Bach2

Total proteins were extracted from CD4⁺ T cells using RIPA lysis buffer (Beyotime, Shanghai, China) and quantified with the BCA kit (Beyotime). Equal volume of proteins were subjected to SDS/PAGE and transferred on to PVDF membrane. After blocking in PBS with 5% non-fat milk and 0.05% Tween-20 for 1 h at room temperature, the membrane was incubated overnight at 4°C with corresponding primary antibody of Bach2 (1:500; Abcam), followed by incubation for 2 h with secondary antibodies conjugated with horseradish peroxidase at room temperature. The ECL kit was used to detect immunoreactive bands according to the manufacturer’s instructions (Thermo Scientific, Waltham, MA, U.S.A.).

Total cell lysates (60 μg) and nuclear lysates (5 μg), prepared as described42 (link) or by nuclear extraction kit (Panomics, USA), respectively, were subjected to SDS-PAGE and immunoblotting using primary antibodies against PRDM151 (link), actin (1: 5,000 dilution; Sigma), BACH2 (1: 1,000 dilution; abcam), BCL6 (1: 1,000 dilution; Cell Signaling and 1: 1,000; BioLengend), FOXP1 (1: 1,000 dilution; abcam), PAX5 (1: 500 dilution; Santa Cruz), XBP-1 (1: 500 dilution; Santa Cruz), p65 (1: 500 dilution, Santa Cruz), lamin B (1: 400 dilution; Santa Cruz) and GFP (1: 1,000 dilution; Santa Cruz). The detailed procedures, secondary antibodies used and detection of immunoreactive proteins were as described42 (link).