DENDRITIC CELL-T CELL MIXTURES, ISOLATED FROM THE SKIN AND MUCOSAE OFMACAQUES, SUPPORT THE REPLICATION OF SIV

Previous studies have shown that HIV-1 exploits dendritic cells (DCs) to replicate and spread among CD4(+) T cells, The DCs within mucosal s urfaces may be especially important, but these are more difficult to a ccess, To study more extensively the properties of DCs and other leuko cytes from skin and different mucosae, DCs were isolated from uninfect ed macaques and their sensitivity assessed to infection with SIV in vi tro, Dendritic cells and T cells readily emigrated from organ cultures of macaque skin, as described previously for humans, In addition, cha racteristic cells emigrated from explants of mucosae, both nasopharyng eal (adenoid and tonsil) and genital (vagina and cervix), The macaque DCs reacted with the monoclonals that are used to study human DCs, suc h as MAbs to CD40, CD86, CD83, and the p55 protein, When SIV was added to the DC-T cell mixtures from these different organs, extensive repl ication was observed in all but the cervical leukocytes, SIV replicati on occurred without the use mitogens, and with virus that had been gro wn in a cell line in the absence of mitogens and IL-2, Most of the new ly synthesized viral protein is observed in syncytia, Therefore, mixtu res of DCs and T cells isolated from mucosal surfaces served as a natu rally permissive environment for SIV replication.