Biosynthesis of interleukin-I beta at inflammatory site in rabbits: kinetics and producing cells

Biosynthesis of interleukin-I beta (IL-I beta) by inflammatory peritoneal exudate cells (PEC) was studied in terms of biological activity (thymocyte co-mitogenic assay), IL-I beta mRNA expression (cytoplasmic slot blot analysis) and detection of immunoreactive IL-I beta molecule (immunocytochemistry). Our findings were taken to conclude that IL-I beta expression was observed only in PEC harvested from early inflammatory site and the kinetic profile of the IL-I activity during the course of the inflammation was explained by IL-I beta mRNA expression, namely de-novo synthesis by inflammatory exudate cells. With respect to a single cell level, it was definitely proved that polymorphonuclear leucocytes were the major producer of IL-I beta during the casein-induced acute inflammation in rabbits.