title: Release of HIV-1 sequestered in the vesicles of oral and genital mucosal epithelial cells by epithelial-lymphocyte interaction.
abstract: Oropharyngeal mucosal epithelia of fetuses/neonates/infants and the genital epithelia of adults play a critical role in HIV-1 mother-to-child transmission and sexual transmission of virus, respectively. To study the mechanisms of HIV-1 transmission through mucosal epithelium, we established polarized tonsil, cervical and foreskin epithelial cells. Analysis of HIV-1 transmission through epithelial cells showed that approximately 0.05% of initially inoculated virions transmigrated via epithelium. More than 90% of internalized virions were sequestered in the endosomes of epithelial cells, including multivesicular bodies (MVBs) and vacuoles. Intraepithelial HIV-1 remained infectious for 9 days without viral release. Release of sequestered intraepithelial HIV-1 was induced by the calcium ionophore ionomycin and by cytochalasin D, which increase intracellular calcium and disrupt the cortical actin of epithelial cells, respectively. Cocultivation of epithelial cells containing HIV-1 with activated peripheral blood mononuclear cells and CD4+ T lymphocytes led to the disruption of epithelial cortical actin and spread of virus from epithelial cells to lymphocytes. Treatment of epithelial cells with proinflammatory cytokines tumor necrosis factor-alpha and interferon gamma also induced reorganization of cortical actin and release of virus. Inhibition of MVB formation by small interfering RNA (siRNA)-mediated silencing of its critical protein hepatocyte growth factor-regulated tyrosine kinase substrate (Hrs) expression reduced viral sequestration in epithelial cells and its transmission from epithelial cells to lymphocytes by ~60-70%. Furthermore, inhibition of vacuole formation of epithelial cells by siRNA-inactivated rabankyrin-5 expression also significantly reduced HIV-1 sequestration in epithelial cells and spread of virus from epithelial cells to lymphocytes. Interaction of the intercellular adhesion molecule-1 of epithelial cells with the function-associated antigen-1 of lymphocytes was important for inducing the release of sequestered HIV-1 from epithelial cells and facilitating cell-to-cell spread of virus from epithelial cells to lymphocytes. This mechanism may serve as a pathway of HIV-1 mucosal transmission.
authors.affiliation: Department of Medicine, University of California-San Francisco, San Francisco, California, United States of America.
authors.forename: Aizezi
authors.initials: A
authors.lastname: Yasen
authors.affiliation: Department of Medicine, University of California-San Francisco, San Francisco, California, United States of America.
authors.forename: Rossana
authors.initials: R
authors.lastname: Herrera
authors.affiliation: Department of Otolaryngology, University of California-San Francisco, San Francisco, California, United States of America.
authors.forename: Kristina
authors.initials: K
authors.lastname: Rosbe
authors.affiliation: Department of Medicine, University of California-San Francisco, San Francisco, California, United States of America.
authors.forename: Kathy
authors.identifier: 0000-0003-3253-9361
authors.initials: K
authors.lastname: Lien
authors.affiliation: Department of Medicine, University of California-San Francisco, San Francisco, California, United States of America.
authors.forename: Sharof M
authors.identifier: 0000-0002-3743-4334
authors.initials: SM
authors.lastname: Tugizov
mesh_terms: D015153:Blotting, Western; D015496:CD4-Positive T-Lymphocytes / Q000821:virology*; D002584:Cervix Uteri / Q000821:virology; D018920:Coculture Techniques; D003713:Dendritic Cells / Q000821:virology; D004847:Epithelial Cells / Q000821:virology*; D005260:Female; D005455:Fluorescent Antibody Technique; D052816:Foreskin / Q000821:virology; D015658:HIV Infections / Q000635:transmission*; D015497:HIV-1; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000821:virology; D008264:Macrophages / Q000821:virology; D008297:Male; D009092:Mucous Membrane / Q000821:virology*; D014066:Palatine Tonsil / Q000821:virology; D057900:Transcytosis / Q000502:physiology*