| First Author | Rawle DJ | Year | 2022 |
| Journal | Elife | Volume | 11 |
| PubMed ID | 35119362 | Mgi Jnum | J:321166 |
| Mgi Id | MGI:6870358 | Doi | 10.7554/eLife.70207 |
| Citation | Rawle DJ, et al. (2022) Widespread discrepancy in Nnt genotypes and genetic backgrounds complicates granzyme A and other knockout mouse studies. Elife 11:e70207 |
| abstractText | Granzyme A (GZMA) is a serine protease secreted by cytotoxic lymphocytes, with Gzma(-/-) mouse studies having informed our understanding of GZMA's physiological function. We show herein that Gzma(-/-) mice have a mixed C57BL/6J and C57BL/6N genetic background and retain the full-length nicotinamide nucleotide transhydrogenase (Nnt) gene, whereas Nnt is truncated in C57BL/6J mice. Chikungunya viral arthritis was substantially ameliorated in Gzma(-/-) mice; however, the presence of Nnt and the C57BL/6N background, rather than loss of GZMA expression, was responsible for this phenotype. A new CRISPR active site mutant C57BL/6J Gzma(S211A) mouse provided the first insights into GZMA's bioactivity free of background issues, with circulating proteolytically active GZMA promoting immune-stimulating and pro-inflammatory signatures. Remarkably, k-mer mining of the Sequence Read Archive illustrated that approximately 27% of Run Accessions and approximately 38% of BioProjects listing C57BL/6J as the mouse strain had Nnt sequencing reads inconsistent with a C57BL/6J genetic background. Nnt and C57BL/6N background issues have clearly complicated our understanding of GZMA and may similarly have influenced studies across a broad range of fields. |
