy chains in association with Ig alpha - Ig beta heterodimer Pre B cell receptor uses surrogate light chains Shuts down further Ig gene rearrangement

9. Cell- Mediated Immunity T cells constitute 70–80% of blood lymphocytes. They are responsible for Cell Mediated Immunity. Unlike B cells, they do not have microvilli on their surface. They bear specialized surface receptors called T cell receptors (TCR) T CELLS

10. T Cell- mediated Immunity  Principal function - Response to intracellular pathogens and cells expressing foreign antigens  Recirculation - Naïve T cells circulate between the blood stream and the lymphatic system  Antigen presentation - Naïve T cell cells only respond to APCs

11. T CELL RECEPTOR (TCR) Their main function is antigen recognition. It can only respond to an antigen which is processed and presented by the antigen presenting cells, such as macrophages. About 5% of TCRs do not have α/β chains, instead they bear γ/δ chains. Most T cell receptors (95%) comprise of two chains (α and β) which in turn have three regions— extracellular domain, trans membrane domain (3) cytoplasmic

12. TCR – CD3 COMPLEX The CD3 complex consists of three pairs of polypeptide chains—ξξ (zeta-homodimer), δε (delta–epsilon heterodimer) and γε (gamma–epsilon heterodimer) ™ Following binding of antigen to α and β chains of TCR, a signal is generated that is transmitted through the CD3 complex leading to activation of T cells

13. T cells have : CD 1,2,3,4,5,6,7,8,28,40 The pan T cell marker is CD3 CD3 is going to take signal transduction molecules CD Marker Of T CELL

14. T – CELL DEVELOPMNET

15. TYPES OF T CELLS There are two types of effector T cells CD4+ helper T cells (2) CD8+ cytotoxic T cell. ™ Helper T cells: Helper T cells (TH) possess CD4 molecules as surface receptors. They recognize the antigenic

16. DIFFERENCE BETWEEN T CELLS AND B CELLS

17. Priming of T Cells Three types of effector T cells CD8 (T C ) CD4 (T H1 ) CD4 (T H2 ) Each type Responds to different types of Ags Activated by different Ag presentation Has different effector function

18. T Cell Effector Types CD8 Viruses and intracellular bacteria MHC I Cytotoxic effector cells CD4 T H1 Bacteria and parasites in APCs MHC II Effectors activate macrophages, CTLs and induce B cells to produce opsonins CD4 T H2 Extracellular bacteria and toxin producers MHC II Activate B cells to produce multiple antibody classes

19. Antibody- Dependent Cell- Mediated Cytotoxicity NK cells, macrophages, neutrophils Bind to Fc region of Ab Multiple cytotoxic mechanisms

20. These cell has the B cell receptor with IgM and IgD B CELL

21. B cells have : CD 10,19,20,21,22,23,40,79a,79b The pan B cell marker is CD19 CD 79a,79b is going to take signal transduction molecules CD Marker Of B CELL

22. Bcells have IgM and IgD IgM and IgD are converted in IgA, IgG , IgM , IgD , IgE by isotype switching B cell has CD 40 Receptor T cell have CD 40 Ligand INTRACTION BETWEEN B CELL AND T CELL

23. When a foreign body(antigen) enter into the body then it attach to IgM antibody Then this B cell give antigen to T Cell T cell generate IL 4 IL4 convert IgM and IgD are in IgA, IgG , IgM , IgD , IgE by isotype switching

24. Formation of antibody is generally considered as Humoral Immunity IgG IgA IgM IgD IgE

25. ANTIGEN PRESENTING CELL It is divided into two parts 1-Professional APCs Dendritic cell B cell Macrophages 2- Non-Professional APCs Thymic Epithelial Cells Endothelial Cells Fibroblasts

26. Major Histocompatibility Complex It is originated from HLA gene that is presented on the chromosome 6p Short arm Chromosome 6 HLA gene HFE gene

27. STRUCTURE OF HLA GENE It has many part HLA Gene I HLA Gene II HLA Gene III HLA Gene I has HLA IA HLA IB HLA IAC HLA IE and HLA IG HLA Gene II has DP,DQ,DR HLA Gene III has no sub division

28. STRUCTURE OF HLA GENE HLA Gene I – MHC I HLA Gene II – MHC II

29. Difference Between MHC I and MHC II

30. Type of T Helper cell

31. Mechanisms Of Cytotoxic Cells

32. BIBLIOGRAPHY Essential of Medical Microbiology by Apurba S Sastry and Sandhya bhat (4 th Edition) Textbook of Microbiology by Ananthanarayan and Paniker’s (12 th Edition)

33. THANK YOU