Characterization of the single cycle replication of HIV-1 expressing Gaussia luciferase in human PBMCs, macrophages, and in CD4(+) T cell-grafted nude mouse.

In this study, we have described a sensitive HIV-1 single cycle replicating virus that expresses a secreted Gaussia luciferase (Gluc) as a biomarker. This single cycle replicating virus was produced by the co-transfection of 293T cells with a multiple gene-deleted HIV provirus (ΔRI/ΔE/Gluc) and CMVin-Gag/Pol and viral envelope glycoprotein (Env) plasmids. The results showed that this HIV-1 virus efficiently infected and was restricted to one replication cycle in primary CD4+ T cells, macrophages and CD4+ T cell-grafted nude mouse. Because the viral genomic DNA lacks reverse transcriptase and integrase genes and has a partial deletion in the env gene, this trans-complemented virus could not be converted into the wild type virus after multiple passages in highly susceptible CD4+ C8166 T cells, demonstrating the safety of this system. Furthermore, infection with this virus was easily monitored by detecting the Gluc activity in the cell culture supernatants or in the animal peritoneal fluid or blood, which was shown to be more sensitive than the anti-p24 ELISA assay. This trans-complemented virus system is valuable for various HIV single cycle infection and viral expression studies in the laboratory where a biosafety level-3 containment facility is not accessible.