T cells infiltrating non-Hodgkin's B cell lymphomas show altered tyrosine phosphorylation pattern even though T cell receptor/CD3-associated kinases are present.
Although tumor infiltrating lymphocytes (T-TIL) from B cell non-Hodgkins lymphoma patients contain tumor-reactive T cells, they display poor proliferation and IFN-gamma production when stimulated through the TCR-CD3. To determine if there was altered signaling linked to TCR-CD3 ligation, tyrosine phosphorylation was examined in T-TIL because it represents an early and critical event in T cell activation. After stimulation with anti-CD3 Ab, Western blotting with anti-phosphotyrosine showed reduced phosphorylation in T-TIL when compared with peripheral blood-derived T cells from normal individuals. The altered phosphorylation was not due to the reduced expression of signaling elements linked to the TCR-CD3 complex. T-TIL expressed normal levels of CD3 epsilon, TCR zeta chain, and the three tyrosine kinases, p56lck (Lck), p59fyn, and ZAP-70. However, in T-TIL, anti-Lck Ab reacted with a 60-kDa protein, which appears to be the phosphorylated form of Lck. Binding of anti-Lck Ab to the 60-kDa protein was blocked by Lck peptide. In addition, anti-Lck Ab immunoprecipitated a phosphorylated 60-kDa protein from gamma-32P-labeled T-TIL that was not seen in normal resting T cells. In vitro kinase assay studies also demonstrated that TCR-CD3 engagement increased the kinase activity of Lck in normal T cells but not in T-TIL. These results suggest that although T-TIL from B cell non-Hodgkins lymphoma patients contain the signal transduction molecules associated with TCR-CD3 activation pathway, they are impaired in tyrosine phosphorylation and Lck activity, which may contribute to the functional defects of these cells.
Wang
Q
Q
Department of Immunology, Cleveland Clinic Foundation, OH 44195, USA.
Stanley
J
J
Kudoh
S
S
Myles
J
J
Kolenko
V
V
Yi
T
T
Tubbs
R
R
Bukowski
R
R
Finke
J
J
D006801:Humans; D007108:Immune Tolerance; D019860:Lymphocyte Specific Protein Tyrosine Kinase p56(lck); D016246:Lymphocytes, Tumor-Infiltrating / Q000378:metabolism*; D016393:Lymphoma, B-Cell / Q000276:immunology* / Q000473:pathology; D008565:Membrane Proteins / Q000378:metabolism; D016853:Muromonab-CD3 / Q000494:pharmacology; D009363:Neoplasm Proteins / Q000378:metabolism*; D010766:Phosphorylation; D011499:Protein Processing, Post-Translational; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D051076:Proto-Oncogene Proteins c-fyn; D017260:Receptor-CD3 Complex, Antigen, T-Cell / Q000378:metabolism*; D011948:Receptors, Antigen, T-Cell / Q000378:metabolism; D015398:Signal Transduction; D016176:T-Lymphocyte Subsets / Q000378:metabolism*; D051746:ZAP-70 Protein-Tyrosine Kinase
D008565:Membrane Proteins; D016853:Muromonab-CD3; D009363:Neoplasm Proteins; D011518:Proto-Oncogene Proteins; D017260:Receptor-CD3 Complex, Antigen, T-Cell; D011948:Receptors, Antigen, T-Cell; C054979:antigen T cell receptor, zeta chain; D011505:Protein-Tyrosine Kinases; C494957:FYN protein, human; D019860:Lymphocyte Specific Protein Tyrosine Kinase p56(lck); D051076:Proto-Oncogene Proteins c-fyn; D051746:ZAP-70 Protein-Tyrosine Kinase; C497261:ZAP70 protein, human