Infection of oral mucosal cells by human immunodeficiency virus type 1 in seropositive persons

Molecular studies have revealed significant amounts of human immunodeficiency virus type 1 (HIV-1) provirus DNA in saliva of HIV-infected persons. However, cellular localization has not been determined. In situ polymerase chain reaction (IS-PCR) was done on saliva-associated cells for localization of HIV-1 provirus DNA. Results indicate its presence in the nuclei of saliva-associated epithelial cells in 29 (83%) of 35 HIV-1-seropositive subjects. In 24 (83%) of the 29 IS-PCR-positive samples, 0.1%-4.0% of the mucosal epithelial cells exhibited nuclear localization of HIV-1 DNA. In addition, HIV-1 provirus DNA was detected in monocytes or lymphocytes of all salivary samples from the 35 subjects. The localization of HIV-1 provirus DNA indicates that epithelial cells are another cell type infected by HIV-1 in vivo. These findings suggest epithelial cells in other body sites might also be infected with HIV-1.