Tyrosine phosphorylation of the human T cell antigen receptor zeta-chain: activation via CD3 but not CD2.
TCR stimulation by Ag or anti-receptor antibodies in murine T cells results in the activation of two independent protein kinases, protein kinase C (PKC) and a protein tyrosine kinase. Similarly, stimulation of murine Thy-1 or Ly-6 with mAb also results in activation of both of these kinase pathways. Tyrosine phosphorylation in all cases occurs on the TCR zeta-chain. It is known that Ag and anti-receptor antibodies activate PKC in human T cells. In this study we demonstrate that mitogen or anti-CD3 antibodies activate tyrosine phosphorylation of the human TCR-zeta-chain. PMA, which activates PKC, does not result in zeta-chain tyrosine phosphorylation. Stimulation of human T cells by antibodies that bind the CD2 molecule is an alternate mode of inducing T cell proliferation. These antibodies surprisingly do not induce tyrosine phosphorylation of the zeta-chain. Thus, different methods of cellular activation can result in distinguishable patterns of receptor-mediated biochemical signaling events.
Weissman
A M
AM
Cell Biology and Metabolism Branch, National Institute of Child Health and Human Development, Bethesda, MD 20892.
Ross
P
P
Luong
E T
ET
Garcia-Morales
P
P
Jelachich
M L
ML
Biddison
W E
WE
Klausner
R D
RD
Samelson
L E
LE
D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte / Q000276:immunology*; D006801:Humans; D008213:Lymphocyte Activation; D008565:Membrane Proteins; D008970:Molecular Weight; D010766:Phosphorylation; D011233:Precipitin Tests; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D011948:Receptors, Antigen, T-Cell / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism*; D013601:T-Lymphocytes / Q000201:enzymology / Q000276:immunology / Q000378:metabolism*; D014443:Tyrosine / Q000378:metabolism
D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte; D008565:Membrane Proteins; D011948:Receptors, Antigen, T-Cell; C054979:antigen T cell receptor, zeta chain; D014443:Tyrosine; D011505:Protein-Tyrosine Kinases