INTERLEUKIN-1 RECEPTOR MESSENGER-RNA EXPRESSION IN ACTIVATED BOVINE LEUKOCYTES IN-VITRO

Interleukin-1 (IL-1) is a key player in inflammation and the immune re sponse. To better understand the complex interactions of IL-1 and its receptors in inflammation, we need to investigate how type I and type II IL-1 receptors (IL-1RI and IL-1RII) are regulated by cytokines and other mediators. Using semiquantitative reverse transcriptase PCR and Northern analysis, we examined the regulation of IL-1RI and IL-1RII mR NA levels in bovine polymorphonuclear leukocytes (PMNs) (i.e., neutrop hils) and peripheral blood mononuclear cells (PBMCs) in vitro. IL-1RI mRNA levels were up-regulated in PBMCs by recombinant bovine IL-1 beta (rBoIL-1 beta), recombinant bovine granulocyte-macrophage colony-stim ulating factor (rBoGM-CSF), rBoIL-4, recombinant bovine gamma interfer on (rBoIFN-gamma), and dexamethasone. IL-1RI mRNA was increased in bov ine PMNs exposed to rBoGM-CSF, rBoIL-4, and dexamethasone but was down -regulated by rBoIL-1 beta and rBoIFN-gamma. IL-1RII mRNA was increase d in bovine PBMCs and PMNs after exposure to rBoIL-1 beta, rBoGM-CSF, rBoIL-4, and dexamethasone. In contrast, rBoIFN-gamma down-regulated t he expression of bovine IL-1RII mRNA in PBMCs. These findings suggest that the expression of bovine IL-1RI and IL-1RII mRNAs is regulated di fferently by certain soluble stimuli (e.g., IFN-gamma) in PMNs and PBM Cs.