Up‐regulated cytokine‐inducible SH2‐containing protein expression in allergen‐stimulated T cells from hen's egg‐allergic patients

Summary Background Although changes in the fine balance of allergen‐specific T cells are crucial in the pathogenesis of allergic diseases, their roles in the allergic reaction to hen's eggs (HE) have not yet been fully analysed. Objective Using microarray technology, allergen‐stimulated T cells from HE‐allergic children were analysed to identify genes that are specifically up‐regulated in these cells. Methods RNA from CD4 + CD14 − cells, fractionated from allergen‐stimulated peripheral mononuclear cells, was analysed using a whole ‐genome microarray and real‐time RT‐PCR. The protein expression of selected genes was ascertained by flow cytometry. Results In microarray analyses of allergen‐stimulated T cells, 43 genes were up‐regulated in HE‐allergic children but not in non‐HE‐allergic children. Among these, up‐regulation of three genes, cytokine ‐inducible SH2‐containing protein (CISH), nuclear factor of κ light polypeptide gene enhancer in B‐cell inhibitor Z (NFKBIZ) and B‐cell CLL/lymphoma 2 (BCL2), was confirmed by real‐time quantitative RT‐PCR. CISH, but not NFKBIZ or BCL2, showed a significantly higher ratio of antigen‐stimulated cell transcription over unstimulated cells in HE‐allergic than in non‐HE‐allergic children ( P <0.01). Flow‐cytometric analysis revealed that the percentage of CD25 + CISH + cells in CD4 + cells from patients with HE allergy was significantly higher than that in controls ( P <0.01). The expression level of CISH was significantly higher in IL‐4 + Th2 cells than in IFN‐γ + Th1 cells. Conclusion We noted that CISH expression in allergen‐stimulated CD4 + T cells from HE‐allergic patients was significantly increased in both mRNA and protein levels compared with that from non‐HE‐allergic children.