CCL3L1 dose and HIV-1 susceptibility.

Several genetic factors influence HIV-1 susceptibility or AIDS disease progression. A recent study reported on what could be a particularly important genetic determinant for HIV-1 susceptibility and disease progression: copy number of a chemokine gene termed CCL3L1. Individuals with low copy numbers of the gene, relative to their ethnic background, were associated with markedly enhanced HIV-1/AIDS susceptibility. These findings define an important new genetic determinant of HIV-1 susceptibility and further emphasize the importance of the chemokine system, either as elements that inhibit HIV-1 infection or that modulate antiviral immune responses.