Supernatants of T-cell proliferation cultures were harvested at 48 h after initiation of culture. Concentrations of IFN-γ, TNF-α, IL-2, IL-4, and IL-5 were measured by mouse Th1/Th2 cytokine bead array assay (BD Bioscience) according to manufacturer’s recommendation. Thymus was obtained from 6-wk-old C57BL/6 mice, and cell suspensions

were stained for 15 min in PBS+0.5% BSA with specific mAbs against CD4-PE and CD8-FITC (BD Bioscience). After staining, cell suspensions were washed and resuspended for analysis. Flow cytometric analysis was performed by a FACScan (BD Bioscience). Splenic T cells from C57BL/6J mice Gamma-secretase inhibitor were starved in RPMI1640 + 0.1% FBS at 37°C and 5% CO2 for 4 h at the cell concentration of 1 × 106/mL. After the starvation, cells were resuspended in RPMI1640 + 0.1% bovine serum albumin (BSA), and seeded in the plates precoated with anti-CD3/ephrin-Bs

at 2 × 105 cells/well. The plates were centrifuged at 350 rpm for 3 min to achieve rapid contact between the cells and the bottom of the culture wells. The cells were incubated at 37°C and 5% CO2 for 2 h. Then, the cells were harvested and washed with ice-cold PBS. Cell lysis and subsequent Western blotting were performed learn more as previously described [[58]] with minor modifications. Briefly, cells were lysed in cell lysis buffer containing 50 mM Tris-HCl, pH 7.5, 150 mM NaCl, 1% Triton X-100, 1 mM sodium vanadate, 50 mM sodium fluoride, and protease inhibitor cocktail (Sigma Aldrich). For immunoprecipitation, RIPA lysing buffer (50 mM Tris-HCl, pH 7.5, 137 mM NaCl, 2 mM EDTA, 1% NP-40, 0.1% SDS, 0.5% sodium deoxycholate, 1 mM sodium vanadate, 50 mM sodium fluoride, and protease inhibitor cocktail) was used. The lysates were boiled with SDS-loading buffer. Equal amount of sample proteins (35 μg) were separated on 7.5–16% SDS-PAGE and transferred onto PVDF membranes (Immobilon, Millipore, Billerica, MA, USA). The membranes were first incubated with TBST (20 mM Tris-HCl,

Ergoloid pH 7.5, 137 mM NaCl, 0.1% Tween20) containing 5% nonfat dried milk and probed with specific antibodies using primary and horseradish peroxidase-conjugated goat anti-rabbit secondary antibodies (Cell Signaling Technologies, Danvers, MA, USA). Immune complexes were detected by chemiluminescence (Immobillon Western, Millipore). For immunoprecipitation, total cell lysates were incubated with anti-PY antibody (clone 4G10, Millipore) and protein G-sepharose (GE Healthcare Bio-Sciences AB, Sweden) for 18 h at 4°C. The immunoprecipitates were washed with lysis buffer and then with PBS. The blotting membranes were incubated with biotinylated rabbit anti-goat IgG (BA-5000, Vector Laboratories, Burlingame, CA, USA) followed by the amplification with ABC system (Vectastain Elite ABC Reagent, Vector Laboratories).