Antigen Recognition by T Lymphocytes

1. Antigen Recognition by T Lymphocytes

4. T Cell-Antigen Recognition Respond to contiguous short amino acid sequences in proteins-T Cell Epitopes Peptides Not Native Protein T cells do not bind free peptides T Cells Recognize a complex of a peptide fragment bound to the membrane proteins of cells- Major histocompatibility complex (MHC) molecules

6. MHC Molecules MHC I MHC II Physiological function is to present peptides to T cells

7. Major Histocompatibility Complex Proteins Human-HLA (human leukocyte antigen) Mouse: H-2 Bovines: BoLA Equines: ELA Swine: SLA OLA, CLA, DLA, FLA

9. MHC Class I Molecules

10. MHC Class I Molecules Present Peptides to CD8+ T Cells Expressed on ALL Nucleated Cells of the Body

15. MHC Class II Molecules

16. MHC Class II Molecules Present Peptides to CD4+ T Cells Expressed on Dendritic Cells, B Cells, Macrophages-Professional Antigen Presenting Cells

21. General Characteristic of Peptide-MHC Interactions Each MHC class I & class II molecule has a single peptide binding cleft that can bind many different peptides Anchor Residues

23. Two different Peptides bind the same MHC Sequence Motif

26. MHC Polymorphism

31. Self MHC Restriction

32. Both CD4+ and CD8+ T cells can recognize antigen only when presented by a self-MHC molecule on the membrane of an antigen presenting cellsCD4+ T Cells-Self MHC II-RestrictedCD8+ T Cells-Self MHC I-Restricted

36. T Cell Subsets