New Knowledge About CCR5, HIV Infection, and Disease Progression: Is "Old" Still Valuable?

C-C chemokine receptor (CCR) 5 (CCR5) is the main HIV-1 coreceptor involved in virus entry and cell-to-cell spread during acute and chronic infections: such CCR5 and T cell tropic viruses are adapted to and replicate in CD4 memory T cells. Polymorphisms in regulate CCR5 expression, which, in turn, influences HIV infection acquisition and subsequent disease progression. Among these polymorphisms, a 32-bp deletion in the open reading frame ( Δ32) and a single nucleotide polymorphism (SNP) in the promoter (-2459G/A) are the most well-characterized polymorphisms. Δ32 provides partial to full protection against HIV infection and, therefore, serves as a basis for gene deletion studies attempting to achieve a permanent HIV cure. Recent studies have discovered that certain SNPs in the region, not within , also affect CCR5 expression, HIV infection, and disease progression. Although these studies provide further valuable information regarding the role of human genetic variation in HIV/AIDS, they did not incorporate -2459G/A. In this article, the author summarizes the knowledge gained through the discovery of these new SNPs and introduces the idea that by not incorporating -2459G/A, less comprehensive conclusions may have been reached. Until a strategy that delivers a cure to the millions is found, every piece of information that may help curtail the HIV/AIDS threat to public health should be considered useful.