PT  - JOURNAL ARTICLE
AU  - Jennifer L. Aron
AU  - Timothy Thauland
AU  - Humza Khan
AU  - Manish J. Butte
TI  - Humanized mice bearing CRISPR/Cas9 Disruption of Signal Transducer and Activator of Transcription 1 (STAT1) to Model Primary Immunodeficiency
AID  - 10.1101/2022.06.20.496920
DP  - 2022 Jan 01
TA  - bioRxiv
PG  - 2022.06.20.496920
4099  - http://biorxiv.org/content/early/2022/06/21/2022.06.20.496920.short
4100  - http://biorxiv.org/content/early/2022/06/21/2022.06.20.496920.full
AB  - Background The search for a single, pathogenic genetic variant in a patient suspected to have a monogenic inborn error of immunity (IEI) often reveals a multitude of rare variants of unknown significance (VUS). Distinguishing which VUS is disease-causing versus the irrelevant, rare variants from the genetic background is slow and difficult. Advances in gene editing technology, particularly CRISPR/Cas9, promise to accelerate the timeline for the development of single-variant animal models, thus affording an experimental system for validating new genes and their variants.Objective We sought to demonstrate a proof-of-concept of using CRISPR/Cas9 in human hematopoietic stem cells (hHSC) to develop of humanized mice bearing a hematopoietic deficiency in signal transducer and activator 1 (STAT1).Methods Using CRISPR/Cas9, we introduced indels into the STAT1 gene of hHSCs and implanted them into immunodeficient mice. The reconstituted immune systems were assessed by flow cytometry.Results Mice transplanted with cells edited to eliminate STAT1 developed human immune systems with diverse cell phenotypes. Lymphocytes from these reconstituted mice showed low expression of STAT1 protein and diminished phosphorylation of STAT1 in response to interferon stimulation. These data mirror the impaired, but not abolished, response to interferons seen in human partial STAT1 deficiency. CRISPR/Cas9 genome editing techniques can be used to rapidly and inexpensively create functional, humanized models of primary immune deficiencies.Competing Interest StatementThe authors have declared no competing interest.