RESUMEN
Interleukin (IL)-2 and IL-15 receptor ß (IL-2/15Rß, CD122) play important roles in signal transduction for biological functions of IL-2 and IL-15. We found that ducks possess three different IL-2/15Rß transcripts, a conventional form (duIL-2/15Rß) and two variants. Comparisons between the cDNA and genomic sequences revealed that the two variants, duIL-2/15Rß-d7 and duIL-2/15Rß-d9, were novel spliced transcripts resulting from skipping exons 7 and 9, respectively. Expression profiles of duIL-2/15Rß and its isoforms were examined in healthy tissues, concanavalin A (ConA)-stimulated splenic lymphocytes and in livers and spleens of Riemerella anatipestifer-infected ducks using quantitative real-time PCR (qRT-PCR). Generally, duIL-2/15Rß-d9 expression was undetectable in healthy tissues, ConA-activated samples, and R. anatipestifer-infected ducks. Expression levels of duIL-2/15Rß transcript were relatively high to moderate in all healthy tissues tested, while duIL-2/15Rß-d7 expression was low. Compared to untreated controls, expression levels of duIL-2/15Rß were elevated in ConA-activated splenic lymphocytes and in livers on day 7 in R. anatipestifer-infected ducks, while duIL-2/15Rß-d7 expression was unchanged. Additionally, COS-7 cells transfected with duIL-2/15Rß, duIL-2/15Rß-d7, or duIL-2/15Rß-d9 constructs generated 73 kilodalton (kDa), 31kDa, and 40kDa proteins, respectively. This study identified three different IL-2/15Rß transcripts, including two isoforms generated by alternative splicing and their gene expression patterns in stimulated conditions.