细胞免疫主要组织相容性复合体.pptVIP

The CD1 family present microbial lipids to CD1-restricted T cells CD1 Human, CD1a, b, c, d, e; Mouse , CD1d1, CD1d2 Encoded outside the MHC region looks like MHC I(β2m) Behaves like MHCII, binds its ligand in vesicles instead of ER Have a hydrophobic binding groove Present a variety of lipids Group 1, CD1a, b, c; Presents mycolic acid, lipoarabinomannan to αβ T cells Group 2, CD1d; Presents sphingolipids, diacylglycerols, α-Galactoceramide (α-GalCer) to NKT cells CD1d presents glycolipids to NKT cells Summary MHC Introduction Discovery MHC gene structure Expression MHC polymorphism and polygeny Molecular structure, binding of peptides to MHC molecules, MHC restriction Non-classical MHC molecules A variety of genes with specialized functions in immunity are also encoded in the MHC MHC class Ib genes—Structure is closely related to class I Mouse H2-M3 present peptides with N-formylated amino termini T22 and T10 regulate γδT cells HLA-H (HFE)– iron metabolism MICA, MICB CD1 MHC class III region: complement, TNF, LT Summary MHC class I and class II proteins present peptides to TCRs. MHC restriction Polymorphism and polygeny Non-classical (Class Ib) MHC CD1d MHC functions Present antigenic peptides to T cells Immune regulation NK cells (missing self) Pregnancy (suppressive) T cell development Mucosal immunity Non-immune functions Regulation of MHC expression IFN-α, IFN-β, IFN-γ?MHCI IFN-γ?MHCII CIITA (ClassII transcription activator) TAP, immuno-proteasome subunits MHC Polymorphism and Polygeny MHC Polymorphism and Polygeny Polymorphism: Multiple variants within a population Heterozygous for MHC genes Co-dominantly expressed Polygeny: MHC contains several different class I and class II genes Every individual has a set of MHC molecules with different ranges of peptide-binding specificity MHC Polymorphism MHC Class I Polymorphism MHC polymorphism extends the range of antigens to which the immune system can respond MHC, 20 AA difference; others, one or a few Evasiv