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bioRxiv · 10.1101/2021.03.16.435730

An inconvenient association between granzyme A and Nicotinamide Nucleotide Transhydrogenase

Rawle, D. J.·Le, T.·Dumenil, T.·Bishop, C.·Yan, K.·Nakayama, E.·Bird, P. I.·Suhrbier, A.
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Abstract

Granzyme A (GzmA) is a serine protease secreted by cytotoxic lymphocytes, with GzmA-/- mouse studies informing our understanding of GzmAs physiological function. We show herein that GzmA-/- mice have a mixed C57BL/6J and C57BL/6N 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, rather than loss of GzmA, was responsible for this phenotype by constraining lymphocyte infiltration. A new CRISPR active site mutant C57BL/6J GzmAS211A mouse provided the first insights into GzmAs 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 {approx}27% of Run Accessions and {approx}38% of Bioprojects listing C57BL/6J as the mouse strain, had Nnt sequencing reads inconsistent with a C57BL/6J background. The Nnt issue has clearly complicated our understanding of GzmA and may similarly have influenced studies across a broad range of fields.

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Rawle, D. J., Le, T., Dumenil, T., Bishop, C., Yan, K., Nakayama, E., Bird, P. I., Suhrbier, A.. 2021-03-17. An inconvenient association between granzyme A and Nicotinamide Nucleotide Transhydrogenase. https://doi.org/10.1101/2021.03.16.435730

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