Triggering of target of an antiproliferative antibody-1 (TAPA-1/CD81) up-regulates the release of tumour necrosis factor-alpha by the EBV-B lymphoblastoid cell line JY.
Target of an antiproliferative antibody-1 (TAPA-1/CD81) has been shown to be non-covalently associated to HLA-DR antigens on the cell surface of B cells. In this study the authors report that triggering of CD81 by MoAb 5A6 or 1D6 significantly (P < 0.05) up-regulates the release of tumour necrosis factor-alpha (TNF-alpha) by the Epstein-Barr virus-positive (EBV)-B lymphoblastoid cell line JY. The accumulation of TNF-alpha in the culture medium of JY cells incubated with either anti-CD81 MoAb was found to be dose-dependent and similar to that obtained following crosslinking of HLA-DR antigens with MoAb L243. The effect of the combination of anti-CD81 and anti-HLA-DR MoAb on the release of TNF-alpha by JY cells was not synergistic or additive. In addition, the combination of anti-CD81 and anti-HLA-DR MoAb did not affect proliferation and homotypic aggregation of JY cells induced by each MoAb used alone. Both anti-CD81 or anti-HLA-DR MoAb induced protein tyrosine phosphorylation. However, different cytoplasmic proteins were phosphorylated following triggering of either molecule. Taken together, the data demonstrate that CD81 and HLA-DR antigens induce similar effector phenomena in the regulation of TNF-alpha release, homotypic aggregation and inhibition of JY cell proliferation.
Altomonte
M
M
Advanced Immunotherapy Unit, INRCCS-CRO, Department of Sciences and Biomedical Technologies, University of Udine, Italy.
Montagner
R
R
Pucillo
C
C
Maio
M
M
D000911:Antibodies, Monoclonal / Q000494:pharmacology*; D015703:Antigens, CD / Q000276:immunology* / Q000502:physiology*; D001402:B-Lymphocytes / Q000201:enzymology / Q000276:immunology / Q000378:metabolism*; D002449:Cell Aggregation / Q000276:immunology; D002455:Cell Division / Q000276:immunology; D002461:Cell Line, Transformed; D003593:Cytoplasm / Q000201:enzymology / Q000378:metabolism; D004357:Drug Synergism; D006684:HLA-DR Antigens / Q000276:immunology / Q000502:physiology; D004854:Herpesvirus 4, Human / Q000276:immunology*; D006801:Humans; D008565:Membrane Proteins; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D060225:Tetraspanin 28; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*; D015854:Up-Regulation / Q000187:drug effects / Q000276:immunology*
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; C554798:CD81 protein, human; D006684:HLA-DR Antigens; D008565:Membrane Proteins; D060225:Tetraspanin 28; D014409:Tumor Necrosis Factor-alpha; D011505:Protein-Tyrosine Kinases