# Mice humanized by syntenic replacement with full-length NLRP3 disease-associated variants model the clinical cryopyrinopathy continuum

## TL;DR

Scientists created mice with human NLRP3 gene variants to study a group of inflammatory diseases called cryopyrinopathies, showing that these mice accurately reflect the human disease spectrum.

## Contribution

The study introduces a novel mouse model with full-length human NLRP3 disease variants, capturing the clinical severity continuum of cryopyrinopathies.

## Key findings

- Five mouse lines with human NLRP3 alleles or CAPS mutations were generated and phenotyped.
- The humanized mice recapitulate the full spectrum of CAPS disease severity observed in humans.
- The results suggest that species-specific regulation or intramolecular epistasis may influence disease modeling.

## Abstract

Next-generation sequencing technologies are increasingly used to diagnose genetic disorders, particularly immunological diseases with broad and overlapping immune dysregulation. Cryopyrin-associated periodic syndromes (CAPS) are caused by gain-of-function mutations in NLRP3 and include 3 autoinflammatory diseases spanning a continuum of severity: familial cold autoinflammatory syndrome (FCAS), Muckle-Wells syndrome (MWS), and neonatal-onset multisystem inflammatory disease (NOMID). Linking NLRP3 variants to protein dysfunction and clinical phenotype remains challenging because of genetic modifiers and environmental factors. We report the generation and phenotyping of 5 mouse lines expressing either the common human NLRP3 allele or 1 of 4 CAPS mutations spanning the disease spectrum from FCAS to NOMID. In these lines, the murine Nlrp3 locus is replaced by syntenic integration of the human NLRP3 locus, yielding 1 line with the common allele and 4 lines each carrying a distinct CAPS mutation. Unlike models in which a human mutation is introduced into the mouse protein, these lines recapitulate the spectrum of disease severity observed in humans. These findings support a model in which evaluation of nonsynonymous mutations in mice is optimized when introduced in the context of the human gene. This suggests that species-specific regulation and/or intramolecular epistasis may impact modeling of disease-associated variants.

Humanization of the entire Nlrp3 locus, including regulatory regions, with human disease-associated variants yields mouse models that mirror the human spectrum of cryopyrin-associated periodic syndromes.