Sialophorin, a surface sialoglycoprotein defective in the Wiskott-Aldrich syndrome, is involved in human T lymphocyte proliferation.
The mAb L10 was used to determine the distribution and the function of sialophorin, the heavily glycosylated surface molecule that is deficient/defective in lymphocytes of patients with the X-linked immunodeficiency Wiskott-Aldrich syndrome. Dual-parameter FACS analysis indicated that sialophorin is expressed on CD4+ and CD8+ lymphocytes, on a subpopulation of peripheral blood B lymphocytes, on all thymocytes, and on a subpopulation of bone marrow cells. Functional studies demonstrated that L10 mAb stimulates the proliferation of peripheral blood T lymphocytes as measured by stimulation of [3H]thymidine incorporation. The time course and magnitude of increased [3H]thymidine incorporation by T lymphocytes in response to L10 mAb paralleled that induced by anti-CD3 mAb. Effective stimulation was dependent on the presence of monocytes and the Fc portion of L10 mAb. Stimulation of lymphocytes by L10, like stimulation by anti-CD3 mAb, involves increased expression of 4F2, HLA-DR, and IL-2-R. These observations suggest that sialophorin functions in T cell activation.
D000911:Antibodies, Monoclonal / Q000494:pharmacology; D015703:Antigens, CD; D006801:Humans; D051917:Leukosialin; D008213:Lymphocyte Activation / Q000187:drug effects; D008212:Lymphocyte Depletion; D008214:Lymphocytes / Q000276:immunology; D008565:Membrane Proteins / Q000172:deficiency; D009000:Monocytes / Q000502:physiology; D012795:Sialoglycoproteins / Q000378:metabolism / Q000502:physiology*; D014018:Tissue Distribution; D014923:Wiskott-Aldrich Syndrome / Q000097:blood
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D051917:Leukosialin; D008565:Membrane Proteins; C465014:SPN protein, human; D012795:Sialoglycoproteins