Expression and role in apoptosis of the alpha- and beta-chains of the IFN-gamma receptor on human Th1 and Th2 clones
| Autor: | F, Novelli, M M, D'Elios, P, Bernabei, L, Ozmen, L, Rigamonti, F, Almerigogna, G, Forni, G, Del Prete |
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| Rok vydání: | 1997 |
| Předmět: | |
| Zdroj: | The Journal of Immunology. 159:206-213 |
| ISSN: | 1550-6606 0022-1767 |
| DOI: | 10.4049/jimmunol.159.1.206 |
| Popis: | The mRNA and protein expression of the alpha- and beta-chains of IFN-gammaR were evaluated on a panel of human Th1 and Th2 clones. When cultured in IL-2-conditioned medium, both types of clones expressed mRNA for the alpha- and beta-chains, and both chains were present in the cytoplasm. Membrane expression of the alpha-chain was higher on Th2 than on Th1, whereas the beta-chain was poorly expressed on both types but increased following IL-2 withdrawal or PHA stimulation. In addition, both types of clones overexpressed MHC class I glycoproteins following IFN-gammaR triggering by exogenous IFN-gamma, although the kinetics was slower in Th1, and this exposure induced mRNA for IRF-1. When their TCR was triggered in the absence of APC, Th1 only underwent apoptosis. This activation-induced apoptosis was prevented by blocking of the alpha-chain or by IFN-gamma neutralization. Addition of IFN-gamma triggered the apoptosis of Th2 clones. Apoptosis of both types of clones was mediated by autocrine or exogenous IFN-gamma through the up-regulation of Fas-L expression, since anti-IFN-gammaR alpha mAb inhibited its expression on Th1 and exogenous IFN-gamma increased its expression on Th2. These results indicate that activated human Th1 and Th2 lymphocytes express IFN-gammaR alpha- and beta-chains and are both sensitive to signals provided by IFN-gamma. Data also suggest that IFN-gamma is critical for switching off their responses. |
| Databáze: | OpenAIRE |
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