2.1. Mice

Wild-type and DEREG BALB/c (MMRRC stock no. 32049; ref. [8,10]) mice were purchased from The Jackson Laboratory (Bar Harbor, ME). Mice were housed and bred at the University of Wisconsin-Milwaukee Animal Resource Center in a humidity-controlled environment at 21 °C under a 12-h light-and-dark cycle. Food and acidified water were provided ad libitum. Genotypic analysis was used to confirm the presence or absence of the transgene encoding the diphtheria toxin receptor. Male and female mice between 5 and 8 weeks of age were used in these studies. All procedures were approved by the University of Wisconsin-Milwaukee Animal Care and Use Committee.