Oral mucosal Langerhans' cells as target, effector and rector in HIV infection

The mechanism underlying a transition of the oral cavity mucosal epithelium towards susceptibility to opportunistic infections in HIV-seropositive pat ients was investigated, Phenotypic markers CD1a, HLA-DR, and CD86 of oral m ucosal Langerhans' cells (LCs), p17 core protein of human immunodeficiency virus (HIV), and CD45RO of memory T cells were labeled on oral hairy leukop lakia lesional biopsies and clinically normal autologous tissue of HIV-infe cted patients. HIV p17 protein was detected in association with mucosal LCs , mainly within the lesional epithelium. There were significant correlation s between the detection of HIV p17 and the depletion of LCs, and between th e depletion of LCs and the presence of hairy leukoplakia lesions. Conjugate s of activated LCs and memory T cells were also evident in the submucosal a rea of lesional biopsies. The findings from this study support the hypothes is that oral mucosal LCs are also the target of HIV infection. Cytopathic c hanges of LCs caused by productive HIV infection may contribute to selectiv e depletion of LCs, which may impair the mucosal immunologic protection aga inst colonization by microorganisms causing HIV-associated oral mucosal les ions.