Neutralizing monoclonal antibodies to human immunodeficiency virus type 1 do not inhibit viral transcytosis through mucosal epithelial cellsChomont, N.Hocini, H.Gody, J. C.Bouhlal, H.Becquart, PierreKrief Bouillet, C.Kazatchkine, M.Belec, L.HIV 1HEC 1transcytosisneutralizationHIV-1 transcytosis has been proposed as a potential mechanism allowing the virus to cross the epithelium during mucosal transmission. Epitopes of the HIV-1 envelope involved in this process have not been identified yet. Here, we assessed a large panel of HIV neutralizing antibodies recognizing well-characterized epitopes of the HIV-1 envelope for their ability to block HIV-1 transcytosis across a confluent epithelial monolayer. We found that all of the 13 HIV-1-specific monoclonal antibodies tested in the present study, including the three broadly neutralizing antibodies 2F5. 2G12 and lgG1bI2, lacked the ability to inhibit transcytosis of cell-free and cell-associated R5- as X4-tropic HIV-1 across a tight and polarized monolayer of HEC-1 epithelial cells. In contrast, anti-gp 160 polyclonal antibodies purified from serum or breast milk of HIV-1-infected individuals potently inhibited HIV-1 transcytosis. Furthermore, polymeric S-IgA exhibited similar ability to inhibit transcytosis compared to IgG despite their lower anti-gp 160 specific activity. Together, these results demonstrate that the major neutralizing envelope epitopes of HIV-1 are not involved in HIV-1 transcytosis, and suggest that surface agglutination of virus particles may participate to the blocking effect observed with both polyclonal and polymeric anti-gp 160 immunoglobulins.2007texthttp://www.documentation.ird.fr/hor/fdi:010040892oai:ird.fr:fdi:010040892Chomont N., Hocini H., Gody J. C., Bouhlal H., Becquart Pierre, Krief Bouillet C., Kazatchkine M., Belec L. Neutralizing monoclonal antibodies to human immunodeficiency virus type 1 do not inhibit viral transcytosis through mucosal epithelial cells. Virology, 2007, 370 (2), p. 246-254.