IN-VIVO AND IN-VITRO HIV-1 INFECTION OF E PITHELIAL DENDRITIC CELLS

The skin and mucosa are the first line of defense of the organism agai nst external agents, not only as a barrier between the body and the en vironment but also as the site of initiation of immune reactions. The immunocompetent epidermal cells which act as antigen-presenting cells (APC) are Langerhans cells (LC). Many indirect and/or direct experimen tal data have shown that LC may be a privileged target, reservoir and vector of dissemination for the human immunodeficiency virus (HIV) fro m the inoculation sites (mucosa?) to lymph nodes where the emigrated i nfected LC could infect T lymphocytes. In vitro infection confirms the ir permissivity to viral replication, HIV infection may modify the APC function of LC which could contribute to amplify the immunosuppressiv e state found in AIDS. Furthermore, mechanisms leading to the re-activ ation of viral expression at the cutaneous level need to be explored. An ideal animal model may readily clarify the role of LC in AIDS patho logy and in transmucosal infection.