title: Inhibition of sphingolipid synthesis down-modulates CD4 expression by peripheral blood T lymphocytes and T lymphoma cells.
abstract: Recent studies have demonstrated that L-cycloserine, an inhibitor of sphingolipid biosynthesis, interferes with the life cycle of HIV. Experiments with human T cells and CD4+ T lymphoma cells were performed to examine possible mechanisms. L-CS selectively down-modulated CD4 expression without affecting the expression of CD3 and CD8. L-cycloserine also inhibited T cell mitogen responses without affecting IL-2 production. Membranes prepared from L-CS-treated T lymphoma cells showed changes in lipid composition that correlated with changes in membrane microviscosity. These results suggest that normal expression of CD4 may depend upon sphingolipid biosynthesis in contrast with the other CD determinants measured. Selective inhibition of CD4 by L-cycloserine together with its antiviral effects may offer a novel approach for interfering with HIV cell binding and infectivity.
authors.affiliation: Department of Microbiology & Immunology, City University of New York Medical School, 10031, USA.
authors.forename: S L
authors.initials: SL
authors.lastname: Tamma
authors.forename: S K
authors.initials: SK
authors.lastname: Sundaram
authors.forename: M
authors.initials: M
authors.lastname: Lev
authors.forename: R F
authors.initials: RF
authors.lastname: Coico
mesh_terms: D015703:Antigens, CD / Q000096:biosynthesis*; D017252:CD3 Complex / Q000096:biosynthesis; D015704:CD4 Antigens / Q000096:biosynthesis*; D016827:CD8 Antigens / Q000096:biosynthesis; D002478:Cells, Cultured; D003523:Cycloserine / Q000494:pharmacology*; D015870:Gene Expression / Q000187:drug effects; D006678:HIV / Q000187:drug effects; D006801:Humans; D007376:Interleukin-2 / Q000096:biosynthesis; D008213:Lymphocyte Activation / Q000187:drug effects; D016399:Lymphoma, T-Cell / Q000276:immunology* / Q000378:metabolism; D008560:Membrane Fluidity; D008563:Membrane Lipids / Q000378:metabolism; D010743:Phospholipids / Q000378:metabolism; D010835:Phytohemagglutinins; D013107:Sphingolipids / Q000037:antagonists & inhibitors / Q000096:biosynthesis*; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism
chemical_list: D015703:Antigens, CD; D017252:CD3 Complex; D015704:CD4 Antigens; D016827:CD8 Antigens; D007376:Interleukin-2; D008563:Membrane Lipids; D010743:Phospholipids; D010835:Phytohemagglutinins; D013107:Sphingolipids; D003523:Cycloserine