Expression analysis of WT or Card14E138A ears 5 days and 1 month after injecton of tamoxifen

The inducible nature of our knock-in mouse strain allowed us to determine the immediate effects of dysregulated CARD14 signalling and compare them to the long term effects of its expression. CARD14E138A-induced skin inflammation and systemic disease were independent of adaptive immune cells, substantially reduced by antibody blocking of TNF and induced by CARD14E138A signaling only in keratinocytes. Overall design: To investigate how psoriasis-associated mutations in CARD14 induce psoriasis, we have generated a Card14LSL-E138A knock-in mouse that allows conditional expression of Card14E138A from the endogenous mouse Card14 locus via tamoxifen activation of CreERT2. The highly penetrant CARD14E138A psoriasis-associated mutation was first identified in a child suffering from GPP and induces CARD14 to constitutively activate NF-kB. The new Card14LSL-E138A strain allowed the immediate and chronic effects of CARD14E138A signaling to be studied, as well as the cell types involved.