(640) The Cystic Fibrosis Mouse Model Resource Center

Background: The CF mouse model resource center generates, characterizes and distributes mouse models to the CF research community. We make new mouse models in response to CF research community demand. We maintain and distribute CF mouse strains, tissues and cells. We assist researchers in testing therapeutic strategies for CF. We provide essential infrastructure for the CF research community to develop and translate new therapeutic approaches, including somatic gene-editing and other therapies directed at modulator-resistant alleles.

Methods: We maintain and distribute many longstanding CF genetic mouse models and cells, including both conditional and revertible Cftr mutants.

Results: With CRISPR/Cas gene editing, we made and validated a new series of footprint-free disease alleles (F508del, G542X, G551D and W1282X) in the mouse Cftr gene in the C57Bl/6J inbred background. These mice better recapitulate the genetic behavior of these mutations than do the legacy alleles. In order to better model the pharmacology of CFTR in mice, we maintain and distribute mice with a 250 kb complementing wild type human CFTR transgene (Gawenis et al. Sci Rep. 2019;9:11828). We introduced CF-disease mutations into this human CFTR array (F508del, G542X, G551D, W1282X and 3849+10kb C >T). Because the human CFTR gene is present in a multiple-copy array, it is not an ideal substrate for gene editing approaches which use double-stranded DNA breaks. Therefore, we developed mice in which segments of the mouse Cftr gene are replaced with the cognate human exon and short flanks from the introns. Mice homozygous for wild type human exon 11 or wild type human exon 12 replacing cognate sequences in the mouse Cftr gene have wild type phenotypes. We have generated and validated mice with CF-disease mutant human exon replacements (F508del, G542X and R553X). These mice replicate the expected genetics and are sequence-exact models for gene editing therapeutics. We currently are extending the exon-replacement approach to additional exons (wild type and E60X-mutant exon 3, wild type and W1282X-mutant exon 23, and wild type and Q1411X-mutant exon 26).

Conclusions: We will report on current progress on these and other strains of mice of interest to the CF research community.

Acknowledgements: Supported by CFF grant HODGES19R1

References: