The microbiota and HIV: shedding light on dark matters
The gut, which is the major reservoir of T lymphocytes, suffers severe T-cell depletion when attacked by HIV. These T cells are essential for recognizing and processing antigen and for maintaining the integrity of the gut mucosa, the extraordinarily selective barrier between the systemic circulation and the gut's microbes and other contents. Landmark studies by Brenchley et al.[1,2] revealed that HIV-mediated depletion of the gut's CD4+ T cells results in low-grade, steady leakage of gut microbes and metabolites into the circulation, which drives immune activation and HIV replication and pathogenesis.