Simultaneous zinc-finger nuclease editing of the HIV coreceptors ccr5 and cxcr4 protects CD4+ T cells from HIV-1 infection.

HIV-1 entry into CD4(+) T cells requires binding of the virus to CD4 followed by engagement of either the C-C chemokine receptor 5 (CCR5) or C-X-C chemokine receptor 4 (CXCR4) coreceptor. Pharmacologic blockade or genetic inactivation of either coreceptor protects cells from infection by viruses that exclusively use the targeted coreceptor. We have used zinc-finger nucleases to drive the simultaneous genetic modification of both ccr5 and cxcr4 in primary human CD4(+) T cells.

Quantitative phosphoproteomics reveals extensive cellular reprogramming during HIV-1 entry.

Receptor engagement by HIV-1 during host cell entry activates signaling pathways that can reprogram the cell for optimal viral replication. To obtain a global view of the signaling events induced during HIV-1 entry, we conducted a quantitative phosphoproteomics screen of primary human CD4(+) T cells after infection with an HIV-1 strain that engages the receptors CD4 and CXCR4. We quantified 1,757 phosphorylation sites with high stringency.

Transmitted/founder and chronic HIV-1 envelope proteins are distinguished by differential utilization of CCR5.

Infection by HIV-1 most often results from the successful transmission and propagation of a single virus variant, termed the transmitted/founder (T/F) virus. Here, we compared the attachment and entry properties of envelope (Env) glycoproteins from T/F and chronic control (CC) viruses. Using a panel of 40 T/F and 47 CC Envs, all derived by single genome amplification, we found that 52% of clade C and B CC Envs exhibited partial resistance to the CCR5 antagonist maraviroc (MVC) on cells expressing high levels of CCR5, while only 15% of T/F Envs exhibited this same property.

Kruppel-like factor 2 modulates CCR5 expression and susceptibility to HIV-1 infection.

CCR5, a cell surface molecule critical for the transmission and spread of HIV-1, is dynamically regulated during T cell activation and differentiation. The molecular mechanism linking T cell activation to modulation of CCR5 expression remains undefined. Kruppel-like factor 2 (KLF2) is a transcription factor that promotes quiescence, survival, and in part by modulating chemokine receptor levels, induces homing to secondary lymphoid organs.