Novartis Institute for Biomedical Research, CH-4056, Basel, Switzerland.
Developmental and Molecular Immunology, Department of Biomedicine, University of Basel, Basel, Switzerland.
Immunol Lett. 2018 Jun;198:60-65. doi: 10.1016/j.imlet.2018.04.008. Epub 2018 Apr 27.
Dipeptidyl peptidase 9 (DPP9) is a ubiquitously expressed intracellular prolyl peptidase implicated in immunoregulation. However, its physiological relevance in the immune system remains largely unknown. We investigated the role of DPP9 enzyme in immune system by characterizing DPP9 knock-in mice expressing a catalytically inactive S729A mutant of DPP9 enzyme (DPP9 mice). DPP9 mice show reduced number of lymphoid and myeloid cells in fetal liver and postnatal blood but their hematopoietic cells are fully functional and able to reconstitute lymphoid and myeloid lineages even in competitive mixed chimeras. These studies demonstrate that inactivation of DPP9 enzymatic activity does not lead to any perturbations in mouse hematopoiesis.
二肽基肽酶 9（DPP9）是一种广泛表达的细胞内脯氨酰肽酶，参与免疫调节。然而，其在免疫系统中的生理相关性在很大程度上尚不清楚。我们通过对表达 DPP9 酶催化失活 S729A 突变体的 DPP9 敲入小鼠（DPP9 小鼠）进行特征描述，研究了 DPP9 酶在免疫系统中的作用。DPP9 小鼠在胎肝和出生后血液中的淋巴样和髓样细胞数量减少，但它们的造血细胞功能完全正常，甚至在竞争性混合嵌合体中也能够重建淋巴样和髓样谱系。这些研究表明，DPP9 酶活性的失活不会导致小鼠造血发生任何紊乱。
