Zhang Rong, Miao Tingting, Qin Min, Zhao Chengsi, Wang Wei, Zhang Chengcheng, Liu Xinjian, Chen Ying, Chen Ailing, Wang Yong
Experimental Teaching Center of Basic Medicine, Nanjing Medical University, Nanjing, China.
Department of Pathogen Biology, Key Laboratory of Pathogen Biology of Jiangsu Province, Nanjing Medical University, Nanjing, China.
Front Cell Infect Microbiol. 2021 May 4;11:672720. doi: 10.3389/fcimb.2021.672720. eCollection 2021.
(), is a food-borne zoonotic parasite that can cause central nervous system (CNS) injury characterized by eosinophilic meningitis. However, the pathogenesis of angiostrongylosis remains elusive. Natural killer cells (NK cells) are unique innate lymphocytes important in early defense against pathogens. The aim of this study was to investigate the role of NK cells in infection and to elucidate the key factors that recruit NK cells into the CNS.
Mouse model of infection was established by intragastric administration of third-stage larvae. The expression of cytokines and chemokines at gene and protein levels was analyzed by qRT-PCR and ELISA. Distribution of NK cells was observed by immunohistochemistry and flow cytometry. NK cell-mediated cytotoxicity against YAC-1 cells was detected by LDH release assay. The ability of NK cells to secrete cytokines was determined by intracellular flow cytometry and ELISA. Depletion and adoptive transfer of NK cells was induced by tail vein injection of anti-asialo GM1 rabbit serum and purified splenic NK cells, respectively. CXCL1 neutralization experiment was performed by intraperitoneal injection of anti-CXCL1 rat IgG.
The infiltration of NK cells in the CNS of -infected mice was observed from 14 dpi and reached the peak on 18 and 22 dpi. Compared with uninfected splenic NK cells, the CNS-infiltrated NK cells of infected mice showed enhanced cytotoxicity and increased IFN-γ and TNF-α production ability. Depletion of NK cells alleviated brain injury, whereas adoptive transfer of NK cells exacerbated brain damage in -infected mice. The expression of CXCL1 in the brain tissue and its receptor CXCR1 on the CNS-infiltrated NK cells were both elevated after infection. CXCL1 neutralization reduced the percentage and absolute number of the CNS-infiltrated NK cells and relieved brain damage caused by infection.
Our results demonstrate that the up-regulated CXCL1 in the brain tissue recruits NK cells into the CNS and aggravates brain damage caused by infection. The findings improve the understanding of the pathogenesis of angiostrongyliasis and expand the therapeutic intervention in CNS disease.
[某种寄生虫名称]是一种食源性人畜共患寄生虫，可导致以嗜酸性粒细胞性脑膜炎为特征的中枢神经系统（CNS）损伤。然而，管圆线虫病的发病机制仍不清楚。自然杀伤细胞（NK细胞）是独特的先天性淋巴细胞，在早期抵御病原体方面很重要。本研究的目的是探讨NK细胞在[寄生虫名称]感染中的作用，并阐明将NK细胞招募到中枢神经系统的关键因素。
通过胃内给予第三期幼虫建立[寄生虫名称]感染的小鼠模型。通过qRT-PCR和ELISA分析细胞因子和趋化因子在基因和蛋白水平的表达。通过免疫组织化学和流式细胞术观察NK细胞的分布。通过乳酸脱氢酶释放试验检测NK细胞对YAC-1细胞的细胞毒性。通过细胞内流式细胞术和ELISA测定NK细胞分泌细胞因子的能力。分别通过尾静脉注射抗去唾液酸GM1兔血清和纯化的脾NK细胞诱导NK细胞的耗竭和过继转移。通过腹腔注射抗CXCL1大鼠IgG进行CXCL1中和实验。
在感染后14天观察到[寄生虫名称]感染小鼠中枢神经系统中NK细胞的浸润，并在18和22天达到峰值。与未感染的脾NK细胞相比，感染小鼠中枢神经系统浸润的NK细胞表现出增强的细胞毒性以及增加的IFN-γ和TNF-α产生能力。NK细胞的耗竭减轻了脑损伤，而NK细胞的过继转移加剧了[寄生虫名称]感染小鼠的脑损伤。感染后，脑组织中CXCL1的表达及其在中枢神经系统浸润NK细胞上的受体CXCR1均升高。CXCL1中和降低了中枢神经系统浸润NK细胞的百分比和绝对数量，并减轻了[寄生虫名称]感染引起的脑损伤。
我们的结果表明，脑组织中上调的CXCL1将NK细胞招募到中枢神经系统，并加重[寄生虫名称]感染引起的脑损伤。这些发现增进了对管圆线虫病发病机制的理解，并扩展了中枢神经系统疾病的治疗干预措施。
