Dendritic cells in progression and pathology of HIV infection

• HIV poorly infects DCs, but DCs efficiently transinfect CD4+ T cells.
• DCs may help the initial HIV infection and spreading through chemokine secretion.
• Activation of pDCs by HIV involves IFNα secretion, but cDCs are poorly activated.
• DC frequencies and innate functions are altered during acute and chronic infection.
• Chronic DC stimulation contributes to T cell exhaustion.

Although the major targets of HIV infection are CD4+ T cells, dendritic cells (DCs) represent a crucial subset in HIV infection because they influence viral transmission and target cell infection and presentation of HIV antigens. DCs are potent antigen-presenting cells that can modulate antiviral immune responses. Through secretion of inflammatory cytokines and interferons (IFNs), DCs also alter T cell proliferation and differentiation, participating in the immune dysregulation characteristic of chronic HIV infection. Their wide distribution in close proximity with the mucosal epithelia makes them one of the first cell types to encounter HIV during sexual transmission. We discuss here the multiple roles that DCs play at different stages of HIV infection, emphasizing their relevance to HIV pathology and progression.