title: M5, a phosphoinositol-linked human myelomonocytic activation-associated antigen.
abstract: When investigating the previously described monoclonal antibody (MoAb) VIM-5, raised against THP1 cells and binding to human monocytes and granulocytes, we found that the antigen detected by this antibody, designated M5, becomes very strongly expressed on monocytes after overnight culture with phorbol myristate acetate (PMA) or lipopolysaccharide (LPS) but not with recombinant human interferon-gamma (rhIFN-gamma). Granulocytes stimulated with formyl-methionyl-leucyl-phenylalanine (FMLP) become negative for binding VIM-5. Immature granulocytes from bone marrow do not express M5, thus its expression on granulocytes is differentiation linked. The antigen bound by VIM-5 is sensitive to hydrolysis by phosphoinositol-specific phospholipase C (PI-PLC). The immunoprecipitated M5 antigen on monocytes is a broad band, with a peak of 50 kD (unreduced) and two bands of 53 kD and 44 kD (reduced). We have therefore detected an antigen that is upregulated on stimulated monocytes but, conversely, down-regulated on FMLP-stimulated granulocytes.
authors.affiliation: Institute for Immunology, University of Vienna, Austria.
authors.forename: S J
authors.initials: SJ
authors.lastname: Gadd
authors.forename: O
authors.initials: O
authors.lastname: Majdic
authors.forename: W
authors.initials: W
authors.lastname: Kasinrerk
authors.forename: H
authors.initials: H
authors.lastname: Stockinger
authors.forename: D
authors.initials: D
authors.lastname: Maurer
authors.forename: R
authors.initials: R
authors.lastname: Eher
authors.forename: W
authors.initials: W
authors.lastname: Knapp
mesh_terms: D015214:Antigens, Differentiation, Myelomonocytic / Q000032:analysis*; D002478:Cells, Cultured; D015536:Down-Regulation / Q000187:drug effects; D006098:Granulocytes / Q000187:drug effects / Q000276:immunology*; D006801:Humans; D008070:Lipopolysaccharides; D008970:Molecular Weight; D009000:Monocytes / Q000187:drug effects / Q000276:immunology*; D009240:N-Formylmethionine Leucyl-Phenylalanine; D011233:Precipitin Tests; D013755:Tetradecanoylphorbol Acetate; D015854:Up-Regulation / Q000187:drug effects
chemical_list: D015214:Antigens, Differentiation, Myelomonocytic; D008070:Lipopolysaccharides; D009240:N-Formylmethionine Leucyl-Phenylalanine; D013755:Tetradecanoylphorbol Acetate