Broadly Neutralizing Antibody Responses in a Subset of HIV-1-Infected Individuals in Chennai, India

Abstract

Identification of broadly neutralizing antibodies (NAbs) generated during the course of HIV-1 infection is essential for effective HIV-1 vaccine design. The magnitude and breadth of neutralizing activity in the sera from 46 antiretroviral treatment–naive HIV-1 clade C-infected individuals was measured in a single round infection assay using TZM-bl cells and multisubtype panel of env-pseudotyped viruses. Higher levels of NAb response (NAb titer 500 to >40 000) were measured in these patients against tier 1 and tier 2 viruses. The average magnitude of the NAb responses of chronically infected individuals against heterologous viruses was consistently higher than the response observed from individuals with long-term nonprogressor ( P = .086). To conclude, high titers of HIV-1 cross-neutralizing activity were observed in the sera from a subset of HIV-1-infected individuals in Chennai, India. Additional studies of the epitopes recognized by these antibodies may facilitate the discovery of an effective vaccine immunogen.