Triggering of the alternative pathway of human T cell activation involves members of the T 200 family of glycoproteins.
The present report describes functional characteristics of a monoclonal antibody (mAb), TA/211, which is reactive with a common determinant of the human CD45 molecules. When added to purified testing human T cells, TA/211, which is itself not mitogenic, leads to a strong proliferative response in combination with submitogenic concentrations of anti-T11(2) plus anti-T11(3) mAb. Interestingly, while amplifying anti-CD2-mediated immune responses, T cell activation induced through triggering of the CD3 molecule is not enhanced by TA/211, indicating that the triggering signal provided through CD45 is restricted to alternative pathway activation. Employing T cell subsets negatively selected for the expression of CD45R molecules defined by the mAb anti-2H4 or UCHL1, respectively, it is demonstrated that resting T cells expressing the 2H4 molecules proliferate much stronger to TA/211 than the UCHL1+ T cell subset. Together with the finding that the 2H4+ T cell subset can be activated by the concomitant binding of anti-CD2 antibodies plus anti-2H4, these data strongly suggest that the high molecular weight species of CD45 expressed by unprimed T cells are themselves involved in T cell activation via the alternative pathway.
Schraven
B
B
Abteilung für Angewandte Immunologie, Deutsches Krebsforschungszentrum, Heidelberg, FRG.
Roux
M
M
Hutmacher
B
B
Meuer
S C
SC
D000276:Adjuvants, Immunologic / Q000502:physiology; D000818:Animals; D000911:Antibodies, Monoclonal / Q000502:physiology; D000943:Antigens, Differentiation / Q000276:immunology; D000945:Antigens, Differentiation, T-Lymphocyte / Q000276:immunology*; D018801:CD2 Antigens; D004306:Dose-Response Relationship, Immunologic; D000939:Epitopes / Q000276:immunology; D005260:Female; D006649:Histocompatibility Antigens / Q000276:immunology; D017493:Leukocyte Common Antigens; D008213:Lymphocyte Activation; D008562:Membrane Glycoproteins / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008970:Molecular Weight; D011971:Receptors, Immunologic / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*
D000276:Adjuvants, Immunologic; D000911:Antibodies, Monoclonal; D000943:Antigens, Differentiation; D000945:Antigens, Differentiation, T-Lymphocyte; D018801:CD2 Antigens; D000939:Epitopes; D006649:Histocompatibility Antigens; D008562:Membrane Glycoproteins; D011971:Receptors, Immunologic; D017493:Leukocyte Common Antigens