Urology>>>>>Basic Science and Molecular Oncology
Question 9#

Regarding the major histocompatability complex (MHC), which of following is FALSE?

A. MHC Class I molecules are associated with a light chain, beta-2 microglobulin
B. T lymphocytes are unable to recognise antigens bound to the MHC molecules
C. MHC is involved in recognising and binding to foreign antigens
D. MHC Class II molecules are composed of two heavy chains each with two domains
E. MHC Class III proteins include cytokines

Correct Answer is B

Comment:

Answer B

MHC are genes that are found on DNA that code for proteins such as the MHC molecules. T lymphocytes recognise antigens, including tumour antigens, which are bound to MHC molecules on antigen presenting cells.

There are three classes of MHC molecules, I, II and III.

MHC Class I molecules are made up of transmembrane heavy chains (alpha 1, 2 and 3 domains) associated with a light chain, beta-2 microglobulin.

MHC Class II molecules are made of two transmembrane heavy chains each containing two domains, alpha 1/alpha 2 and beta 1/beta 2.

MHC Class III proteins include components of the complement system such as cytokines.