Western blot analysis
Proteins from spleen tissues were separated by SDS-PAGE and transferred to PVDF membranes. The membranes were then incubated overnight at 4 °C with antibodies against the protein of interest, including BCL-2 (D17C4; 3498; Cell signaling), Bax (D2E11; 5023; Cell signaling), GAPDH (D16H11; 5174T; Cell signaling) over-night at 4 °C. Protein quantification was measured in optical density units using Image Lab software (Bio-Rad, CA, USA) and was normalized to the corresponding sample expression of GAPDH.