Neutrophils, but not monocytes or microglia, degraded interleukin-1 beta in vitro

Interleukin-1 beta (IL-1 beta) is a key regulatory component of host defense systems, and it is involved in physiological regulation including several central nervous system functions like fever and sleep. Nevertheless, little is known about how IL-1 beta is degraded. Based on their protease secreting capabilities, the ability of microglia, monocytes, and neutrophils to degrade IL-1 beta was studied. Neutrophil cultures degraded IL-1 beta, whereas microglia and monocyte cultures did not. The degradation if IL-1 beta by neutrophils may constitute a downregulation mechanism for IL-1 beta.