Null B2m (B6.129P2-B2mtm1Unc/J; Stock # 002087), Cd14 (B6.129S-cd14tm1Frm/J; Stock # 003726), Il1rn (B6.129S-IL1rntm!Dih/J; Stock # 004754) and Il6 (B6.129S2-IL6tm1kopf/J; Stock # 002650) mice were purchased from Jackson Laboratory (Bar Harbor, Maine). Breeding pairs of Ctss and Ctsf knockout mice were kindly provided by Dr. Chapman (University of California San Francisco). Il1rn and Ctsf null mice were maintained on original mixed C57Bl/6J × 129/SvJ genetic background by heterozygous breeding. Because B2m, Cd14, Il6 and Ctss knockout mice were backcrossed on C57Bl/6J genetic background more than 10 times, these four strains were maintained by homozygous breeding and C57Bl/6J mice from a colony maintained at the University of Texas at Austin (original breeders were purchased from Jackson Laboratories, Bar Harbor, ME) were used as the control or wild-type strain. For Il1rn and Ctsf null mice wild type littermates were used as a control. All of the mutant strains showed normal fertility and there was no evidence of any health problems. To minimize the potential variability from rearing conditions, all breeding colonies were contained in the same room of vivarium. Mice were group-housed four
