| Literature DB >> 16133992 |
Christina S Hirsch1, John L Johnson, Alphonse Okwera, Richard A Kanost, Mianda Wu, Pierre Peters, Mathew Muhumuza, Harriet Mayanja-Kizza, Roy D Mugerwa, Peter Mugyenyi, Jerrold J Ellner, Zahra Toossi.
Abstract
The role of TGF-beta TNF-alpha FasL and Bcl-2 in apoptosis of CD4 T-cells during active TB was studied. Coculture of PBMC from TB patients with neutralizing antibodies to TGF-beta or TNF-alpha decreased spontaneous (P < or = 0.05) and MTB-induced (P < or = 0.02) T-cell apoptosis by 50-90%, but effects were not additive. Interestingly, only levels of TGF-beta in supernatants correlated with rates of spontaneous and MTB-induced apoptosis. FasL surface and mRNA expression were higher in unstimulated and MTB-stimulated PBMC from patients than controls, and neutralization of FasL abrogated apoptosis of T-cells from patients only. Intracellular Bcl-2 protein was lower among unstimulated CD4 T-cells from patients than those from controls (P < or = 0.02), and MTB stimulation reduced intracellular Bcl-2 content in CD4 T-cells from patients only (P < or = 0.001). These findings may indicate that, during TB, predisposition of CD4 T-cells to apoptosis may involve both low expression of Bcl-2, and excessive expression of TGF-beta TNF-alpha and FasL.Entities:
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Year: 2005 PMID： 16133992 DOI： 10.1007/s10875-005-4841-4
Source DB: PubMed Journal: J Clin Immunol ISSN： 0271-9142 Impact factor: 8.317