Alteration of CD44 Expression in HIV Type 1-Infected T Cell Lines

ABSTRACT CD44 is known to interfere in HIV replication and to participate in many physiological processes such as lymphocyte binding to high endothelial venules of lymphoid tissue, lymph nodes, and mucosal endothelium. The T cell lines MOLT-4 and CEM, and CEM subclones were infected with the HIV-1 LAI strain and monitored for the expression of CD44 during the course of chronic virus production until the infected cells were at the stage of latent infection. The levels of CD44 protein expression were quantified using cell surface immunostaining and biotinylation. The maturation of CD44 molecules was evaluated by metabolic sulforadiolabeling and CD44 mRNA was visualized by Northern blot analysis. We show a downmodulation of CD44 expression in infected T cell lines and subclones. This phenomenon was most evident at the stage of latent infection. Then, CD44 molecules were undetectable at both the protein and mRNA levels in latently infected CEM cells and CEM subclones. In addition, the 97-kDa standard CD44 iso...