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Maraviroc Fully Inhibits Dual-R5 Virus in Dual/Mixed HIV-1 Infected Patient
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Reported by Jules Levin
CROI 2010 Feb 16-19 SF
Jori Symons1*, Steven van Lelyveld2, Andy IM Hoepelman2, Petra van Ham1, Dorien de Jong1, Annemarie MJ Wensing1 and Monique Nijhuis1
1 Department of Virology, 2 Department of Internal Medicine & Infectious Diseases, University Medical Center Utrecht, The Netherlands.
Author Conclusions
In this D/M infected patient MVC inhibits R5-tropic viruses and dual-R5-tropic viruses. During continuous treatment dual-X4 viruses were selected. This indicates MVC could play a role in treatment of D/M classified patients especially in the background of a (partly) active backbone. Translation of these data into clinical practice warrants diagnostic tools which can discriminate dual R5 viruses from their dual X4 counterparts.
Background
Currently, maraviroc (MVC) is only used in patients that harbour exclusively R5 tropic viruses. It was recently shown in vitro that some of the dual-tropic viruses are much more efficient in using the CCR5 coreceptor (dual-R5), whereas others use the CXCR4 coreceptor more efficiently (dual-X4). Furthermore, MVC can suppress in vitro the replication of dual-R5 tropic viruses. We hypothesize that also in D/M HIV-1 infected patients, MVC may suppress both the CCR5 and
dual-R5 tropic viruses.
Methods:
In one patient before start of MVC and during treatment, D/M coreceptor tropism was established by Original Trofile Assay, MT2 assay and genotypic V3 analysis. An in dept analysis of the MT2 virus culture was performed to obtain clonal isolates at each time point. U-373-MAGI cells, expressing CD4+CCR5+, CD4+CXCR4+, and CD4+ as a control, were infected to determine coreceptor preference. Donor PBMCs were used to determine MVC susceptibility
and viral replication. In all experiments Ball and HXB2 were used as R5-tropic and X4-tropic control viruses, resp.
Figure 1. CCR5- and CXCR4 dependent p24 production. Assay was
performed using U373-MAGI-CCR5E (green) and U373-MAGI-CXCR4CEM
(red) cells. Biological clones pre 1, pre 2 (baseline), post 1, post 2, post 3
(MVC therapy) HXB2 and Ball reference strains were used (MOI=0.01, 10
days).
Table 1. Genotypic analysis of V3 loop before start of MVC and two weeks after. Prediction of coreceptor usage by Geno2Pheno coreceptor. FPR 10%, green R5 prediction red X4 prediction.
Results
The clonal isolates represented the patient's plasma viral population as demonstrated by genotypic analysis (table 1), and were able to infect both CCR5 and CXCR4 bearing U373-MAGI cells (figure 1). Baseline clones demonstrated
clear CCR5 coreceptor preference (dual-R5) and were fully susceptible to MVC (figure 2). During MVC therapy the dual-R5 tropic viruses were replaced by viruses that use the CXCR4 coreceptor more efficiently (dual-X4). which could
not be fully inhibited by MVC (figure 2). The replication capacity of all viruses was comparable in PBMCs (figure 3).
Figure 2. MVC susceptibility assay in donor derived PBMCs. Biological
clones pre 1, pre 2 (baseline), post 1, post 2, post 3 (MVC therapy) HXB2
and Ball reference strains were used (MOI=0.001, 7 days).
Figure 3. Replication curve in donor derived PBMCs. Biological clones pre
1, pre 2 (baseline), post 1, post 2, post 3 (MVC therapy) HXB2 and Ball
reference strains were used (50 ng p24)
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