Early Initiation of Antiretroviral Therapy Preserves the Metabolic Function of CD4+ T Cells in Subtype C Human Immunodeficiency Virus 1 Infection

Abstract

Background Immune dysfunction often persists in people living with HIV (PLWH) on antiretroviral therapy (ART), clinically manifesting as HIV-1-associated comorbidities. Early ART initiation may reduce incidence of HIV-1-associated immune dysfunction and comorbidities. Immunometabolism is a critical determinant of functional immunity. We investigated the effect of HIV-1 infection and timing of ART initiation on CD4+ T-cell metabolism and function. Methods Longitudinal blood samples from PLWH that initiated ART either in hyperacute HIV-1 infection (HHI, before peak viremia) or chronic HIV-1 infection (CHI) were assessed for metabolic and immune functions of CD4+ T-cells. Metabolite uptake and mitochondrial mass (MM) were measured using fluorescent analogues and MitoTracker Green accumulation respectively, and were correlated to CD4+ T-cell effector functions. Results Initiation of ART during HHI prevented dysregulation of glucose uptake by CD4+ T-cells; but glucose uptake was reduced pre- and post-ART initiation in CHI. Glucose uptake positively correlated with IL-2 and TNF-⍺ production by CD4+ T-cells. CHI associated with elevated MM in CD4+ TEM that persisted post-ART and correlated with PD-1 expression. Conclusion ART initiation in HHI largely prevented metabolic impairment of CD4+ T-cells. ART initiation in CHI associated with persistently dysregulated immunometabolism of CD4+ T-cells that associated with impaired cellular functions and exhaustion.