Evidence that murine hematopoietic cell subset marker J11d is attached to a glycosyl-phosphatidylinositol membrane anchor.
Glycosyl-phosphatidylinositol (G-PI) has been shown to serve as membrane anchor for cell surface molecules such as Thy-1, Ly-6-controlled ThB and Qa antigens. Here, we present several lines of evidence indicating that the hematopoietic cell lineage (i.e. thymocytes, B cell subset and red blood cells) marker defined by the rat monoclonal antibody J11d is also a G-PI-linked structure. First, surface expression of the J11d-defined molecules, and that of the related antigen B2A2, was found to be specifically reduced by treatment of thymocytes and B lymphoma or hybridoma cells with excess of Staphylococcus aureus PI-specific phospholipase C; this enzyme also solubilizes a 35-40-kDa material from erythrocyte microsomal membranes corresponding to the predominant J11d-reactive red cell surface molecules. Second, Thy-1- mutants of the BW5147, T1M1, S1A or S49 murine T lymphoma cells of the complementary classes A, B, C and E (i.e. shown to be defective in the enzymatic machinery that posttranslationally modify Thy-1 molecules) also lack J11d, or express it at a very low level. Although directed at a G-PI-linked structure, the J11d monoclonal antibody, unlike other reagents to Thy-1 or Ly-6-controlled antigens, failed to induce thymocyte proliferation even in the presence of phorbol myristate acetate and cross-linker monoclonal antibody.
D000818:Animals; D000911:Antibodies, Monoclonal; D000943:Antigens, Differentiation; D001402:B-Lymphocytes / Q000276:immunology; D004912:Erythrocytes / Q000276:immunology; D006017:Glycolipids; D017261:Glycosylphosphatidylinositols; D008213:Lymphocyte Activation; D008562:Membrane Glycoproteins / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D008970:Molecular Weight; D010716:Phosphatidylinositols / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D013601:T-Lymphocytes / Q000276:immunology; D010738:Type C Phospholipases
D000911:Antibodies, Monoclonal; D000943:Antigens, Differentiation; D006017:Glycolipids; D017261:Glycosylphosphatidylinositols; D008562:Membrane Glycoproteins; D010716:Phosphatidylinositols; D010738:Type C Phospholipases