Seahorse analysis
Assays using the Seahorse XF 24 cell metabolism analyzer (XFe24, Seahorse Bioscience, Billerica, MA, USA) were performed following the manufacturer’s instructions. Purified WT and CCR2 KO B cells were pre-stimulated with 10 μg/ml LPS (L2880, Sigma Aldrich, St. Louise, CA, USA) for 1 h and detected in XF medium under basal conditions. Subsequently, 1.5 μM oligomycin (abs42024304, Absin Bioscience, Shanghai, China), 1 μM fluoro-carbonylcyanide phenylhydrazone (FCCP) (C2920, Sigma Aldrich) and 500 nM rotenone (R8875, Sigma Aldrich) plus 1 μM antimycin A (abs42013402, Absin Bioscience) were sequentially added, at the appropriate time of detection. Oxygen consumption rates (OCR) were quantified to reflect the cellular energy metabolism level.