2.1. Materials and Reagents

The RPMI-1640 medium, Dulbecco’s modified essential medium with high glucose (DMEM) were purchased from HyClone Co. (Logan, UT, USA), while the fetal bovine serum (FBS) was provided by Thermo Fisher Scientific Inc. (Cleveland, OH, USA). Both neutral red and trypan blue were purchased from Amresco Inc. (Los Angeles, CA, USA), and 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl tetrazolium bromide (MTT), concanavalin A (ConA), and lipopolysaccharide (LPS) were provided by Sigma-Aldrich Chemical Co. (St. Louis, MO, USA). The phosphate-buffered saline (PBS) was the product of Solarbio Science and Technology Co. Ltd. (Beijing, China), while the Hanks’ balanced salt solution (HBSS) and the red blood cell lysis buffer were obtained from Beyotime Biotechnology (Beijing, China). The cell counting kit-8 (CCK-8) was the product of Dojindo Laboratories (Kyushu, Japan). Ultrapure water generated from Milli-Q Plus (Millipore Corporation, New York, NY, USA) was used in this study. Other chemicals used in the present work were of analytical grade.

The phycoerythrin (PE)-conjugated anti-mouse CD8a⁺ antibodies and fluorescein isothiocyanate (FITC) anti-mouse CD4⁺ antibodies were bought from Miltenyi Biological Technology Co. Ltd. (Bergisch Gladbach, Cologne, Germany), while the enzyme-linked immunosorbent assay (ELISA) kits [mouse interferon-γ (IFN-γ), interleukin-1β (IL-1β), IL-4, IL-6, and tumor necrosis factor-α (TNF-α)] were bought from Boster Biological Engineering Co. Ltd. (Wuhan, China).