Human sera and culture supernatants from human tumors and diploid fetal fibroblasts suppress tumor necrosis factor secretion in vitro.
J Leukoc Biol
; 46(1): 34-40, 1989 Jul.
Article
em En
| MEDLINE
| ID: mdl-2499648
ABSTRACT
Human sera and culture supernatants from human tumors and diploid fetal fibroblasts suppressed peripheral blood leukocyte secretion of tumor necrosis factor (TNF). The suppressive activities of all three fluids had similar characteristics each was heat and acid stable, removed by adsorption on immobilized lectins, and abrogated the stimulatory effect of interferon-gamma. Inhibition of leukocyte TNF secretion was observed only when either serum or conditioned medium was added to leukocytes at the initiation of culture; delaying the addition by 2 h failed to suppress cytokine secretion. Suppression by all fluids was also found to be reversible by washing cells free of suppressive activity. Although serum, tumor, and fibroblast culture supernatants inhibited cytokine secretion, they failed to alter the cytotoxic activity of recombinant human TNF on murine L929 cells. This study suggests that factors which can inhibit TNF secretion are present in human blood and are secreted by both fibroblasts and tumor cells. These suppressive factors may play an important role in the regulation of TNF secretion and cytokine homeostasis.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fator de Necrose Tumoral alfa
Limite:
Adult
/
Animals
/
Humans
Idioma:
En
Revista:
J Leukoc Biol
Ano de publicação:
1989
Tipo de documento:
Article