IMM2011 Lecture Notes - Lecture 10: Transplant Rejection, T Cell, Antigen Processing
23 Jun 2018
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LECTURE : 10 and 11: MHC MOLECULE
Major histocompatibility complex:
Membrane bound protein that function to show activate t cell by
displaying antigen to it.
Describe the structure of MHC class I and MHC CLASS II:
MHC class 1
Contains two chains , in which and
alpha chain in noncovalently
associated with a protein called b2
microglobulin.,
Alpha chain contains three
extracellular domain: which is
followed by short transmembrane
and cytoplasmic domain.
Alpha 1 and 2 domain: form peptide
binding cleft
- Cleft flow: binds peptide
- Cleft wall: contacts TCR
ALPHA 3 domain: binds CD8 t cell co receptor.
Disulfide bonds: hold the structure together
MHC CLASS II:
On other hand MHC class 2:
also has two
transmembrane chains
- Polymorphic alpha
chain
- Polymorphic b chain
Each of these has two
extracellular domain ,
followed by transmembrane
and cytoplasmic regions.
Alpha 1 and beta 1 domain:
- Form the peptide binding cleft
Non polymorphic a2 and b2 domain:
- Binds cd4 T cell co receptor
Learning objective 3: Compare and contrast MHC class I and class
II processing, highlighting similarities and differences
Similarities:
- MHC have broad specifiity : in which many different petides acan
bind to the same mhc molecule
- Both can bind only on peptide at each time
- Binding to peptide is for long time so T cell can have time to
interact with peptide
- MHC STABLE: when peptides bound
-
Differences:
1) Mhc 1 : found on all nucleated cell and MHC class II found on APC
(DC, macrophages and b cell, endothelial cell and thymic
epithelial cell.
Document Summary
Membrane bound protein that function to show activate t cell by displaying antigen to it. Describe the structure of mhc class i and mhc class ii: Contains two chains , in which and alpha chain in noncovalently associated with a protein called b2 microglobulin. , Alpha chain contains three extracellular domain: which is followed by short transmembrane and cytoplasmic domain. Alpha 1 and 2 domain: form peptide binding cleft. Alpha 3 domain: binds cd8 t cell co receptor. On other hand mhc class 2: also has two transmembrane chains. Each of these has two extracellular domain , followed by transmembrane and cytoplasmic regions. Learning objective 3: compare and contrast mhc class i and class. Mhc have broad specifiity : in which many different petides acan bind to the same mhc molecule. Both can bind only on peptide at each time. Binding to peptide is for long time so t cell can have time to interact with peptide.
