A protocol for anti-CD4 IgG antibody purification using plasma samples from people with HIV and antibody-mediated cytotoxicity

Abstract

Background. Up to 20% of people with HIV (PWH) fail to recover their CD4+ T cell counts to levels similar to healthy controls after suppressive antiretroviral therapy (ART). Immune non-responders (INRs) are PWH on suppressive ART with CD4+ T cell counts lower than 350 cells/mL, whereas their CD8+ T cell counts are higher than healthy controls. We are the first group to report that increased anti-CD4 autoantibody IgGs in INRs are responsible for blunted CD4+ T cell reconstitution in PWH with ART and viral suppression through anti-CD4 IgG-induced antibody-mediated cytotoxicity (ADCC) against CD4+ T cells in vitro. Notably, anti-CD4 IgG-mediated poor CD4+ T cell recovery from suppressive ART is the only mechanism targeting CD4+ T cells, specifically. Results. We provide a detailed one-by-one step protocol from antigen-specific antibody isolation using plasma samples, to ADCC assay. Conclusions. To promote reproducible research, a detailed protocol for isolating anti-CD4 IgG autoantibodies from plasma samples of PWH and evaluating ADCC effects is reported here. • Antigen-specific antibody isolation using human plasma samples • Antibody-mediated cytotoxicity (ADCC)

Keywords

• Antibody purification and mediated cytotoxicity