The document provides an overview of T lymphocytes, detailing their origin, functional roles in cell-mediated immunity, and differentiation processes that occur in the thymus. It discusses the emergence of T cell subsets, specific surface markers, and T cell receptors that are crucial for their function. Additionally, it covers the interplay between T and B cells within the immune response.

1. Immunology

2. T Lymphocytes

3. T Cells
Introduction
 Tymus derived T lymphocytes
 Effectors and regulatory response
 Function of T cells
 Cytotoxic, suppression and killer property

4. T Cells
T Cell origin
 Start from multipotent stem cell
 From bone marrow to thymus
 Epithelium stroma and sponge contains
lymphocytes
Migrates to blood stream

5. Immunological function of
Thymus
 Production of T cells
 T cells are involved in cell mediated
immunity
 T cell cannot produces antibodies
 Thymic hormones

6. Immunological function of
Thymus
 Production of T cells
 T cells are involved in cell mediated
immunity
 T cell cannot produces antibodies

7. Immunological function of
Thymus
 Thymic extract – thymosin – induce
differentiation
 Self reactive – Purine deoxynucleotides
 Non self reactive - MHC antigen
Multipotent
cell
Pre T
Cell
Thymus
T helper Cell
Cytotoxic T Cell
Supressor T Cell
Delayed Hypersensitivity T Cell

8. Immunological function of
Thymus
Emergence of T cell Subset
 Thymus - Spleen – Blood –Lymphoid system
 T helper Cells THF
 Cytotoxic T cells TcF
 Suppressor - inducer T cells Ts
Delayed hypersensitivity T cells TDH

9. Immunological function of
Thymus
 Thymic extract – thymosin – induce
differentiation
 Self reactive – Purine deoxynucleotides
 Non self reactive - MHC antigen
Multipotent
cell
Pre T
Cell
Thymus
T helper Cell
Cytotoxic T Cell
Supressor T Cell
Delayed Hypersensitivity T Cell

10. Immunological function of
Thymus

11. Immunological function of
Thymus
Surface marker of T lymphocytes
Stem cells (Thymus

12. Surface marker of T
lymphocytes
Surface marker of T lymphocytes
 Displaying of surface markers
 Markers are glycoprotein coded by MHC
genes
 Identify T cell subset and their function

13. Surface marker of T
lymphocytes
 Thy 1 in mouse
 Marker on T cell bind with sheep erythrocytes
 First CD2 CD4, CD5 and CD8 are
expressed
 CD4 and CD8 appears

14. T cell receptors
 Antigen specific receptors
 α – β disulphide bonds
 CD2 – sheep red cells
 CD3 – stabilize cell
 CD4 –MHC class II
 CD8 – MHC class I

15. T cell receptors
 Antigen specific receptors
 α – β disulphide bonds
 CD2 – sheep red cells
 CD3 – stabilize cell
 CD4 –MHC class II
 CD8 – MHC class I

16. Surface marker of T
lymphocytes

17. T cell receptors
 Receptor is heterodimer
 α and β chain linked with disulphide bond
 Sheep erythrocyte and CD2
 CD3 molecules – stabilize T cell
 CD4 and CD8 with MHC class I and II

18. Function of T subset
 Tc cell – Lymphotoxins
 Activating signals IL1 and IL2
 TH cells
 MHC class I and II
 Ts cell
 TDH
Inducer of help
Inducer of suppression

19. T cell Activation

20. T cell Factors
 Antigen specific factor
 Antigen independent factor
Cooperation between T and B cells