Lecture-5 Classification, attributes and functions of immune cells

Immune cells are generated from the bone marrow, short-lived and protects the host organism specifically against the target pathogen or illness.

1. 1 Lecture-5 Immune Cells Prof. Sreerama Krupanidhi Email: [email protected] 29-08-2024 Prof. Sreerama Krupanidhi

2. WHITE BLOOD CELLS SAFEGUARD OUR HEALTH 29-08-2024 Cytotoxic T Cell - Microbiology and immunology Animations.mp4 Prof. Sreerama Krupanidhi 2

3. Objectives To evaluate the attributes of Immune cells (WBCs). To Classify the function of immune cells. 29-08-2024 Prof. Sreerama Krupanidhi 3

4. Learning outcomes Types of WBCs and their attributes are known CDs of WBCs will be known CD8 T cells play a Role in graft (kidney) rejection Anti CD3 protects from rejection of grafted organs 29-08-2024 Prof. Sreerama Krupanidhi 4

5. White blood cells Definition: White blood cells are cells of the immune system which defend the body against both infectious diseases and foreign materials . 29-08-2024 Prof. Sreerama Krupanidhi 5

6. 29-08-2024 Prof. Sreerama Krupanidhi 6

7. Attributes of WBCs Boon to our health. Abnormality leads to severe disorders. Protect organs Protect tissues Intercommunicate through cytokines Produce and mature in lymph glands Amoeboid type Phagocytosis Endowed with Receptors to recognize PAMPS. Short lived Granulocytes involved in innate immunity. Lymphocytes (T & B) are involved in adaptive immunity. Clonal selection & proliferation Scope to engineer T cells 29-08-2024 Prof. Sreerama Krupanidhi 7

8. Name of WBCs 1. WBCs are found as white buffy coat , a thin layer of nucleated cells, between the sedimented red blood cells and the blood plasma in a dense Ficoll medium upon centrifugation at 1500 rpm. 2. The scientific term leukotyte directly reflects the description, derived from Greek leuko - white , and cyte - cell. 29-08-2024 8 Prof. Sreerama Krupanidhi

9. B Cell- CD 19, 20 Busa Fabricius / Bone marrow derived cells 29-08-2024 B cell activation.mp4 Prof. Sreerama Krupanidhi 9

10. The major function of B lymphocytes is to develop into antibody-secreting plasma cells. Antigen 29-08-2024 Prof. Sreerama Krupanidhi 10

11. T Cell- CD: 3, 4, 8 Lymphocytes mature in Thmus gland 29-08-2024 Prof. Sreerama Krupanidhi 11

12. They travel to the thymus gland, where they mature.   These divide into two major subsets. They are functionally and phenotypically different. T helper  ( Th ): Also called CD4+ T cells, involved in coordination and regulation of immunological responses. Th1 : anti-viral Th2: cell mediate immune response 29-08-2024 Prof. Sreerama Krupanidhi 12

13. Macrophage Fibroblasts Endothelial cells Stem cells Hematopoiesis Mast cell Eosinophil NK cell LAK cell Cytotoxic T cell T helper cell B cell Plasma cells Antibodies Neutrophil Inflammation 29-08-2024 Prof. Sreerama Krupanidhi 13

14. Tc Cells: These cells are involved directly in killing certain tumor cells, virus-infected cells, transplant cells, and sometimes eucaryotic parasites. Both types of T cells (Th & Tc) are found throughout the body. 29-08-2024 14 Prof. Sreerama Krupanidhi

15. NK Cell- CD 56 Effector function Non- effector function NK cell Corpuscle with self MHC-I ligand Corpuscle with missing self MHC-I ligand iKIR aR a. No-lysis b. Target cell lysis aL MHC-I 29-08-2024 Prof. Sreerama Krupanidhi 15

16.   NK cells directly kill certain tumors such as melanomas, lymphomas and virus-infected cells. NK cells unlike CD8+ (Tc) cells, kill their target cells without need for recognition of antigen in association with MHC molecules. NK cell kills the tumor cell deprived of self MHC molecules- the concept is known as Missing-self Hypothesis.    29-08-2024 Prof. Sreerama Krupanidhi 16

17. Neutrophils CD 45 29-08-2024 Prof. Sreerama Krupanidhi 17

18. Neutrophils are the first immune cells to arrive at a site of infection, through a process known as chemotaxis. Neutrophil extracellular trap (NET), traps and kills microbes outside of the cell. 29-08-2024 Prof. Sreerama Krupanidhi 18

19. Eosinophil CD 34 and CD 11b 29-08-2024 Prof. Sreerama Krupanidhi 19

20. Eosinophils cause allergies and other inflammatory reactions in the body . These are part of the innate immune system. 29-08-2024 Prof. Sreerama Krupanidhi 20

21. Basophils CD 33, CD 36 29-08-2024 Prof. Sreerama Krupanidhi 21

22. Basophils appear in inflammatory reactions, particularly cause allergy. They are found in tissues where allergic reactions are occurring. Basophils have protein receptors on their cell surface that bind  IgE . 29-08-2024 Prof. Sreerama Krupanidhi 22

23. Mast cells CD 117 23 29-08-2024 Prof. Sreerama Krupanidhi

24. Mast cell mediate   inflammatory responses (Attributes of inflammation: Red, heat, swelling and pain) such as hypersensitivity and allergic reactions. It is rich in histamine and heparin. 29-08-2024 Prof. Sreerama Krupanidhi 24

25. Monocytes 29-08-2024 Prof. Sreerama Krupanidhi 25 Pseudopodial extension Of resident monocyte Chasing the bacteria is Seen.

26. Monocytes are large, agranular leukocytes with relatively small, eccentric, oval or kidney-shaped nuclei. Monocytes are of two types Macrophages CD 14 Dendritic cells CD 141 29-08-2024 Prof. Sreerama Krupanidhi 26

27. Macrophages: antigen-presenting cells (APCs) This is one of the important first steps in the initiation of an immunological response. 29-08-2024 Prof. Sreerama Krupanidhi 27

28. 29-08-2024 Prof. Sreerama Krupanidhi 28

29. Cells involved in innate and adaptive immunity 29-08-2024 Prof. Sreerama Krupanidhi 29

30. Summary WBCs are Lymphocytes and Leukocytes. They are Immunocompetent and Immune accessary cells. WBCs are varied types with distinct functions. WBCs count determines the state of health. WBCs secrete cytokines and B cell bales out IgGs. WBCs converse and execute. CD4 T cells are vulnerable to HIV infection CD8 T cells promote graft rejection Anti CD3 depletes T cell population and promotes graft acceptance and tolerance. T cells are engineered as CAR T cells for blood cancer therapy. 29-08-2024 30 Prof. Sreerama Krupanidhi

31. Study Questions What are the attributes of WBCs? How do organisms get protected? Which immune cells are invovled in adaptive immunity? Which immune cell is classified as the best antigen presenter? Indicate the differential role of WBCs while infiltrating at the site of infection/inflammation. Enlist CDs of at least 5 WBCs. Mention one of the significant steps in the initiation of immune response. 29-08-2024 Prof. Sreerama Krupanidhi 31

32. Acknowledgements 29-08-2024 32 We acknowledge the online resources and public domains for the Preparation of the content to develop teaching material and for the dissemination of knowledge. Prof. Sreerama Krupanidhi

33. Thank you 29-08-2024 Prof. Sreerama Krupanidhi 33