Dependence on the CCR5 coreceptor for viral replication explains the lack of rebound of CXCR4-predicted HIV variants in the Berlin patient

Abstract

The "Berlin patient" is the first patient cured of HIV-1 infection after allogeneic transplantation with nonfunctional CCR5 coreceptor stem cells. We demonstrate that CXCR4-predicted minority viruses present prior to transplantation were unable to rebound after transplantation due to their dependence on CCR5 for replication and high genetic barrier toward CXCR4 usage.

Keywords: Berlin-Patient; HIV; coreceptor; cure; stem cell transplantation.

Figure 1.

Coreceptor tropism prediction of patient derived gp120-V3 loop sequences obtained prior to stem cell transplantation. Schematic representation of gp120-V3 loop amino acid sequences of the patient-derived dominant CCR5-predicted variant (Rbp) and CXCR4-predicted minority variants, X1bp–X7bp, and the control viruses cBaL and cHXB2. Genotypic tropism prediction by Geno2Pheno[_coreceptor] (10% false-positive rate) [7], PSSM_X4-R5, net charge rule, and 11/25 is given. CCR5 prediction is indicated in green; CXCR4 prediction in red.

Figure 2.

Replication capacity and phenotypic coreceptor usage. A, Replication capacity analysis in peripheral blood mononuclear cells (PBMCs) from healthy donors expressing both coreceptors CCR5 and CXCR4 (picogram [pg] p24/100 µL supernatant at day 7). B, Coreceptor usage was determined by expressing the percentage of viral entry in CXCR4 or CCR5 U373-MAGI cells. C, Replication capacity in PBMCs from healthy donors with 1 µM MVC (CCR5 antagonist) or 10 µM AMD-3100 (CXCR4 antagonist) or without inhibitor (pg p24/100 µL supernatant at day 7). D, Replication capacity in patient-derived PBMCs obtained after allogeneic homozygous CCR5-Δ32 stem cell transplantation (SCT) as tested with 10 µM AMD-3100 or without inhibitor (pg p24/100 µL supernatant at day 7). cHXB2 and cBal were used as control viruses. Rbp is the dominant CCR5-predicted viral construct and X1bp–X5bp are the viable Geno2Pheno_[coreceptor) CXCR4-predicted viral constructs. Error bars are standard deviation of quadruplicate wells. All experiments were performed at least twice, and the figures are based on 1 representative experiment.