Evolutionary insights into coagulation factor IX Padua and other high-specific-activity variants.

Autor:	Samelson-Jones BJ; Divsion of Hematology, The Children's Hospital of Philadelphia, Philadelphia, PA.; Deparment of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA.; Raymond G. Perelman Center for Cellular and Molecular Therapeutics, Philadelphia, PA; and., Finn JD; Divsion of Hematology, The Children's Hospital of Philadelphia, Philadelphia, PA., Raffini LJ; Divsion of Hematology, The Children's Hospital of Philadelphia, Philadelphia, PA.; Deparment of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA., Merricks EP; Department of Pathology and Laboratory Medicine and.; Blood Research Center, University of North Carolina at Chapel Hill, Chapel Hill, NC., Camire RM; Divsion of Hematology, The Children's Hospital of Philadelphia, Philadelphia, PA.; Deparment of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA.; Raymond G. Perelman Center for Cellular and Molecular Therapeutics, Philadelphia, PA; and., Nichols TC; Department of Pathology and Laboratory Medicine and.; Blood Research Center, University of North Carolina at Chapel Hill, Chapel Hill, NC., Arruda VR; Divsion of Hematology, The Children's Hospital of Philadelphia, Philadelphia, PA.; Deparment of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA.; Raymond G. Perelman Center for Cellular and Molecular Therapeutics, Philadelphia, PA; and.
Jazyk:	angličtina
Zdroj:	Blood advances [Blood Adv] 2021 Mar 09; Vol. 5 (5), pp. 1324-1332.
DOI:	10.1182/bloodadvances.2019000405
Abstrakt:	The high-specific-activity factor IX (FIX) variant Padua (R338L) is the most promising transgene for hemophilia B (HB) gene therapy. Although R338 is strongly conserved in mammalian evolution, amino acid substitutions at this position are underrepresented in HB databases. We therefore undertook a complete 20 amino acid scan and determined the specific activity of human (h) and canine (c) FIX variants with every amino acid substituted at position 338. Notably, we observe that hFIX-R338L is the most active variant and cFIX-R338L is sevenfold higher than wild-type (WT) cFIX. This is consistent with the previous identification of hFIX-R338L as a cause of a rare X-linked thrombophilia risk factor. Moreover, WT hFIX and cFIX are some of the least active variants. We confirmed the increased specific activity relative to FIX-WT in vivo of a new variant, cFIX-R338I, after gene therapy in an HB dog. Last, we screened 232 pediatric subjects with thromboembolic disease without identifying F9 R338 variants. Together these observations suggest a surprising evolutionary pressure to limit FIX activity with WT FIX rather than maximize FIX activity. (© 2021 by The American Society of Hematology.)
Databáze:	MEDLINE
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