E M Glare1, M Divjak, J M Rolland, E H Walters. 1. Department of Respiratory Medicine, Alfred Hospital and Monash University Medical School, Melbourne, Victoria, Australia.
Abstract
BACKGROUND: The human IL4 gene, has been shown to express the alternatively spliced messenger (m)RNA IL-4delta2. IL-4delta2 is missing the entire sequence from exon 2 and has been identified as an IL-4 receptor antagonist. OBJECTIVE: We sought to distinguish IL-4 and IL-4delta2 mRNA in respiratory tract tissue for the first time. METHODS: A novel competitive PCR assay was established with primers designed on either side of the alternative splice junction of the IL4 gene, allowing the simultaneous quantitation of both IL-4 and IL-4delta2 mRNA from one reaction. RESULTS: IL-4 and IL-4delta2 were differentially expressed in 4 nasal polyps. No difference was seen in endobronchial biopsy specimens for IL-4 mRNA expression between control subjects (median, 2.8 x 10(2) copies/microg RNA; range, 0-3.7 x 10(3) copies/microg RNA) and asthmatic subjects (median, 1.4 x 10(2) copies/microg RNA; range, 0-4.7 x 10(2) copies/microg RNA). However, significantly more asthmatic subjects (6 of 9) than control subjects (1 of 7) expressed IL-4delta2 (P =. 036). Expression of IL-4 variants was unaffected by atopic status. CONCLUSIONS: Given that IL-4delta2 is an IL-4 receptor antagonist, these results indicate that it is crucial to be able to distinguish IL-4delta2 from IL-4 when assessing IL4 gene expression. Increased expression of IL-4delta2 in stable asthmatic subjects suggests that the balance of IL-4 and IL-4delta2 may modulate asthmatic inflammation.
BACKGROUND: The humanIL4 gene, has been shown to express the alternatively spliced messenger (m)RNA IL-4delta2. IL-4delta2 is missing the entire sequence from exon 2 and has been identified as an IL-4 receptor antagonist. OBJECTIVE: We sought to distinguish IL-4 and IL-4delta2 mRNA in respiratory tract tissue for the first time. METHODS: A novel competitive PCR assay was established with primers designed on either side of the alternative splice junction of the IL4 gene, allowing the simultaneous quantitation of both IL-4 and IL-4delta2 mRNA from one reaction. RESULTS:IL-4 and IL-4delta2 were differentially expressed in 4 nasal polyps. No difference was seen in endobronchial biopsy specimens for IL-4 mRNA expression between control subjects (median, 2.8 x 10(2) copies/microg RNA; range, 0-3.7 x 10(3) copies/microg RNA) and asthmatic subjects (median, 1.4 x 10(2) copies/microg RNA; range, 0-4.7 x 10(2) copies/microg RNA). However, significantly more asthmatic subjects (6 of 9) than control subjects (1 of 7) expressed IL-4delta2 (P =. 036). Expression of IL-4 variants was unaffected by atopic status. CONCLUSIONS: Given that IL-4delta2 is an IL-4 receptor antagonist, these results indicate that it is crucial to be able to distinguish IL-4delta2 from IL-4 when assessing IL4 gene expression. Increased expression of IL-4delta2 in stable asthmatic subjects suggests that the balance of IL-4 and IL-4delta2 may modulate asthmatic inflammation.
Authors: Irina G Luzina; Virginia Lockatell; Sachin Lavania; Edward M Pickering; Phillip H Kang; Yulia N Bashkatova; Sergey M Andreev; Sergei P Atamas Journal: Cytokine Date: 2012-01-15 Impact factor: 3.861
Authors: Irina G Luzina; Virginia Lockatell; Nevins W Todd; Achsah D Keegan; Jeffrey D Hasday; Sergei P Atamas Journal: Immunology Date: 2011-01-10 Impact factor: 7.397
Authors: Irina G Luzina; Achsah D Keegan; Nicola M Heller; Graham A W Rook; Terez Shea-Donohue; Sergei P Atamas Journal: J Leukoc Biol Date: 2012-07-10 Impact factor: 4.962