SPLICE VARIANTS OF HUMAN IL-23 RECEPTOR (IL-23R) mRNA AND USE OF A DELTA9 ISOFORM IN PREDICTING INFLAMMATORY BOWEL DISEASES
There is disclosed the cloning and identification of human IL-23R splice variants caused by alternative splicing of the IL-23R mRNA in human. Alternative mRNA forms occur through skipping one, multiple full exons or partial exons, within the IL-23R gene. A total of twenty-five (25) different IL-23R transcripts were identified. A novel exon deletion (exon 9) isoform in the interleukin 23 receptor is disclosed, denoted as Δ9. The present application also describes a quantitative assay to measure different IL-23R isoform. Detection of Δ9 isoform of IL-23R is predominantly present in colon and cervical tissues. A decrease in Δ9 is observed in inflamed colon tissues in Crohn's patients. There is disclosed a method of predicting Crohn's disease by measuring Δ9 isoform of IL-23R.
1 . A method of predicting inflammation in a colon tissue in a Crohn's disease patient, comprising the steps of:
a) obtaining a biological sample from said Crohn's disease patient;
b) performing a quantitative PCR on said biological sample;
c) determining the quantitative level (Ct) of a Δ9 isoform of IL-23R having the nucleotide sequence consisting of SEQ ID NO: 6 in said biological sample based on said quantitative PCR;
d) determining the relative quantitative level (ΔCt) of said Δ9 isoform of IL-23R in said biological sample based on said Ct; and
e) predicting inflammation in said colon tissue in said Crohn's disease patients, wherein an increase in ΔCt of said Δ9 isoform of IL-23R is indicative of inflammation in a colon tissue in a Crohn's disease patient.
2 . The method of claim 1 , wherein said biological sample is whole blood or colon tissue.
3 . The method of claim 1 , wherein said quantitative PCR is a real-time PCR.
4 . The method of claim 1 , wherein step b) is performed using a forward primer and a reverse primer, said forward primer having a nucleotide sequence set forth in SEQ ID NO 31: and said reverse primer having the nucleotide sequence set forth in SEQ ID NO: 32.
5 . The method of claim 1 , wherein step b) is performed using a forward primer and a reverse primer, said forward primer having a nucleotide sequence set forth in SEQ ID NO 29: and said reverse primer having the nucleotide sequence set forth in SEQ ID NO: 30.