Human Immunodeficiency Virus Type 1 V1-to-V5 Envelope Variants from the Chronic Phase of Infection Use CCR5 and Fuse More Efficiently than Those from Early after Infection

Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Cambridge, Massachusetts 02139, USA.
Journal of Virology (Impact Factor: 4.44). 08/2009; 83(19):9694-708. DOI: 10.1128/JVI.00925-09
Source: PubMed


Human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein modifications over the course of infection have been associated with coreceptor switching and antibody neutralization resistance, but the effect of the changes on replication and host cell receptor usage remains unclear. To examine this question, unique early- and chronic-stage infection envelope V1-to V5 (V1-V5) segments from eight HIV-1 subtype A-infected subjects were incorporated into an isogenic background to construct replication-competent recombinant viruses. In all subjects, viruses with chronic-infection V1-V5 segments showed greater replication capacity than those with early-infection V1-V5 domains in cell lines with high levels of both the CD4 and the CCR5 receptors. Viruses with chronic-infection V1-V5s demonstrated a significantly increased ability to replicate in cells with low CCR5 receptor levels and greater resistance to CCR5 receptor and fusion inhibitors compared to those with early-infection V1-V5 segments. These properties were associated with sequence changes in the envelope V1-V3 segments. Viruses with the envelope segments from the two infection time points showed no significant difference in their ability to infect cells with low CD4 receptor densities, in their sensitivity to soluble CD4, or in their replication capacity in monocyte-derived macrophages. Our results suggest that envelope changes, primarily in the V1-V3 domains, increase both the ability to use the CCR5 receptor and fusion kinetics. Thus, envelope modifications over time within a host potentially enhance replication capacity.

Download full-text


Available from: Anupa Kamat, Apr 03, 2014
  • Source
    • "VRC01, PGT121, and 10E8 antibodies were generated by the transfection of 293F cells with immunoglobulin heavy and light chain plasmids containing the appropriate variable loop domains as described previously (Huang et al., 2012; Sagar et al., 2012; Walker et al., 2011; Wu et al., 2010). Infection of TZM-bl cells in the absence and presence of twofold serial dilution of the antibody was used to estimate the 50% inhibitory concentration (IC 50 ) as previously described (Etemad et al., 2009). All reported IC 50 s are mean estimates from a minimum of two independent assays. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Recent studies suggest that single genome amplification (SGA) as compared to standard bulk PCR and virus stocks from 293 T transfection versus short term passage in peripheral blood mononuclear cells (PBMC) yield a less biased representation of HIV-1 envelope characteristics. In 9 different subjects, genetic diversity, divergence, and population structure was not significantly different among SGA or bulk PCR amplified envelope V1-V3 segments. In these subjects, 293 T transfection derived virus stocks with SGA or bulk PCR amplified envelopes had similar infectivity, replication kinetics, co-receptor usage, and neutralization susceptibility. While PBMC passage as compared to the 293 T derived virus stocks had similar co-receptor usage, PBMC viruses were less neutralization susceptible to some specific antibodies. Our results suggest that the method of envelope sequence amplification, either SGA or bulk PCR, does not have a significant impact on the genotypic and phenotypic properties of the virus envelope quasispecies.
    Full-text · Article · Feb 2015 · Journal of Virological Methods
  • Source
    • "Target cells at the site of invasion potentially have low cell surface CD4 and CCR5 concentrations, and viruses with an enhanced ability to infect these cells may have an advantage during transmission [39]. We and others have shown that sensitivity to receptor blockers correlates with a virus’ ability to replicate in cells with limiting receptor levels [24,40]. Viruses with a capacity to infect cells that have low receptor levels demonstrate high inhibitor IC50s, while variants that require high CD4 or CCR5 show low IC50s against the receptor blocker. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Previous studies suggest that active selection limits the number of HIV-1 variants acquired by a newly infected individual from the diverse variants circulating in the transmitting partner. We compared HIV-1 envelopes from 9 newly infected subjects and their linked transmitting partner to explore potential mechanisms for selection. Recipient virus envelopes had significant genotypic differences compared to those present in the transmitting partner. Recombinant viruses incorporating pools of recipient and transmitter envelopes showed no significant difference in their sensitivity to receptor and fusion inhibitors, suggesting they had relatively similar entry capacity in the presence of low CD4 and CCR5 levels. Aggregate results in primary cells from up to 4 different blood or skin donors showed that viruses with envelopes from the transmitting partner as compared to recipient envelopes replicated more efficiently in CD4+ T cells, monocyte derived dendritic cell (MDDC) - CD4+ T cell co-cultures, Langerhans cells (LCs) - CD4+ T cell co-cultures and CD4+ T cells expressing high levels of the gut homing receptor, alpha4beta7, and demonstrated greater binding to alpha4beta7 high / CD8+ T cells. These transmitter versus recipient envelope virus phenotypic differences, however, were not always consistent among the primary cells from all the different blood or skin donation volunteers. Although genotypically unique variants are present in newly infected individuals compared to the diverse swarm circulating in the chronically infected transmitting partner, replication in potential early target cells and receptor utilization either do not completely dictate this genetic selection, or these potential transmission phenotypes are lost very soon after HIV-1 acquisition.
    Full-text · Article · Dec 2013 · Retrovirology
  • Source
    • "The difference in PSC-RANTES susceptibility between the early w2 and end-stage w13 viruses in BT78 approaches significance (p=0.06), consistent with reports that the late R5 viruses in HIV-1 infected individuals without detectable X4 viruses use the CCR5 coreceptor better [6,37-41]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Background We previously reported that adoption of an “open” envelope glycoprotein (Env) to expose the CD4 binding site for efficient receptor binding and infection of cell targets such as macrophages that express low levels of the receptor represents an early event in the process of coreceptor switch in two rapidly progressing (RP) R5 SHIVSF162P3N-infected rhesus macaques, releasing or reducing Env structural constraints that have been suggested to limit the pathways available for a change in coreceptor preference. Here we extended these studies to two additional RP monkeys with coreceptor switch and three without to confirm and identify additional factors that facilitated the process of phenotypic conversion. Results We found that regardless of coreceptor switching, R5 viruses in SHIVSF162P3N-infected RP macaques evolved over time to infect macrophages more efficiently; this was accompanied by increased sCD4 sensitivity, with structural changes in the CD4 binding site, the V3 loop and/or the fusion domain of their Envs that are suggestive of better CD4 contact, CCR5 usage and/or virus fusion. However, sCD4-sensitive variants with improved CD4 binding were observed only in RPs with coreceptor switch. Furthermore, cumulative viral load was higher in RPs with than in those without phenotypic switch, with the latter maintaining a longer period of seroconversion. Conclusions Our data suggest that the increased virus replication in the RPs with R5-to-X4 conversion increased the rate of virus evolution and reduction in the availability of target cells with optimal CD4 expression heightened the competition for binding to the receptor. In the absence of immunological restrictions, variants that adopt an “open” Env to expose the CD4 binding site for better CD4 use are selected, allowing structural changes that confer CXCR4-use to be manifested. Viral load, change in target cell population during the course of infection and host immune response therefore are interdependent variables that influence R5 virus evolution and coreceptor switch in SHIVSF162P3N-infected rhesus macaques. Because an "open" Env conformation also renders the virus more susceptible to antibody neutralization, our findings help to explain the infrequent and late appearance of X4 virus in HIV-1 infection when the immune system deteriorates.
    Full-text · Article · Dec 2012 · Retrovirology
Show more