Antibody Responses to HIV-1 gp120 Hypervariable Regions in Six Long-Term Non-Progressors

Our long-term goal is to discover the combination of host parameters that help some HIV-infected individuals to resist progression to AIDS. In this study, we examined antibody responses using multiple samples obtained from a cohort of Long-Term Non-Progressors (LTNPs). Our hypothesis is that antibody responses to variable regions of the HIV-1 envelope glycoprotein are involved in reducing the viral load associated with LTNPs and that these specific immune responses influence susceptibility to disease progression. Multiple plasma samples were obtained from patients identified as LTNPs with the objective of characterizing humoral immune response directed to the five hypervariable regions of the envelope glycoprotein. Antibody binding was tested against peptides representing the five hypervariable regions of gp120, as well as against analog peptides representing different isolates of HIV-1 and against recombinant envelope glycoprotein. LTNPs have specific antibodies to the hypervariable regions of the envelope glycoprotein and develop different patterns of antibody recognition to variable epitopes of envelope glycoprotein. These antibodies can be detected using HIV peptides as capture antigens.