It appears that H(2)O(2) and NO are needed for alum-induced production of a T-helper 2 cytokine. NO also appears to be needed, whereas H(2)O(2) appeared to inhibit an alum-induced production of a T-helper 1 cytokine. These results might explain why alum is mainly a promoter of a T-helper 2 response.

Coley's Mixed Bacterial Toxin (MBT) used to treat cancer patients, is thought to be a modulator of a number of cytokines. In this study the effects of the MBT supernatant and bacterial lipopolysaccharide (LPS) on serum levels of tumor necrosis factor-α (TNF-α), interleukin-12 (IL-12), and vascular endothelial growth factor (VEGF) were determined. MBT was prepared, centrifuged and the supernatant was dialyzed. The protein content of the dialysate was determined by the Bradford assay and SDS-PAGE. A portion of the dialysate was heated to denature proteins. Groups of mice were given intraperitoneal injections of MBT, dialysate or heated dialysate, LPS, RPMI, or were left untreated. Serum levels of TNF-α, IL-12 and VEGF were determined at 2, 4, and 6 hours post-injection by ELISA. The dialysate contained 9% protein and SDS-PAGE revealed only one band (17KDa). Unheated or heated dialysate increased the levels of TNF-α and IL-12. Heated dialysate decreased VEGF levels. LPS caused an increase in TNF-α and IL-12, and a decrease in VEGF levels. Activity was present in the MBT and both heated and unheated dialysate. Heating of fractions enhanced activity, suggesting that active sites were exposed or inhibitory factors were inactivated by heat. It appears that LPS could be one of the active constituents of MBT.