Regulation of interleukin 1 production by alpha and beta interferons: evidence for both direct and indirect enhancement

In this paper, the influence of interferons alpha + beta (IFN alpha + beta) on the levels of interleukin-1 (IL-1) produced by murine peritoneal exudate macrophages following subsequent stimulation with lipopolysaccharide (LPS), colony-stimulating factor-1 (CSF-1), or both was investigated. The results indicate that preincubation with IFN alpha + beta enhances IL-1 production in response to CSF-1 as well as to LPS. Moreover, prior exposure to IFN alpha + beta enhanced the apparently synergistic production of IL-1 in response to the two stimuli combined. Lastly, IFN alpha + beta in dosages exceeding 1,000 u/ml appeared to directly stimulate IL-1 production by exudate macrophages. Direct and augmented stimulation of IL-1 production by IFN alpha + beta could be neutralized by addition of highly specific anti-IFN alpha + beta antiserum. The significance of these findings in terms of the reported inflammatory and pyrogenic effects of IFN is discussed.