Department of Biochemistry, University of Veterinary Medicine Hannover, Foundation, 30559 Hannover, Germany.
Research Center for Emerging Infections and Zoonoses (RIZ), University of Veterinary Medicine Hannover, Foundation, 30559 Hannover, Germany.
Int J Mol Sci. 2022 Aug 11;23(16):8953. doi: 10.3390/ijms23168953.
(, Gram negative) and (.) (Gram positive) can cause severe diseases in pigs. During infection, neutrophils infiltrate to counteract these pathogens with phagocytosis and/or neutrophil extracellular traps (NETs). NETs consist of a DNA-backbone spiked with antimicrobial components. The NET formation mechanisms in porcine neutrophils as a response to both of the pathogens are not entirely clear. The aim of this study was to investigate whether (serotype 2, C3656/0271/11) and (serotype 2, strain 10) induce NETs by NADPH oxidase- or CD18-dependent mechanisms and to characterize phenotypes of NETs in porcine neutrophils. Therefore, we investigated NET induction in porcine neutrophils in the presence and absence of NET inhibitors and quantified NETs after 3 h. Furthermore, NETosis and phagocytosis were investigated by transmission electron microscopy after 30 min to characterize different phenotypes. and induce NETs that are mainly ROS-dependent. induces NETs that are partially CD18-dependent. Thirty minutes after infection, both of the pathogens induced a vesicular NET formation with only slight differences. Interestingly, some neutrophils showed only NET-marker positive phagolysosomes, but no NET-marker positive vesicles. Other neutrophils showed vesicular NETs and only NET-marker negative phagolysosomes. In conclusion, both of the pathogens induce ROS-dependent NETs. Vesicular NETosis and phagocytosis occur in parallel in porcine neutrophils in response to serotype 2 and serotype 2.
（革兰氏阴性）和（革兰氏阳性）可导致猪的严重疾病。在感染过程中，中性粒细胞通过吞噬作用和/或中性粒细胞胞外陷阱（NETs）来对抗这些病原体。NETs 由带有抗菌成分的 DNA 骨架组成。猪中性粒细胞对这两种病原体的 NET 形成机制尚不完全清楚。本研究旨在研究（血清型 2，C3656/0271/11）和（血清型 2，菌株 10）是否通过 NADPH 氧化酶或 CD18 依赖的机制诱导 NETs，并对猪中性粒细胞中 NET 的表型进行表征。因此，我们在存在和不存在 NET 抑制剂的情况下研究了猪中性粒细胞中 NET 的诱导，并在 3 小时后定量了 NET。此外，通过透射电子显微镜在 30 分钟后研究 NETosis 和吞噬作用，以表征不同的表型。和诱导主要依赖 ROS 的 NETs。诱导部分依赖 CD18 的 NETs。感染 30 分钟后，两种病原体均诱导囊泡状 NET 形成，仅略有差异。有趣的是，一些中性粒细胞仅显示 NET 标志物阳性的吞噬溶酶体，但没有 NET 标志物阳性的囊泡。其他中性粒细胞显示囊泡状 NET 和仅 NET 标志物阴性的吞噬溶酶体。总之，两种病原体均诱导依赖 ROS 的 NET。囊泡状 NETosis 和吞噬作用在猪中性粒细胞中同时发生，以响应血清型 2 和血清型 2。
