title: Inhibition of cytotoxic T cell development by transforming growth factor beta and reversal by recombinant tumor necrosis factor alpha.
abstract: The immunoregulatory effects of transforming growth factor beta (TGF-beta) and recombinant murine tumor necrosis factor alpha (rMuTNF-alpha) on CTL generation and activity were examined. The results demonstrate that TGF-beta, in a dose-dependent manner, inhibited CTL generation but not CTL activity. The inhibitory effects were detected only when TGF-beta was added within the first 48 h of the MLC. Little activity was seen when it was added thereafter, including the addition of TGF-beta to the cytotoxicity assay. The production of TNF-alpha, which occurs during early phases of the MLC and which is inhibited in the presence of TGF-beta, appears to have an important regulatory role, as altering the levels of TNF-alpha in an MLC can significantly influence CTL development. The inhibitory effects of TGF-beta on the MLC can be significantly reversed by the addition of rMuTNF-alpha to the cultures. These results demonstrate that TGF-beta can inhibit MLC and subsequent CTL generation at early stages of the reaction, and such inhibition may involve the suppression of TNF-alpha production.
mesh_terms: D000818:Animals; D000906:Antibodies; D005260:Female; D007700:Kinetics; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D010455:Peptides / Q000494:pharmacology*; D011994:Recombinant Proteins / Q000494:pharmacology*; D013602:T-Lymphocytes, Cytotoxic / Q000166:cytology* / Q000187:drug effects; D015291:Transforming Growth Factors; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
chemical_list: D000906:Antibodies; D010455:Peptides; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha; D015291:Transforming Growth Factors