Purpose of review: To present evidence of the role of innate mucosal immunity and to harness this arm of immunity in protection against HIV infection.
Recent findings: Dendritic cells, monocytes, natural killer (NK) cells and γδ T cells are critical in innate immunity, which is mediated by Toll-like receptor (TLR) and recently identified stress pathways. Complement factors, cytokines and chemokines have diverse functions usually affecting HIV infection indirectly. A novel group of innate intracellular HIV restriction factors has been identified - APOBEC3G, TRIM5α and tetherin - all of which are upregulated by type I interferons and some by vaccination and TLR agonists. Whereas innate immunity conventionally lacks memory, recent evidence suggests that some of the cells and intracellular factors may express immunological memory-like features.
Summary: Innate mucosal immunity may provide early effective control of HIV transmission and replication. Some vaccines can enhance innate immune factors, such as APOBEC3G and control HIV during the eclipse period, allowing full weight of neutralizing and/or cytotoxic T cells to develop and prevent mucosal HIV infection. The next generation of vaccines should be designed to target both innate and adaptive immune memory responses.