Lopes Bruno Rafael Pereira, da Silva Gabriel Soares, de Lima Menezes Gabriela, de Oliveira Juliana, Watanabe Aripuanã Sakurada Aranha, Porto Bárbara Nery, da Silva Roosevelt Alves, Toledo Karina Alves
São Paulo State University (UNESP), Institute of Biosciences, Humanities and Exact Sciences, São José do Rio Preto - SP, Brazil.
São Paulo State University (UNESP), School of Sciences, Humanities and Languages, Assis, Brazil.
Int Immunopharmacol. 2022 May;106:108573. doi: 10.1016/j.intimp.2022.108573. Epub 2022 Feb 16.
Human respiratory syncytial virus (hRSV) is an infectious agent in infants and young children which there are no vaccines or drugs for treatment. Neutrophils are recruited for airway, where they are stimulated by hRSV to release large amounts of neutrophil extracellular traps (NETs). NETs are compound by DNA and proteins, including microbicidal enzymes. They constitute a large part of the mucus accumulated in the lung of patients, compromising their breathing capacity. In contrast, NETs can capture/inactivate hRSV, but the molecules responsible for this effect are unknown.
We selected microbicidal NET enzymes (elastase, myeloperoxidase, cathepsin-G, and proteinase-3) to assess their anti-hRSV role.
Through in vitro assays using HEp-2 cells, we observed that elastase, proteinase-3, and cathepsin-G, but not myeloperoxidase, showed virucidal effects even at non-cytotoxic concentrations. Elastase and proteinase-3, but not cathepsin-G, cleaved viral F-protein, which is responsible for viral adhesion and fusion with the target cells. Molecular docking analysis indicated the interaction of these macromolecules in the antigenic regions of F-protein through the active regions of the enzymes.
Serine proteases from NETs interact and inactive hRSV. These results contribute to the understanding the role of NETs in hRSV infection and to designing treatment strategies for the inflammatory process during respiratory infections.
人呼吸道合胞病毒（hRSV）是一种婴幼儿感染病原体，目前尚无疫苗或药物用于治疗。中性粒细胞被募集到气道，在那里它们受到hRSV刺激释放大量中性粒细胞胞外陷阱（NETs）。NETs由DNA和蛋白质组成，包括杀菌酶。它们构成了患者肺部积聚的黏液的很大一部分，损害了他们的呼吸能力。相比之下，NETs可以捕获/灭活hRSV，但负责这种作用的分子尚不清楚。
我们选择杀菌性NET酶（弹性蛋白酶、髓过氧化物酶、组织蛋白酶G和蛋白酶-3）来评估它们的抗hRSV作用。
通过使用HEp-2细胞的体外试验，我们观察到弹性蛋白酶、蛋白酶-3和组织蛋白酶G，而不是髓过氧化物酶，即使在非细胞毒性浓度下也显示出杀病毒作用。弹性蛋白酶和蛋白酶-3，而不是组织蛋白酶G，裂解了病毒F蛋白，该蛋白负责病毒与靶细胞的粘附和融合。分子对接分析表明这些大分子通过酶的活性区域在F蛋白的抗原区域相互作用。
NETs中的丝氨酸蛋白酶相互作用并使hRSV失活。这些结果有助于理解NETs在hRSV感染中的作用，并为呼吸道感染期间炎症过程的治疗策略设计提供帮助。
