A common genetic mutation significantly delays the progression of HIV disease, scientists at the National Institute of Allergy and Infectious Diseases (NIAID) have found.
Philip M. Murphy, M.D., and David H. McDermott, M.D., of NIAIDs Laboratory of Host Defenses, led a research team that screened blood samples from HIV-infected individuals for mutations in the gene for CCR5, a key HIV co-receptor. The CCR5 gene encodes a protein on human immune cells that helps HIV enter and infect those cells. Recent studies have shown that individuals who produce mutant forms of CCR5 protein are more likely to resist HIV infection or have slower HIV disease progression than individuals who produce normal CCR5 protein.
This time, the researchers wanted to see if mutations in the promoter, a region of the CCR5 gene that regulates the quantity, rather than quality, of CCR5 protein, might also influence HIV disease progression. Their suspicions that such mutations would slow disease progression were confirmed. The scientists discovered that individuals with promoter mutations in both of the CCR5 genes they inherited developed AIDS almost four years later, on average, than HIV-infected individuals who lacked the mutation. Laboratory analyses showed that the mutant promoter was 45 percent less active, and thus less effective at promoting CCR5 protein production, than the normal promoter.
Contact: John Bowersox
NIH/National Institute of Allergy and Infectious Diseases