Impact of the Maraviroc-Resistant Mutation M434I in the C4 Region of HIV-1 gp120 on Sensitivity to Antibody-Mediated Neutralization

Higher Genetic Diversity and Viral Evolution in Key Regions of the Envelope Gene Are Associated with Broader Neutralizing Antibody Responses: a Report of Two Chronic HIV Infected Cases

Dozens of broadly neutralizing antibodies (bnAbs) have been identified from chronically infected HIV-1 patients, but it is still unclear what determines the acquisition of broad neutralizing activities. Two chronic HIV-1 infected cases with similar autologous neutralizing activities were followed up for two years to study the viral evolution of the envelope gene and the neutralizing activity against autologous and heterologous viruses. The neutralization activities against homologous viruses gradually increased in both patients. HA172 eventually developed a cross-clade neutralizing antibodies response, with a neutralization breadth of 88.9% (8/9) against tier 2 heterologous HIV-1. However, HA084 could only neutralize 44.4% (4/9) of the same virus panel. Higher genetic diversity of the env gene at baseline (0.027 vs. 0.002, p ＜ 0.001), stronger immune pressure on V3 (3.08 vs. 0.99, p ＜ 0.001) or V4 loops (2.63 vs. 0.62, p = 0.002), increasing length of V1V2 and V4 loops, and evolution on V1V2 and CD4-binding sites (CD4bs) were identified in HA172. The findings demonstrated that higher viral genetic diversity, viral evolution on V1V2 and CD4bs might contribute to the development of bnAbs. The findings indicate the possibility of inducing better neutralizing antibodies in immunodeficient patients and may help develop an immune therapy strategy based on bnAbs.

A novel dual-luciferase assay for anti-HIV drug screening based on the CCR5/CXCR4 promoters

Acquired immunodeficiency syndrome (AIDS) is a serious worldwide disease caused by infection with the human immunodeficiency virus (HIV). C-C chemokine receptor 5 (CCR5) and C-X-C chemokine receptor 4 (CXCR4) are important coreceptors mediating HIV-1 cell entry. Many new anti-HIV drugs are currently in preclinical and clinical trials; however, drug development has proceeded slowly partly because of the lack of a high-throughput system to screen these drugs. Here, we describe the development of a novel dual-luciferase assay using a CCR5/CXCR4 promoter-driven firefly and Renilla luciferase vector (pGL4.10-RLUC-CCR5/CXCR4). Drugs were screened for the ability to regulate CCR5 and CXCR4 promoter activities. The CCR5 and CXCR4 promoters were inserted separately into the recombinant vector and transfected into the acute T lymphocyte leukemia cell line H9. Treatment of stable transfected cells with four traditional Chinese medicine compounds resulted in the dose-dependent inhibition of the CXCR4 and CCR5 promoter activities. The dual-luciferase reporter assay provides a rapid and direct method to screen anti-AIDS/HIV drugs.