1. and CHAPTER 6 Major Histocompatibility Complex (MHC) Molecules
Antigen Presentation to T Lymphocytes

3. Principal functions of T lymphocytes are defense against intracellular microbes and activation of other cells, such as macrophages and B lymphocytes
All these functions require that T lymphocytes interact with other cells
Task of displaying cell-associated antigens for recognition by T cells is performed by specialized proteins that are encoded by genes in a locus called the Major Histocompatibility Complex (MHC)

5. Features of Antigens Recognized by T Lymphocytes

6. PROPERTIES OF ANTIGENS RECOGNIZED BY T LYMPHOCYTES
Physiologic function of MHC molecules is the presentation of peptides to T cells
There are two main types of MHC gene products, called class I MHC (present peptides to CD8+ CTLs) molecules and class II MHC (present to CD4+ helper T cells) molecules

7. T cell Recognition of a Peptide-MHC Complex

8. Functions of different antigen-presenting cells

10. Routes of Antigen Entry

13. Role of dendritic cells in antigen capture and presentation

14. THE MAJOR HISTOCOMPATIBILITY COMPLEX (MHC)
Discovery of the Human MHC

15. The Mouse MHC (H-2 Complex)
The genetic region that controlled graft rejection and contained several linked genes was named the major histocompatibility complex (MHC)
Human MHC or Human leukocyte antigens (HLA)
Immune response (Ir) genes

16. MHC Genes

18. Map of the human MHC

19. Expression of MHC Molecules

20. MHC Molecules

24. PROCESSING OF PROTEIN ANTIGENS

27. The class I MHC pathway of antigen presentation

28. The class II MHC pathway of antigen presentation

30. Cross-presentation of antigens to CD8+ T cells

32. Presentation of extracellular and cytosolic antigens to different subsets of T cells

33. PRESENTATION OF NONPROTEIN ANTIGENS TO SUBSETS OF T CELLS
The best defined of these populations are NKT cells and γδ T cells
NKT cells express markers that are characteristic of both natural killer (NK) cells and T lymphocytes and express αβ T cell receptors with very limited diversity
Class I–like “non-classical” MHC molecule called CD1
γδ T cells recognize many different types of antigens, including some proteins and lipids, as well as small phosphorylated molecules and alkyl amines