CLONING, SEQUENCING AND REGULATION OF AN MESSENGER-RNA ENCODING PORCINE INTERLEUKIN-1-BETA

Interleukin 1 (IL-1) is a cytokine that mediates a variety of immunolo gical responses. We report here the isolation of a porcine IL-1beta cD NA from an alveolar macrophage library. The complete cDNA sequence is 1458 bp in length and has an open reading frame of 803 bp, encoding a 267-amino-acid (aa) protein with an approximate molecular size of 31 k Da. The porcine IL-1beta cDNA sequence shows homologies of 82.0, 81.0, 74.0, and 74.0% with the bovine, sheep, human, and murine sequences i n the protein coding regions, respectively. Northern blot analysis rev eals a single 1.7-kb mRNA species that is differentially regulated by lipopolysaccharide, phorbol myristate acetate, and tumor necrosis fact or but is not regulated by human recombinant IL-1. Porcine IL-1beta is down-regulated by dexamethasone, polymyxin B, and IL-4 in a fashion k inetically similar to the other reported species.