Cell culture protocols for HDF and L929 cells

HDF cells (CCD-25SK; American Type Culture Collection, Manassas, VA, USA) were grown in Dulbecco’s modified Eagle’s medium (DMEM) Supplemented with 10% foetal bovine serum (FBS), 2 mM l-glutamine, 100 U/mL penicillin, and 100 mg/mL streptomycin, at 37 °C in a humidified incubator with a 5% CO₂ atmosphere^{45 (link)}. In addition, an established mouse fibroblast cell line (L929, catalogue code CCL-1; American Type Culture Collection) was cultured in minimal essential medium Supplemented with 5% foetal calf serum, 100 U/mL penicillin, 100 μL/mL streptomycin, and 2 mmol/L l-glutamine at 37 °C in a humidified incubator with a 5% CO₂ atmosphere^{46 (link)}.