Integrase-independent HIV-1 infection
HIV-1 possesses a viral protein, integrase (IN), which is necessary for its efficient integration in target cells. However, it has been reported that an IN-defective HIV strain is still capable of integration. Here, we assessed the ability of wild type (WT) HIV-1 to establish infection in the presence of IN inhibitors. Researchers observed a low, yet clear infection of inhibitor-incubated cells infected with WT HIV which was identical to cells infected with IN-deficient HIV. The IN-independent integration could be enhanced by the pretreatment of cells with DNA-damaging agents suggesting that integration is mediated by a DNA repair system. Significantly faster viral replication kinetics with augmented viral DNA integration was observed after infection in irradiated cells treated with IN inhibitor compared to non-irradiated cells. These results suggest that HIV DNA has integration potential in the presence of an IN inhibitor and may serve as a virus reservoir.