Abstract
BackgroundHIV-1 produces defective mutants in the process of reproduction. The significance of the mutants has not been well investigated.MethodsThe plasmids of wild type (HIV-1NL4–3) and Env-defective (HIV-1SG3ΔEnv) HIV-1 were co-transfected into HEK293T cells. The progeny virus was collected to infect MT4 cells. The env gene and near-full-length genome (NFLG) of HIV-1 were amplified and sequenced. The phylogenetic diversity, recombinant patterns and hotspots, and the functionality of HIV-1 Env were determined.ResultsA total of 42 env genes and 8 NFLGs were successfully amplified and sequenced. Five types of recombinant patterns of env were identified and the same recombinant sites were detected in different patterns. The recombination hotspots were found distributing mainly in conservative regions of env. The recombination between genes of HIV-1NL4–3 and HIV-1SG3Δenv increased the variety of viral quasispecies and resulted in progeny viruses with relative lower infectious ability than that of HIVNL4–3. The defective env genes as well as NFLG could be detected after 20 passages.ConclusionThe existence of the defective HIV-1 promotes the phylogenetic evolution of the virus, thus increasing the diversity of virus population. The role of defective genes may be converted from junk genes to useful materials and cannot be neglected in the study of HIV-1 reservoir.
Highlights
Human immunodeficiency virus type 1 (HIV-1) produces defective mutants in the process of reproduction
Diversity and phylogenetic analysis of HIV-1 provirus The plasmids pSG3Δenv and pNL4–3 were cotransfected into HEK 293 T cells and the progeny virus was used to infect MT4 cells
Since the recombination could have occurred during co-transfection or during viral replication in MT4 cells, we conducted single genome amplification with the genome DNA from the cotransfected HEK 293 T cells
Summary
HIV-1 produces defective mutants in the process of reproduction. The significance of the mutants has not been well investigated. Recombination can bypass Muller’s ratchet by recreating mutation free individuals from a population of mutants [7]. Recombination can both create and maintain genetic diversity in a population [8]. Recombination is a key mechanism that facilitates the persistence of virus with latent envelope genomic fragments in the productively infected cell population [10]. It is clear that antiviral drugs unlikely have effect on integrated viral DNA, and the efficiency of CRIS PR/Cas gene editing technology for integrated HIV-1 DNA may reduce because of the mutations on the defective virus [13]. The defective HIV-1 occupies a considerable proportion in infections, the significance of env-defective HIV-1 mutants has not been well investigated. The evolution of superinfection of env-defective and infectious wild type HIV-1 strains in long-term in vitro passages was investigated
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
