gp33-38, an early human T cell activation antigen.
We describe an activation Ag Me14/D12 that appears early after T cell activation and is absent in resting T lymphocytes. Me14/D12 is a nondisulfide-linked heterodimeric structure containing two polypeptide chains of 33,000 and 38,000 Da. The expression of Me14/D12 on resting T lymphocytes can be induced by different activation stimuli such as the lectins PHA and Con A, the phorbol ester PMA, and anti-CD3 mAb. The induction of mRNA for Me14/D12 (gp33-38) in PHA-activated T lymphocytes precedes that of IL-2R gene transcripts by more than 20 h. Me14/D12 mRNA was detectable as early as 2 h after the onset of activation and mRNA for the IL-2R only after 24 h. The surface expression of Me14/D12 was detectable between 12 and 24 h after activation and was maximal between 24 and 48 h. Several T leukemia cell lines express the Me14/D12 Ag. On Me14/D12- cell lines, PMA and IFN-gamma induced surface expression of Me14/D12. Once Me14/D12 Ag were expressed on Jurkat cells after stimulation with either PMA or IFN-gamma, the binding of mAb Me14/D12 induced the production of significant amounts of IL-2 and of Ca2+ mobilization from internal stores. Comparative biochemical studies clearly demonstrate that Me14/D12 (gp33-38) is different from the CD69 molecular complex defined by mAb MLR3 and AIM.
Carrel
S
S
Ludwig Institute for Cancer Research, Lausanne Branch, Epalinges, Switzerland.
Salvi
S
S
Isler
P
P
Rapin
C
C
Hayoz
D
D
Gallay
P
P
Giuffrè
L
L
D000911:Antibodies, Monoclonal / Q000276:immunology; D000945:Antigens, Differentiation, T-Lymphocyte / Q000276:immunology; D017252:CD3 Complex; D002460:Cell Line; D006412:Hematopoietic Stem Cells / Q000276:immunology; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology; D007526:Isoelectric Point; D015458:Leukemia, T-Cell / Q000276:immunology; D008213:Lymphocyte Activation; D008562:Membrane Glycoproteins / Q000276:immunology*; D008970:Molecular Weight; D010835:Phytohemagglutinins / Q000494:pharmacology; D011233:Precipitin Tests; D011948:Receptors, Antigen, T-Cell / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D013997:Time Factors; D014407:Tumor Cells, Cultured
D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte; D017252:CD3 Complex; D008562:Membrane Glycoproteins; D010835:Phytohemagglutinins; D011948:Receptors, Antigen, T-Cell; D007371:Interferon-gamma; D013755:Tetradecanoylphorbol Acetate