Download Major Histocompatibility complex OR

Major Histocompatibility
complex
OR
MHC
‫تفاوت آنتي ژنهاي سازگاري‬
‫ساختمانی‬
‫ژنی‬
‫توزیع سلولی‬
‫معرفی نوع پپتید‬
‫سلول شناسایی کننده‬
MHC

The principal function of T cells are :
Defense against intracellular microbes
Activation of other cells(B cells ,Macrophages )

peptide recognition by T and B cells is
different.
B cells recognize soluble as well as cell associated Ags
In contrast ,T cells recognize peptide which is displaying only
by APC in associated with MHC proteins.
MHC





MHC genes are the most polymorphic genes
MHC genes are codominantly expressed in each
individual
There are two main type of MHC:class I & II
The physiologic function of MHC molecules is
presentation of peptides to T cells ,control of
immune responsiveness to all proteins and graft
rejection
MHC-I present cytosolic peptides to T cytotoxic
cells and MHC-II present endocytosed peptides
to Th cells
MHC –I structure
MHC-II structure
T cell receptor and MHC
interaction
Polymorphism of class II





HLA-DPA
HLA-DPB
HLA-DQA
HLA-DQB
HLA-DR
12
88
17
42
>400
POLYMORPHISM OF MHC PROTEINS
DR
1
HLA-A >280
DR >400
HLA-B >500
DQ >50
HLA-C >130
Variability is in the amino acid residues in the peptide binding
site!