*2.3. Cell Culture*

Human epithelial type 2 (HEp-2) cell lines were obtained from the American Type Culture Collection (ATCC® CCL23™). The cells were cultured in RPMI-1640 containing 10% foetal bovine serum, 2 mM glutamine, and antibiotics (penicillin G, 60 mg/L; streptomycin, 100 mg/L; amphotericin B, 50 mg/L) under a humid atmosphere (37 ◦C, 5% CO2) for 96 h until confluent. Media were replaced every three days. The cells were washed with phosphate-buffered saline and passaged twice before use, again, once confluent.
