Interleukin-1 from baboon peripheral blood monocytes: altered response to endotoxin (lipopolysaccharide) and Staphylococcus aureus stimulation compared with human monocytes.

The baboon Papio ursinus does not elicit a febrile response upon injection with endotoxin, but fever is produced when injected with Staphylococcus aureus particles (Zurowsky, Y., H. Laburn, D. Mitchell, Can. J. Physiol. Pharmacol. 65, 1402-1407 (1987)). We address the question whether baboon peripheral blood monocytes produce interleukin-1 (IL-1) when stimulated with endotoxin or S. aureus particles in culture. Results show that little IL-1 biological activity was produced from endotoxin-stimulated baboon peripheral blood monocytes, compared with S. aureus-stimulated cells. Measurements of IL-1 beta by radioimmunoassay supported these data. This is contrary to data from human monocytes, which show greater sensitivity to endotoxin. Examination of IL-1 beta mRNA from endotoxin-stimulated and S. aureus-stimulated baboon monocytes, however, showed that more mRNA for IL-1 beta was present in endotoxin-stimulated monocytes than in cells stimulated with S. aureus. This illustrates the possibility that the production and/or the secretion of IL-1 beta is not as efficient in baboon monocytes as it is in human monocytes.