The remaining LP were incubated twice for 25 min at 37°C in RPMI medium containing DNAse (5 mg), collagenase A (25 mg), collagenase D (25 mg), dispase I (0.3 g) and penicillin/streptomycin (100 U/mL). Lymphocytes were then collected, passed though the cell strainer and resuspended in medium. Single-cell suspensions prepared from different organs of recipient mice were stained and analyzed on FACSCalibur or FACSCanto (Becton Dickinson, Mountain View, CA) using FlowJo software (Tree Star). For surface phenotyping of lymphocyte populations, the following fluorochrome-conjugated
or biotinylated mAbs were used: anti-CD4 (RM4-5), VX-809 research buy anti-CD25 (PC61), anti-CD3 (145-2C11) and anti-γδ TCR (GL-3) (eBioscience or BD Bioscience). For determination of intracellular cytokine production, cells were restimulated with PMA (20 ng/mL), ionomycin (1 nM) for 4 h at 37°C in the presence of BD GolgiStop™ (1:1000 dilution). Cells were then stained for surface antigens, fixed/permeabilized with Fix/Perm solution (eBioscience) and stained with anti-IFN-γ (XMG1.2), anti-IL-17A (TC11-18H10.1 or eBio17B7), anti-IL-10 (JES5-16E3), anti-IL-2 (JES6-5H4) (purchased from eBioscience or BD Bioscience). In order to determine cellular learn more proliferation in vivo, cells were stained intracellularly with anti-Ki-67 (B56)
(BD Bioscience), as described above. Colons were collected in RNAlater (Qiagen, Mississauga, ON) and frozen at −20°C until use. RNA was extracted following the TRIzol protocol (Invitrogen, Burlington, ON). Total RNA was reverse-transcribed using the cDNA Archive Kit (Applied Biosystems, Foster City, CA). Quantitative real-time PCR was performed using an ABI Prism 7900HT Sequence Detection System (Applied Biosystems) (1 PCR cycle, 95°C, 10 min; 40 PCR cycles, 60°C, 1 min, 95°C, 15 s). cDNA (10 ng total RNA) was
amplified in a reaction mix containing TaqMan Universal PCR Master Mix (Applied Biosystems) and corresponding TaqMan Gene Expression Assays (Applied Biosystems). Signals were analyzed by the ABI Prism Sequence Detection System software version Morin Hydrate 2.2 (Applied Biosystems). The comparative Ct method for relative quantification was used, whereby all threshold cycles were normalized to the expression of 18s rRNA. Cytokine expression is represented as a fold-change relative to control non-diseased mice adoptively transferred with total CD4+ T cells. For suppression assay, FACS-sorted γδ TCR+ or CD4+CD25− T cells (50×103) were plated in 96-well, flat-bottomed microtiter plates (0.2 mL) with 200×103 irradiated total splenocytes and activated with soluble anti-CD3 (1 μg/mL) and IL-2 (100 U/mL). After 12 h, 75% of the medium was subtracted from each well, and FACS-sorted CD4+CD25+ TREG cells were added with fresh medium to the co-culture at various ratios. Cells were cultured for a total of 72 h at 37°C and pulsed for the last 12 h with 0.5 uCi of 3H-thymidine to determine the extent of proliferation.