Abstract：
In this paper, we propose a model that connects two standard inflammatory responses to viral infection, namely, elevation of fibrinogen and the lipid drop shower, to the initiation of non-thrombin-generated clot formation. In order to understand the molecular basis for the formation of non-thrombin-generated clots following viral infection, human epithelial and Madin-Darby Canine Kidney (MDCK, epithelial) cells were infected with H1N1, OC43, and adenovirus, and conditioned media was collected, which was later used to treat human umbilical vein endothelial cells and human lung microvascular endothelial cells. After direct infection or after exposure to conditioned media from infected cells, tissue surfaces of both epithelial and endothelial cells, exposed to 8 mg/mL fibrinogen, were observed to initiate fibrillogenesis in the absence of thrombin. No fibers were observed after direct viral exposure of the endothelium or when the epithelium cells were exposed to SARS-CoV-2 isolated spike proteins. Heating the conditioned media to 60 °C had no effect on fibrillogenesis, indicating that the effect was not enzymatic but rather associated with relatively thermally stable inflammatory factors released soon after viral infection. Spontaneous fibrillogenesis had previously been reported and interpreted as being due to the release of the alpha C domains due to strong interactions of the interior of the fibrinogen molecule in contact with hydrophobic material surfaces rather than cleavage of the fibrinopeptides. Contact angle goniometry and immunohistochemistry were used to demonstrate that the lipids produced within the epithelium and released in the conditioned media, probably after the death of infected epithelial cells, formed a hydrophobic residue responsible for fibrillogenesis. Hence, the standard inflammatory response constitutes the ideal conditions for surface-initiated clot formation.
摘要：
在本文中,我们提出了一个模型，将两种标准的炎症反应与病毒感染联系起来，即,纤维蛋白原升高和降脂淋浴，开始非凝血酶生成的凝块形成。为了了解病毒感染后非凝血酶生成凝块形成的分子基础，人类上皮和Madin-Darby犬肾（MDCK，上皮细胞）感染H1N1，OC43和腺病毒，并收集条件培养基，后来用于治疗人脐静脉内皮细胞和人肺微血管内皮细胞。直接感染后或暴露于感染细胞的条件培养基后，上皮细胞和内皮细胞的组织表面，暴露于8毫克/毫升纤维蛋白原，观察到在不存在凝血酶的情况下启动原纤维形成。在直接病毒暴露于内皮或将上皮细胞暴露于SARS-CoV-2分离的刺突蛋白后，未观察到纤维。将条件培养基加热至60°C对原纤维形成没有影响，表明这种作用不是酶促作用，而是与病毒感染后很快释放的相对热稳定的炎症因子有关。自发的原纤维形成先前已被报道并解释为由于与疏水性材料表面接触的纤维蛋白原分子的内部的强相互作用而不是纤维蛋白肽的裂解而导致的αC结构域的释放。接触角测角和免疫组织化学用于证明脂质在上皮内产生并在条件培养基中释放。可能是在感染的上皮细胞死亡之后，形成了负责原纤维形成的疏水残基。因此，标准的炎症反应构成了表面引发的凝块形成的理想条件。
