Microbial dysbiosis in HIV is characterized by decreased abundances of Bacteroides, Lactobacillus and beneficial clostridia with increased abundances of Prevotella and pathogenic Proteobacteria, increasing T-cell and DC activation. Loss of secretory IgA may help to explain the outgrowth of pathogenic bacteria. Increased neutrophil and macrophage accumulation in the lamina propria, bacterial activity in the mucosa, and other mechanisms destabilize the mucosa and GI epithelium, leading to MT and further accumulation of inflammatory microbial products and cytokines in circulation. Together, these mechanisms perpetuate an inflammatory cycle that leads to chronic immune activation in ART-treated HIV-infected individuals. ART, antiretroviral therapy; DC, dendritic cell; GI, gastrointestinal; LPS, lipopolysaccharide; MT, microbial translocation. Source: Lyle-Mckinnon et al., 2015.

International Union of Immunological SocietiesUniversity of South AfricaInstitute of Infectious Disease and Molecular MedicineElizabeth Glazer Pediatric Aids FoundationStellenbosch University