Immunometabolic defects of CD8+ T cells disrupt gut barrier integrity in people with HIV

A hallmark of HIV infection is disruption of intestinal barrier integrity that persists in people with HIV (PWH) despite treatment with antiretroviral therapy (ART). This disruption is central to HIV disease progression, yet the causes remain incompletely understood. We report a mechanism by which immunometabolic defects in colon-resident CD8⁺ T cells in PWH lead to intestinal epithelial apoptosis and disruption of intestinal barrier integrity. We show that in PWH, these cells downregulate the lipid sensor peroxisome proliferator-activated receptor-γ (PPARγ), which results in reduced intracellular lipid droplets, impaired fatty acid oxidation, and acquisition of lipids by CD8⁺ T cells from intestinal epithelial cells, which then contributes to epithelial cell death. Our findings indicate that HIV-associated immunometabolic dysregulation of colon CD8⁺ T cells leads to loss of intestinal epithelial homeostasis. These results identify potential strategies to reduce comorbidities in PWH and other disorders with disrupted intestinal barrier integrity.