The document discusses T cell development, including their origin, maturation processes, and the distinctions between CD4 and CD8 T cells. It highlights the importance of positive and negative selection in the thymus and the role of major histocompatibility complex (MHC) molecules. Additionally, it outlines the functions of various cytokines in activating T cells and acknowledges the use of online resources for developing teaching materials.

1. Prof. Sreerama Krupanidhi
Email: sknbirac@gmail.com

2. T- cell development
09/02/24
Prof. Sreerama Krupanidhi
2

3. 1. To familiarize with T cells
2. To know the maturation of T
cells
3. To distinguish between Th and
Tc cells
4. To acquaint with the sites of T-
cells origin
5. To appreciate thymic schooling
09/02/24
Prof. Sreerama Krupanidhi
3

4. 1. The development of T cells
involving positive and negative
selection will be known.
2. MHC restricted development of
T cells in thymus will be
known.
09/02/24
Prof. Sreerama Krupanidhi
4

5.  Blood cell precursors originate
in yolk sac and liver
 In postnatal life, the stem cells
reside in the bone marrow
 Stem cells differentiate into
cells of erythroid, myeloid or
lymphoid series
09/02/24
Prof. Sreerama Krupanidhi
5

6. 09/02/24
Prof. Sreerama Krupanidhi
6

7. 09/02/24
Prof. Sreerama Krupanidhi
7

8. 09/02/24
Prof. Sreerama Krupanidhi
8

9. 09/02/24
Prof. Sreerama Krupanidhi
9

10. 09/02/24
Prof. Sreerama Krupanidhi
10

11.  Stem cells initially do not express CD4
and CD8 (Double Negative)
 Later they express both (Double Positive)
 Double positive cell will differentiate into
CD4 positive cell if it contacts a cell
bearing Class II MHC protein, but will
differentiate into CD8 positive cell if it
contacts a cell bearing Class I MHC
proteins
09/02/24
Prof. Sreerama Krupanidhi
11

12. Main Functions Cytokine Mediating That
Function
Activates the antigen
specific helper T cell to
produce a clone of these
cells.
IL-2
Activates cytotoxic T cells. IL-2
Activates B cells. IL-4 and IL-5
Activates Macrophages. Interferon Gamma
09/02/24
Prof. Sreerama Krupanidhi
12

13. 09/02/24
Prof. Sreerama Krupanidhi
13

14. 09/02/24
Prof. Sreerama Krupanidhi
14

15. 09/02/24
Prof. Sreerama Krupanidhi
15

16. 09/02/24
Prof. Sreerama Krupanidhi
16

17. 09/02/24
Prof. Sreerama Krupanidhi
17

18. 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
09/02/24 Prof. Sreerama Krupanidhi 18

19.  Blood cell precursors originate in yolk sac and
liver and transform to bone marrow during
postnatal life.
 Double negative T cells become double positive
naïve T cells
 T-cells undergo negative selection and positive
selection and develop as naïve Th and Tc cells.
 T cells development is MHC restricted.
 T cells are master Immune cells
09/02/24
Prof. Sreerama Krupanidhi
19

20.  Where from the name T came for T
cells?
 Indicate the CDs gradually added
to developing T cell.
 Elaborate on T cell differentiation.
 Explain Thymic schooling.
 What are CD4 and CD8?
 Explain Positive and Negative
Selection of T cells?
Study Questions
09/02/24
Prof. Sreerama Krupanidhi
20

21.  We acknowledge online
resources/public domains for
the use of the content to develop
teaching material.
Acknowledgements
09/02/24
Prof. Sreerama Krupanidhi
21

22. 09/02/24
22
Prof. Sreerama Krupanidhi