Major Histocompatibility complex (MHC): Introduction, Types and Differences
- Types of Major Histocompatibility complex (MHC)
- Difference between Type 1 and Type 2
- MHC products play an important role in intracellular recognition and discrimination between self and non self.
- MHC participates in development of humoral and cellular immune responses.
One chromosome pair coding for three different classes of protein:
- Class 1 Protein that determined histocompatibility and the acceptance or rejection of allograft.
- Class 2 Protein that regulate the immune response.
- Class 3 Protein that include some components of the complement system and a few others.
- HLA (Human Leucocyte antigens) complex: The HLA complex of genes is located on the short arm of chromosome 6.
- It consists of three separate cluster of:
- HLA class 1 comprising A, B and C loci.
- HLA or D region consists of DR, DQ, and DP loci.
- Class3 or the complement reason containing genes for complement component C4B, BFC2 to TNF.
Type of major Histocompatibility complex
- MHC type 1
- MHC type 2
- MHC type 3
MHC type 1
- The gene of this MHC is Coat glycoprotein expressed on the surface of nearly all the nucleated cells. The main function of MHC type 1 presentation of peptide to antigen to Tc cells.
- Consists of two polypeptide chain:
- Alpha chain– Alpha molecule is of 45 kDa. Each molecule consists of 30 amino acids.
- Beta chain- It is of 12KDa.
- Beta-2 microglobulin: Similarly size in organisation to alpha-3.
- Bound non-covalently to alpha domain.
MHC type 2
- Glycoprotein are present value on specialised (APC) including macrophages dendritic cell to present T-cell or B- cell. For production of antibody as well as neutralizing cell mediated immunity.
- T- helper cells are finally activated upon binding with macrophages and dendritic cell, MHC to antigen.
- Consists of two different polypeptide chain
- Alpha chain- 33KDa
- Beta chain – 28KDa
MHC type 3
- It is group of protein which structure and function are two poorly known.
- They are not involved in antigen binding; only few of them are actively involved in immunity, while most of them engage in cell communication.
- They are mainly known from these genes because the cluster is present in between class 1 and class 2 MHC.
- The genes of type 3 molecules are signaling molecules of TNF and HSP.
- Insulin dependent diabetes mellitus.
- Multiple sclerosis
- Rheumatoid arthritis
Difference between MHC TYPE 1 and TYPE 2
|Type 1|| Type 2
Major Histocompatibility complex (MHC): Introduction, Types and Difference
- Animal and plant viruses, prions, and viroids
- Difference between Prokaryotes and Eukaryotes
- Antibody or Immunoglobulin
References and Sources