The receptor through which M-tropic HIV strains bind? (AIIMS May 2011)
|D||Any of the above|
a. “The entry of HIV into cells requires the CD4 molecule, which acts as a high-affinity receptor for the virus. This explains the tropism of the virus for CD4+ T cells and its ability to infect other CD4+ cells, particularly macrophages and DCs.
b. However, binding to CD4 is not sufficient for infection; the HIV envelope gp120 must also bind to other cell surface molecules (co-receptors) to facilitate cell entry.
c. Two cell surface chemokine receptors, CCR5 and CXCR4, serve this role. HIV envelope gp120 (non-covalently attached to transmembrane gp41) binds initially to CD4 molecules. This binding leads to a conformational change that exposes a new recognition site on gp120 for the CXCR4 (mostly on T cells a/k/a T trophic strains) or CCR5 (mostly on macrophages a/k/a M trophic strains) coreceptors. ”