[Effect of complement on the production of tumor necrosis factor alpha by human leukocytes with culture supernatants of clinical isolates of Staphylococcus aureus].

Induction of tumor necrosis factor alpha (TNF-alpha) of human leukocytes by overnight culture supernatants of Staphylococcus aureus (S. aureus) (CS) (4 strains) and then the effect of the complement on production of TNF alpha by the treated cells were examined. One-tenth diluted solution of CS was added to Heparinized blood and was incubated for 6 hrs at 37 C in a 5% CO-air humidified incubator. TNF alpha level in the plasma was measured by ELISA. The level in the plasma was different in different CS. The induction of TNF alpha was not found in EDTA-added blood but was found in the EGTA-added them treated with CS, though different levels were showed. Western blotting assay of these plasma samples without EDTA-added blood found the presence of both C5a and C3a. Neither C5a and C3a was found in Heparinized blood treated with a relative concentration to TSST-1, enterotoxin C and alpha (alpha) homolysin contained in CS. Mixture of these toxins induced only 1/6.5 of the TNF alpha amount obtained with the CS. Human leukocytes isolated by Mono.-Poly. resolving solution were cultured with CS in RPMI 1640 medium with or without 10% fresh or heated serum. Production of TNF alpha by the isolated leukocytes was not found under the condition of serum free. But it was found in the presence of fresh serum and also in the presence of heated serum. The addition of CS to RPMI 1640 containing heated serum did not occur naturally in the production of C5a. These results suggest that there is a difference in TNF alpha inductivility to human leukocytes in each strain and that other bacterial components without TSST-1, SEC and alpha-hemolysin are more important to induce TNF alpha. Serum may be necessary to produce TNF alpha by CS-treated cells as a source of factor(s) to interact with bacterial components rather than a source of complement.