College of Veterinary Medicine, Hunan Provincial Key Laboratory of Protein Engineering in Animal Vaccines, Hunan Collaborative Innovation Center for Safety Production of Livestock and Poultry, Hunan Agricultural University, Changsha, 410128, China.
College of Veterinary Medicine, Hunan Provincial Key Laboratory of Protein Engineering in Animal Vaccines, Hunan Collaborative Innovation Center for Safety Production of Livestock and Poultry, Hunan Agricultural University, Changsha, 410128, China.
Ticks Tick Borne Dis. 2019 Jan;10(1):170-175. doi: 10.1016/j.ttbdis.2018.10.005. Epub 2018 Oct 17.
Ticks and tick-borne diseases are major global health threats. During blood feeding, ticks insert their hypostomes into hosts and inject an array of anticoagulant molecules to maintain fluidity of the blood-meal. These anticoagulant molecules may provide insights into understanding the feeding biology of ticks and to develop vaccines against infestations. In Haemaphysalis flava, the heat shock cognate 70 (HSC70), a member of the heat shock protein (HSP) family, is differentially expressed in salivary glands at different levels of engorgement during blood feeding. However, its function in ticks is largely not known. The present study was designed to explore the possible effects of HSC70 on the plasma. The open reading frame (ORF) of HSC70 was expressed in a prokaryotic system, and recombinant HSC70 (rHSC70) was purified and characterized. The anticoagulation activity of rHSC70 was estimated by measuring prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT) and fibrinogen (FIB) with/without its inhibitor, VER155008. The results demonstrated that rHSC70 from H. flava extended TT (P < 0.001) and FIB clotting times (>300 s), but showed little effect on PT and APTT. Adding an inhibitor reversed anticlotting effects of rHSC70 on TT and FIB. These data indicate that rHSC70 is an anticoagulant agent, and the anticlotting activity likely attributes to the inhibition of thrombin and the transformation of fibrinogen into fibrin.
蜱虫和蜱传疾病是全球主要的健康威胁之一。在吸血过程中，蜱虫将其口下板插入宿主体内，并注入一系列抗凝分子，以保持血液的流动性。这些抗凝分子可以帮助我们了解蜱虫的吸血生物学，并开发针对寄生虫感染的疫苗。在中华革蜱中，热休克同源蛋白 70（HSC70）是热休克蛋白（HSP）家族的一员，在吸血过程中随着饱血程度的不同，在唾液腺中呈现出不同水平的差异表达。然而，它在蜱虫中的功能在很大程度上尚不清楚。本研究旨在探索 HSC70 对血浆可能产生的影响。采用原核表达系统表达 HSC70 的开放阅读框（ORF），并对重组 HSC70（rHSC70）进行纯化和鉴定。通过测量凝血酶原时间（PT）、部分活化凝血酶时间（APTT）、凝血酶时间（TT）和纤维蛋白原（FIB），评估 rHSC70 的抗凝活性，同时加入其抑制剂 VER155008。结果表明，来自中华革蜱的 rHSC70 延长了 TT（P<0.001）和 FIB 凝固时间（>300s），但对 PT 和 APTT 影响较小。加入抑制剂后，rHSC70 对 TT 和 FIB 的抗凝作用被逆转。这些数据表明，rHSC70 是一种抗凝剂，其抗凝活性可能归因于对凝血酶的抑制和纤维蛋白原向纤维蛋白的转化。
