{'fraction_non_alphanumeric': 0.04338549075391181, 'fraction_numerical': 0.01422475106685633, 'mean_word_length': 5.171052631578948, 'pattern_counts': {'":': 0, '<': 2, '<?xml version=': 0, '>': 1, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Transforming growth factor-beta 1 inhibits synthesis of cytokines in endotoxin-stimulated human whole blood.

OBJECTIVE
To determine the potency of transforming growth factor-beta (TGF-beta) for inhibiting proinflammatory cytokine synthesis in endotoxin-stimulated human whole blood.


DESIGN
Endotoxin-stimulated whole blood from healthy volunteers as an ex vivo model of endotoxemia was incubated with different concentrations of TGF-beta 1. Cytokine levels in plasma with a bioassay (for tumor necrosis factor alpha) or an enzyme-linked immunosorbent assay (for interleukin [IL]-1 beta and IL-6), messenger RNA (mRNA) expression with northern blotting, and protein levels with Western blotting were determined.


RESULTS
High TGF-beta 1 concentrations (> 100 pg/mL) inhibited (P < .05) secretion of tumor necrosis factor alpha, IL-1 beta, and IL-6 into lipopolysaccharide-stimulated whole blood, while low concentrations (< 50 pg/mL) were ineffective. Moreover, TGF-beta 1 inhibited mRNA expression of tumor necrosis factor alpha and IL-6 in a dose-dependent manner. In contrast, neither IL-1 beta mRNA expression nor IL-1 beta protein synthesis were attenuated by TGF-beta 1.


CONCLUSION
Transforming growth factor-beta 1, with its downregulatory effect on the synthesis and release of proinflammatory cytokines by phagocytic cells, represents an inhibitor of endotoxin-induced inflammatory reactions.