Arsenic modulates APOBEC3G-mediated restriction to HIV-1 infection in myeloid dendritic cells

DC are major targets of HIV-1 during the early events of infection. Yet, HIV-1 infects these cells only inefficiently in vitro as compared with CD4T lymphocytes. Accordingly, we have previously identified a strong post-entry block to HIV-1 replication in MDDC as a result of the cellular restriction factor A3G. Furthermore, we have demonstrated that As2O3, a drug used to treat acute promyelocytic leukemia, can fully eliminate the potent post-entry restriction of HIV-1 infection in MDDC and in blood-derived MyDC by mechanisms that were unclear. We are now exploring the interplay between As2O3 and A3G-mediated restriction in primary DC subsets. Here, we report that As2O3 counteracts A3G-mediated restriction in MyDC but not in MDDC. RNAi of A3G in MyDC indicated that the As2O3-mediated increase of HIV-1 infection was largely dependent on the presence of the cellular restriction factor. This study reveals an unexpected interplay between As2O3 and A3G-mediated restriction to HIV-1 infection in primary human MyDC. J. Leukoc. Biol. 88: 1251–1258; 2010.