CLASS immunity Physiology mbbs 1st year _

This is A physiological presentation very good

1. IMMUNITY Dr.PRAVEENA MD.PHYSIOLOGY

2. , MALT

3. BONE MARROW B lymphocytes – formation, multiplication ,maturation T lymphocytes – formation , multiplication THYMUS T lymphocyte – maturation/ development Lymp . Stem cell NK CELL

4. THYMUS GLAND Bilobed endocrine gland Located in sup.mediastinum , infront of the heart, behind sternum. Size decrease with age .

5. Thymectomy for Rx of myasthenia gravis

6. Lymphadenopathy Indicates infection of that area which it drains

7. - TONSILS -APPENDIX -PAYER’S PATCHES (GIT) -MALT

8. . GALT   ( gut associated lymphatic tissue   BALT  ( bronchus-associated lymphoid tissue ) NALT  ( nasal-associated lymphoid tissue ) CALT  (conjunctival-associated lymphoid tissue) LALT  (larynx-associated lymphoid tissue) SALT  (skin-associated lymphoid tissue) VALT  ( vulvo -vaginal-associated lymphoid tissue) TALT  (testis-associated lymphoid tissue)

9. Immunity Def: capability of the body defense mechanism to resist the actions of microorganisms .

10. BARRIER PROTECTION INNATE IMMUNITY ADAPTIVE/ACQUIRED IMMUNITY MECHANICAL & CHEMICAL BARRIERS PHAGOCYTIC CELLS & NK cells B & T lymphocytes

11. Sabaceous secretions , Saliva , Urine , feces

12. BARRIER PROTECTION INNATE IMMUNITY ADAPTIVE/ACQUIRED IMMUNITY MECHANICAL & CHEMICAL BARRIERS PHAGOCYTIC CELLS & NK cells B & T lymphocytes

13. Innate immunity Features: - present BY-BIRTH - non-specific - no memory - less potent ( than acquired immunity ) ( b’coz its less specialized )

14. 1. Immunity by Phagocytic cells:

15. LT- B4, C5a, C3

16. 2. Defense by inflammation & fever INFLAMMATION : the reaction of tissues to infection is called inflammation. Vasodilation & increased permeability Phagocyte migration & Phagocytosis Tissue repair

17. Acute phase proteins: produced during inflammation by the liver. CRP : C reactive protein Haptoglobulin Fibrinogen cause fever C3 complement protein

18. Fever is a protective response of the body . (high temperature prevent the growth of microorganisms, increase action of interferons & enzymes) So, unless its very high, fever should not be brought down by anti- pyretics !!!!!

19. 3. Defense by NK cells

20. BONE MARROW B lymphocytes – formation, multiplication ,maturation T lymphocytes – formation , multiplication THYMUS T lymphocyte – maturation/ development Lymp . Stem cell NK CELL

21. NK cell : natural killer cell  NK cells are unique, however, as they have the ability to recognize and kill stressed cells in the absence of MHC , allowing for a much faster immune reaction. Help in innate immunity.

22. Antibody mediated destruction of cell : NK cells recognize the Fc portion of antibody Release interferon ϒ which activates macrophages and causes phagocytosis

23. MISSING-SELF HYPOTHESIS : Differentiating b/w self & non-self cells by the presence / absence of INHIBITORY RECEPTORS. - Cancer cell - Virus infctd.cell

24. NK cells can be identified by the presence of  CD56  and the absence of  CD3  

25. 4.Defense by Complement system

26. COMPLEMENT SYSTEM

27. - Complementary proteins (C1-9) are synthesized in liver. - They also exhibit DIAPEDISIS.

28. C3 C5 C3a C3b C5a C5b

29. C3a : CHEMOTAXIN C5a: CHEMOTAXIN C3b: OPSONIN MAC: C5b,C6,C7,C8,C9 CLASSIC PATHWAY Activated by Ag-Ab rection Initiated by C1

30. MAC : membrane attack complex

31. C3a : CHEMOTAXIN C5a: CHEMOTAXIN C3b: OPSONIN MAC: C5b,C6,C7,C8,C9 ALTERNATE PATHWAY - Initiated by C3 - Does not involve Ag-Ab complex

32. TOLL - LIKE RECEPTORS

33. 5. Defense by dendritic cell : Connects INNATE IMMUNE SYSTEM & ADAPTIVE IMMUNE SYSTEM They identify the pathogen & give them to the adaptive immune system They are APC Cells (antigen presenting cell)

34. Homework - Lewi’s TRIPLE RESPONSE

35. ACQUIRED / ADAPTIVE IMMUNITY Dr.PRAVEENA MD.PHYSIOLOGY

36. MHC complex Histocompatibility refers to the antigens present on the plasma membrane of cells of each individual of species. These antigens are encoded by genes known as histocompatibility genes collectively known as MHC (major histocompatibility complex)

37. They are known as human leucocyte antigen (HLA) because they are present on the surface of leucocytes.

38. HLA genes are located on short arm of chr.6

39. No two individuals are except identical twins have the same MHC proteins on their cell membranes.

40. MHC I : are found on surface of all cells MHC II : are found on APC ( B lymphocytes, macrophages, monocytes, dendritic cells )

41. STEPS OF ANTIGEN PRESENTATION There are five major steps in antigen presentation: Ingestion of antigens, Digestion of antigen, Fusion of vesicles, Binding of peptide fragments to MHC molecule, and Incorporation of antigen-MHC complex into the cell membrane of APC.

42. Uses of HLA typing : To determine HLA compatibility prior to organ/tissue transplantation from one individual to another within a species For paternity testing For anthropological testing For establishing HLA disease association

43. Immunological synapse

44. T cells differentiation

45. STEPS OF CELLULAR IMMUNITY Mechanism of cellular immunity includes following steps: Antigen recognition, processing and presentation Activation and proliferation of T cells Elimination of the invader

46. APC include MACROPHAGES , DENDRITIC CELLS , B-LYMPHOCYTES

47. Normally, B cell activation does not depend on presentation of antigen by APCs. Antigens can directly stimulate B cells. However, antigens on the surface of APCs also activate B cells HUMORAL IMMUNITY

48. STEPS OF HUMORAL IMMUNITY Activation of humoral immunity involves six steps: 1. Presentation of antigen 2. Activation of B cells 3. Differentiation of B cells into plasma cells 4. Proliferation of plasma cells and antibody production 5. Killing of the invaders by antibodies that include activation of complement system 6. Formation of memory B cells and subsequent immunological responses

49. Blast transformation ( Plasmoblast )

50. 1. Neutralizing antigen: 2. Immobilization of microbes:   3. Activation of complement system:   4. Precipitation of antigens: 5. Facilitation of phagocytosis:   ​

51. TYPES OF HUMORAL IMMUNE RESPONSES There are two types of immune responses: The Primary response The Secondary response

52. Transplant rejection is due to the activation of cellular immunity. The immune system recognizes the transplanted tissue as a foreign organ and initiates a series of immunological reactions that finally rejects the tissue. The rapidity at which the transplanted tissue is rejected depends on degree of matching of MHC antigen (HLA antigen) of donor with the HLA antigen of the recipients.