1. Self-MHC restriction of the T cell receptor

2. Self-MHC restriction of T C cells R. Zinkernagel & P. Doherty

3. Cloning of the TCR  -chain gene by subtractive hybridization By S. M. Hedrick & M. M. Davis

4. 3 important assumptions made by Hedrick and Davis: The TCR mRNA would be associated with membrane- bound polyribosomes like the mRNAs that encode other integral membrane proteins. (eliminate ~97% mRNAs) 98% of the genes expressed in lymphocytes are common to B and T cells. TCR should be in the 2% genes expressed specifically in T cells. (DNA subtractive hybridyzation eliminates 98%) TCR genes should undergo DNA rearrangements like those observed in the Ig genes of B cells.

7. Structure of the  T-cell receptor and surface IgM

8. Difference in the structures of the  and  receptors

9. Limited diversity

10. Organization of mouse TCR gene segments A productive rearrangement of the  chain gene segments deletes C 

12. TCR variable- region genes rearrange in a manner similar to Ig gene

13. Junctional diversity

16. The CDR3 of the TCR has greater diversity than that seen in immunoglobulins

17. T-Cell Receptor Complex: TCR-CD3 CD3 is required for membrane expression of T cell receptors or ζη

19. Structures of the CD4 and CD8 coreceptors or  dimer

20. CD8 binds to class I by contacting MHC class I  2 and  3 domains

21. CD4 binds to class II through MHC class II  2 and  2 domains

22. Affinity of TCR for peptide-MHC complexes is weak compared with antibody binding T cell-APC interactions are strengthened by cell-adhesion molecules, including CD2, LFA-1, CD28, and CD45R

23. Role of coreceptors in TCR binding affinity

25. The ternary complex Of mouse TCR Bound to MHC Class I and peptide CDR3

26. MHC molecule viewed from above not in contact with peptide

27. CDR regions of mouse TCR  and  chains viewed from above

28. TCRs interact differently with class I and class II moleucles

29. Alloreactivity of T cells: in addition to self-MHC plus antigens, T cells also respond to foreign MHC molecules, a reaction that leads to rejection of allogeneic grafts (transplants in the same species) Alloantigens: epitopes present on molecules that differ among members of the same species because of genetic variation. T cells recognize a foreign MHC molecules directly. ~1-5% of all T cells are reactive to alloantigen.