title: Human immunodeficiency virus infection of monocytic and T-lymphocytic cells: receptor modulation and differentiation induced by phorbol ester.
abstract: The monocytic leukemic cell line U937 can be infected with human immunodeficiency virus type 1 (HIV-1) to become permanently infected virus producers. Uninfected U937 cells express T4 (CD4) antigen and form syncytia when mixed with HIV-1 producing cells. Anti-T4 monoclonal antibodies block syncytium formation indicating that the HIV-1 receptors on U937 cells include T4 antigen. The promyelocytic leukemic cell line HL60, while expressing only low amounts of surface T4 and not forming syncytia on exposure to HIV-1, can be infected by HIV-1 at lower efficiency than U937 and T-cell lines. 12-O-Tetradecanoylphorbol-13-acetate (TPA) treatment induces the differentiation of U937 cells into macrophages. HIV-infected U937 cells retain the ability to differentiate, though less efficiently, as shown by the appearance of monocyte/macrophage surface markers. T4 antigen on both U937 and T-cell lines is down regulated by TPA treatment. Functional receptors for HIV-1, assayed by syncytium induction and pseudotype plating, are lost concomitantly with T4 antigen following TPA treatment of U937 cells and T cells.
mesh_terms: D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface; D002454:Cell Differentiation; D002460:Cell Line; D006678:HIV / Q000502:physiology*; D006801:Humans; D008264:Macrophages / Q000166:cytology; D009000:Monocytes / Q000166:cytology / Q000382:microbiology*; D011991:Receptors, Virus / Q000187:drug effects / Q000502:physiology*; D013601:T-Lymphocytes / Q000276:immunology / Q000382:microbiology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*
chemical_list: D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface; D011991:Receptors, Virus; D013755:Tetradecanoylphorbol Acetate