Inhibition of HIV-1 infection by siRNAs directed against CCR5

Vincent C. Auyeung
California Institute of Technology

RNA interference (RNAi), a form of dsRNA-mediated post-transcriptional gene silencing, is a versatile molecular technique that boasts exquisite target specificity. Our laboratory has applied this technology to inhibit HIV-1 infection in primary T cells through the specific knockdown of CCR5, a chemokine coreceptor required for HIV-1 infection (Qin et al., 2003). However, both the CCR5 knockdown and the reduction in HIV-1 infectivity were relatively modest. Here we present efforts to identify more potent siRNA target sequences against CCR5 using a PCR-based system to rapidly generate siRNA expression constructs. These constructs are cotransfected into 293T cells with a GFP-luciferase-CCR5 fusion construct to screen for high-potency sequences. In addition, we have explored the possibility of interferon-related side effects triggered by the introduction of dsRNA in both primary T cells and a lacZ-expressing mouse model. Our results provide reassurance that RNAi is a valid tool for target-specific, antiviral gene silencing.