W131 - Piroxicam Induces Colitis in NSGS Mice Humanized with IL10-deficient HSPCs

Rosa Romano – Stanford University; Esmond Lee – Stanford University; Allison Boss – Stanford University; Bing Wang – Stanford University; Neetu Saini – Stanford University; Liwen Xu – Stanford University; Suzette Shipp – Stanford University; Robert Freeborn – Stanford University; Michelle Mantilla – Stanford University; Mara Pavel-Dinu – Stanford University; Matthew Porteus – Stanford University; Rosa Bacchetta – Stanford University; Maria Grazia Roncarolo – Stanford University

Abstract Text: Very early onset inflammatory bowel disease (VEO-IBD) is a life-threatening form of pediatric IBD that affects children younger than 6-years-old. In these genetically susceptible patients, an uncontrollable immune response to antigens of unknown origin results in excessive and chronic intestinal inflammation for which current treatments are often insufficient. The most severe form of VEO-IBD is caused by loss-of-function (LOF) mutations of the IL10, IL10RA, and IL10RB genes which are crucial for immune tolerance through IL-10 signaling. Although Il10-deficient mice provided critical insights in IBD, there is a need for humanized mouse models that allows for testing novel cell and gene therapies as a definitive cure. To meet this clinical need, we created a novel humanized mouse model of IL10 deficiency by engrafting NSGS mice with human CD34+ hematopoietic stem and precursor cells (HSPCs) in which the IL10 gene has been knocked out by a multi-guide CRISPR/Cas9 strategy with high efficiency. Upon successful reconstitution with human immune cells across disease-relevant tissues, we provided the mice with 200 ppm of piroxicam in their diet to trigger intestinal inflammation. After 7-14 days of piroxicam treatment, mice that were reconstituted using IL10-deficient human cells showed an increase in fecal Lipocalin-2 (fLcn-2) compared to mice that were engrafted with HSPCs that were either wildtype or in which a functional copy of IL10 cDNA was inserted. There results illustrate that we were able to induce colitis in IL10-deficient humanized NSGS mice which paves the way for testing novel cell and gene therapies to treat IL10-deficient VEO-IBD.