IL22Cre mice have a codon optimized Cre Recombinase (iCre), replacing exon 1 of the Il22 (interleukin 22) gene. The presence of iCre abolishes expression of IL-22. IL-22 is a cytokine expressed by immune cells that is required for immune responses to bacterial infections. Homozygous mice are viable and fertile. When these mice are bred with mice containing loxP-flanked sequence, Cre-mediated recombination will result in deletion of the floxed sequences in the Cre-expressing cells of the offspring. When bred to mice containing a cre-inducible fluorophore, mice serve as a fate reporter that marks cells that had initiated the IL-22 program. Under steady state conditions, iCre expression is restricted to group 3 innate lymphoid cells (ILC3) in the gut and &gamma;&delta; T cells in skin or lung. &gamma;&delta; and CD4 T cells expand in the skin when used as a model of psoriasiform inflammation induced by the TLR7 ligand, imiquimod. An expansion of CD4 T cells, which were induced in innate lymphoid follicles in the colon, was evident during Citrobacter rodentium infection. Homozygous IL-22 deficient mice fail to clear the infection and succumb to the infection by day 8.

Removal of this mouse colony is imminent. If live mice are needed for your studies, it is advised that they be ordered immediately. After removal, the mice will be available from a cryorecovery. IL22Cre knock-out/in mice express Cre recombinase in a subset of lymphoid cells including group 3 innate lymphoid cells in the gut and &gamma;&delta; T cells in skin or lung.