The intestine was cut into 0.5-cm pieces. The pieces were incubated twice in media containing 0.15 μg/ml dithiothreitol (Sigma) and stirred at 37 °C for 20 min. Supernatants were collected and the IELs were collected at the interface of 40/80% Percoll gradients (Sigma). The purified IELs were cultured at 5 × 105/2 ml/24-well-plate in the presence of Con RAD001 price A (5 μg/ml). Supernatant were collected after 3 days culture and frozen at −80 °C

for ELISA analyses. Interleukin-2 (IL-2) activity was determined using a bio-assay on IL-2 dependent CTLL-2 cells as described elsewhere [16]. Each sample was tested in duplicate. IL-2 levels are expressed as mean counts per minute (cpm). Standard deviation was below 10% when not indicated. A typical international standard curve of this assay has been referred to [17]. IFN-γ, IL-4, IL-10 and TGF-β in the supernatant of IELs cultured with Con A by day 6 were determined by Roxadustat in vitro ELISA assay (R&D Systems, Minneapolis, MN, USA) of the culture supernatant following the manufacture’s instruction. In brief, diluted capture antibody was added to each well of the ELISA plate (Costar, Cambridge, MA, USA). Plates were sealed and incubated overnight at 4 °C. Plates were washed three times with 300 μl PBS-Tween, blocked and emptied. Samples and standards were added to

triplicate wells and plates were incubated at RT for 2 h. After washing, biotinylated detection antibody was added for 60 min at RT, followed by 100 μl horseradish peroxidase avidin for 30 min at RT. TMB substrate (Merck, Darmstadt, Germany) was added to each well. After 10 min at RT 50 μl stop solution (2 N H2SO4) was added and Rolziracetam absorbance measured at a wavelength of 450 nm. Target cells were Ag85A cDNA transfected P815 cell line (kindly provided by Professor Huygen, Pasteur Research Institute, Brussels, Belgium). These cells were incubated at 37 °C with 250 μCi of 51Cr (China Institute of Atomic Energy, China) in 1 ml of 20% FCS RPMI 1640 medium for 45 min. Labeled targets were washed three times with HBSS and

resuspended in 20% FCS RPMI at 105 cells/ml. 51Cr-labeled target cells (104 cells in 100 μl) were placed into each well of 96-well plates, and 100 μl/well of each dilution of IELs as effectors was added. Plates were incubated at 37 °C for 4 h. The supernatant from each well was harvested, and the amount of 51Cr released was counted in a gamma counter. The percentage of specific lysis was calculated as [(experimental release − spontaneous release)/(100% release − spontaneous release)] × 100. All determinations of cytotoxicity were conducted in triplicate, with a minimum of three E:T cell ratios. IELs (2 × 105 per well) purified from the immunized mice were incubated for 48 h at 37 °C in 96-well round-bottom tissue culture plates (Greiner Bio-One GmbH, Frickenhausen, Germany) in the presence of Ag85A protein.