Immunology

Question 1

WHAT IS MHC

Answer 1

A complex set of genes inherited as a unit that codes both MHC class 1&c lass2

Question 2

Difference between MHC 1 & 2

Answer 2

Question 3

Difference between MHC 1 & 2
MHC class 1- beta-2> CD8 co receptor > CD8+ cells
MCH class 2- beta 1&2- CD4 co receptor > CD4+ T cell

Answer 3

MHC class 1 bind to protein/antigen and display them to the cell surface.
1. MHC class 1- expressed on all nucleated/platelets and not RBC in association with a small invariant peptide bound to MHC class 1 interacts with the TCR of the CD8+ T cell.
2. Main functions are to kill pathogen infected host cell, tumors and transplants tissues. Interact with molecules expressed on NK cells (preventing NK cells killing normal cells.
3. MHC class 2-expresed constitutively only cells that present antigens on T cellssuch as dendritic cells, macrophages and B cells. Interacts on cell surface of TCR with of TCD4+ T cells.

Question 4

What is an antigen receptor

Answer 4

BCRs and TCRs are made in humans

Various gene segments encode for each receptor chain.
For B and T cells it involves VDJ recombination
V - Variable gene segments
D – Diversity gene segments
J – Joining gene segments
VDJ JOINING

Each V, D and J gene segments has a Recombination
Signal Sequence (RSS) attached:
 At the 3 end of each V  At both ends of each D  At the 3 end of each J
RSS is recognised by Recombination Activating Genes 1
and 2 (RAG-1 & RAG-2), identifying where gene splicing
will be occurring to form the finished heavy chain.
D and J joins first followed by the DJ combined segment
binding to the V segment
Diversity is increased by
Imprecise splicing between VH and DH and DH and JH
Extra nucleotides, N regions, can be randomly inserted

Question 5

BCR
HEAVY CHAIN

B\

Answer 5

FOUND ON CHROMOSOME 14