The crucial gene encodes a protein called CC-CKR-5, which sits on the surface of immune cells and is used by HIV to infect the cells.
O'Brien of the National Cancer Institute in Frederick, Md., and his colleagues have found that those with the deletion in only one CC-CKR-5 gene enjoy no protection from HIV infection.
O'Brien notes that about 20 percent of white people appear to harbor the deletion in at least one CC-CKR-5 gene.
This immune cell surface protein, CC-CKR-5
, is commandeered by the most common strains of HIV (SN: 6/22/96, p.390).
The defects occur in a gene for an immune cell protein known as CC-CKR-5. The most common strains of HIV commandeer that protein in order to infect cells (SN: 6/22/96, p.
The discovery also strengthens the hypothesis that drugs which interfere with the interaction between HIV and CC-CKR-5 can safely slow the spread of the virus in infected individuals.
Now, in a discovery that offers an explanation for why some people exposed to the virus remain uninfected, several research groups report that the HIV most commonly found in people actually infects via CC-CKR-5, a different protein on the surface of immune cells.
The HIV that requires CC-CKR-5 "is the kind of virus transmitted during sex.