IDENTIFICATION OF AN ALTERNATIVELY SPLICED TRANSCRIPT OF EQUINE INTERLEUKIN-1-BETA

Using lipopolysaccharide (LPS)-stimulated equine peripheral blood mono nuclear cell (PBMC) cDNA as a template, we performed polymerase chain reaction (PCR) amplification with equine interleukin-1 beta (IL-1 beta ) specific primers. Electrophoresis of the PCR product on agarose gel revealed an additional smaller fragment that hybridized with an equine IL-1 beta cDNA probe. Sequencing of this fragment demonstrated that i t was shorter than normal equine IL-1 beta cDNA by 162 nucleotides, wh ich corresponded to exon 5 of the human and murine IL-1 beta genes. Th e deletion of 162 nucleotides did not result in a frame shift but spli ced out the putative exon 5 of the IL-1 beta gene which includes the c leavage site for the IL-1 beta converting enzyme (ICE) in human and mu rine IL-1 beta. Expression of the alternatively spliced IL-1 beta tran script in PBMC was also detected after stimulation with other compound s. These results clearly indicate the existence of an alternatively sp liced IL-1 beta transcript in equine PBMC.