Cell line and culture maintenance
The Chinese Hamster Ovary (CHO) cell line expressing human monoclonal
anti-Interleukin-1β IgG1 (Kennard et al., 2009) ChK2 437.89.34 was
provided by Pfizer (St. Louis, MO). The cell line was maintained in
shake tubes (Corning or Nalgene) in a humidified incubator (Kuhner
shaker, Basel, Switzerland) at 37˚C, 5% CO2 and 225
rpm. The cells were passaged every 3 days and grown in chemically
defined CD CHO medium (Gibco-Invitrogen, Grand Island, NY), supplemented
with 100 µg/mL hygromycin B (Gibco), 4.5 µg/mL bleocin (Calbiochem, La
Jolla, CA) and 4 mM glutamine (Gibco).