APC-targeted immunization for the treatment of HIV-1

Therapeutic immunization may be thought of as an adjunct to highly active antiretroviral therapy to prime the immune system and possibly correct for immunological defects. Most therapeutic vaccine strategies currently under investigation aim to increase HIV-specific cellular responses. This may be most successfully accomplished by utilizing professional antigen-presenting cells. Autologous dendritic cells may be isolated, cultured, loaded with antigen and re-injected into the subject (ex vivo) or antigen may be directly delivered in situ to Langerhans cells or dermal dendritic cells, which are located respectively at the epidermal and dermal layer of the skin. Once Langerhans cells or dermal dendritic cells have incorporated the antigen, they are expected to mature and migrate to the lymph node to present antigen and stimulate naive T-cells. Exciting results have been obtained in nonhuman primates with both ex vivo and topical antigen-presenting cell-based therapeutic immunization.