In intracellular staining, cells were incubated with permealization reagents for 30 min on ice. The stained cells were analysed by flow cytometry (FACScan; BD Bioscience, San Jose, CA, USA). Isolated CD4 T cells were cultured in the presence of the specific antigen [OVA, 10 µg/ml; or bovine serum albumin (BSA) used as control] for 72 h. Brefeldin A (10 µg/ml) was added for the last 6 h. Cells were collected at the end of experiment and analysed by flow cytometry (see above). CD4+ T cells were isolated from intestinal lamina propria mononuclear cells (LPMCs), stained with carboxyfluorescein succinimidyl ester (CFSE) and cultured in the presence of irradiated splenic

dendritic cells (DCs) (T cell : 

DC = 105 : 104/well) and OVA (10 µg/ml, Romidepsin molecular weight or BSA used as control) for 4 days. The CFSE dilution assay was performed using flow cytometry. All values were expressed as the means ± standard deviation of at least three independent experiments. The values were analysed using the two-tailed unpaired Student’s t-test when data consisted of two groups or by analysis of variance (anova) when three or more groups were compared. P < 0·05 was accepted as statistically significant. The reagent information and isolation of LPMC were present in supplemental materials. The CD4+ IL-10+ IL-9+ T cells have been described recently; this subset of T cells expressed is involved in the immune inflammation [9]. As both IL-9 and IL-10 belong to Th2 cytokines, we Napabucasin postulated that antigen-specific reaction might favour the generation of IL-9+ IL-10+ T cells in individuals with skewed Th2 polarization in the body. To test this hypothesis, a Th2 inflammation mouse model was developed (Fig. 1a). As depicted in Fig. 1b–f, Th2 pattern inflammation was induced in the intestine, manifesting the drop in core temperature (Fig. 1b) of mice upon antigen challenge, increases in serum levels of OVA-specific IgE (Fig. 1c)

and histamine (Fig. 1d), and Th2 cell proliferation after exposure to the specific antigen (OVA) in culture (Fig. 1e,f). Using flow cytometry, CD4+ IL-9+ IL-10+ T cells were detected in the mice intestines (Fig. 2a,b). The frequency of this subset was less than 1% in isolated intestinal CD4+ T cells of naive mice, but was increased more than threefold in sensitized Ribonucleotide reductase mice (Fig. 2a,b). The extravasation of Mo and neutrophil in the tissue is an important feature of LPR; its initiation mechanism is incompletely understood. The finding in Fig. 1 prompted us to elucidate a possible role by which IL-9+ IL-10+ T cells contributed to Mo and neutrophil extravasation in LPR; the cytokines derived from IL-9+ IL-10+ T cells might be responsible for the process. Thus, we isolated CD4+ T cells from the small intestine of mice stained with fluorescence-labelled antibodies and they were examined using flow cytometry. The IL-9+ IL-10+ T cells in Fig.