Major Histocompatibility complex OR

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Major Histocompatibility complexOR

• MHC

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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.

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MHC

• MHC genes are the most polymorphic genes
• MHC genes are codominantly expressed in each
  individual
• There are two main type of MHCclass 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

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MHC genes
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MHC I structure
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MHC-II structure
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T cell receptor and MHC interaction
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Polymorphism of class II

• HLA-DPA 12
• HLA-DPB 88
• HLA-DQA 17
• HLA-DQB 42
• HLA-DR gt400

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Polymorphism of class I

• HLA-A gt280
• HLA-B gt500
• HLA-C gt130

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MHC genes and graft rejection
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HLA expression
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Peptide presentation by MHC-II
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Peptide presentation by MHC-I