T Cell Receptors and MHC Flashcards
Gene responsible for somatic recombination of gene segments that encode antigen receptors:
Recombinase Activating Gene (RAG).
Multivalent immune response:
Immune response generated against multiple epitopes.
MHC restriction:
T cell receptor binds to both the peptide and the MHC molecule.
MHC encodes:
Human Leukocyte Antigens (HLA).
MHC is found on chromosome:
Chromosome 6.
Antigen presenting genes in class I HLA:
HLA-A, HLA-B, HLA-C
Antigen presenting genes in class II HLA:
HLA-DP, HLA-DQ, HLA-DR
MHC class I binds peptides from:
Intracellular pathogens and self proteins.
- Presented to CD8 T cell.
MCH class II binds peptides from:
Extracellular pathogens.
- Presented to CD4 T cell.
Antigen presenting cells express:
MHC class I and II simultaneously.
Binding groove of MHC class I:
8-10 aa in length.
Binding groove of MHC class II:
8-25 aa in length.
- Bigger, more permissive.
Anchor peptides:
Only certain aa residues in the peptide binding groove are critical for a peptide to bind to an HLA molecule.
MHC Class I and II proteins can be up-regulated by:
Cytokines INF-gamma and TNF.
Antigen processing:
Intracellular degradation of protein antigens into peptides, which are then bound to MHC molecules.
Breaks down pathogen proteins for presentation:
Immunoproteasome.
Invariant chain:
Blocks binding of peptides to MHC class II molecules in the ER.
Facilitates release of CLIP, allowing peptides to bind MHC class II:
HLA-DM
B cells present:
Extracellular antigens via HMC class II molecules. - Utilize surface immunoglobulin to capture antigen.
