The Molecules of HIV

Note: this site last updated in 2006


An article from "The Molecules of HIV" (c) Dan Stowell

CCR5 is the chemokine receptor which HIV uses as a coreceptor to gain entry into macrophages. Certain strains of HIV target macrophages rather than T cells, because their envelope protein is configured such that it works best with CCR5 as a coreceptor - these strains are called macrophage-tropic. (Interestingly, macrophage-tropic strains tend not to be able to induce syncytia.)

CCR5 is perhaps the most important of the known coreceptors for HIV, since the most commonly transmitted strains of HIV are strains that bind to CCR5 - so-called "R5" strains.

The level of CCR5 expression is upregulated in chronic HIV infection - that is, HIV infection causes more CCR5 to be produced than would otherwise occur. Measuring the expression of CCR5 is therefore one indicator of an individual's disease progression. Studies have found that CCR5 expression decreases after a person receives HAART treatment - but not as far as returning it to "normal" levels.

Compare CCR5 with CXCR4%20and%20R5">CXCR5">CXCR4 and R5">CXCR5, which HIV uses as coreceptors for gaining entry to lymphocytes">lymphocytes">T lymphocytes">lymphocytes.

The CCR5-Delta32 mutation and HIV resistance

There has been some recent media coverage about a group of individuals with high resistance to HIV infection. These people have a mutation in their CCR5 gene which seems to confer resistance - for more information read my delta32 page.

Written by
Dan Stowell

Creative Commons License