Background During acute HIV infection (AHI), CD4+ T cells undergo apoptosis from direct infection and through bystander apoptosis induced by inflammatory factors. Both the inflammatory factors and apoptotic material produced during AHI may negatively impact innate and adaptive immune responses. Such inhibitory factors present in AHI plasma include apoptotic microparticles (MPs), small membranous blebs derived from dying cells. Dendritic cells (DCs) are the sentinel cells of the immune system that respond to pathogens, frequently through Toll-like receptor (TLR) recognition of unique pathogenic macromolecules. Because TLR recognition of viral material by DCs is important for DC priming of virus-specific T cells, we determined how AHI patient plasma or apoptotic MPs affect TLR-stimulated DCs.