Department of Parasitology, Medical College of Zhengzhou University, Zhengzhou, China.
Biology, School of Life Scence, Zhengzhou University, Zhengzhou, China.
PLoS Negl Trop Dis. 2022 May 2;16(5):e0010395. doi: 10.1371/journal.pntd.0010395. eCollection 2022 May.
A range of helminth species involve the migration of developing larvae through the lung and establish chronic infections in the host that include potent immune regulatory effects. Trichinella spiralis is one of the most successful parasitic symbiotes. After released by intestinal female adult worms, newborn larvae of T. spiralis travel through the circulatory system to the lung and finally reach skeletal muscle cells. As unique inflammation modulator of intracellular parasitism, T. spiralis shows improved responses to autoimmune disease and viral pulmonary inflammation by exerting immunomodulatory effects on innate and adaptive immune cells.
METHODOLOGY/PRINCIPAL FINDINGS: C57BL/6 mice were divided into four groups: uninfected; helminth- T. spiralis infected; P. aeruginosa infected; and co-infected. Mice infected with T. spiralis were incubated for 6 weeks, followed by P. aeruginosa intranasal inoculation. Bronchial alveolar lavage fluid, blood and lung samples were analyzed. We found that T. spiralis induced Th2 response in the mouse lung tissue, increased lung CD4+ T cells, GATA3, IL-4, IL-5 and IL-13 expression. Pre-existing T. spiralis infection decreased lung neutrophil recruitment, inflammatory mediator IL-1β and IL-6 expression and chemokine CXCL1 and CXCL2 release during P. aeruginosa- pneumonia. Furthermore, T. spiralis co-infected mice exhibited significantly more eosinophils at 6 hours following P. aeruginosa infection, ameliorated pulmonary inflammation and improved survival in P. aeruginosa pneumonia.
These findings indicate that a prior infection with T. spiralis ameliorates experimental pulmonary inflammation and improves survival in P. aeruginosa pneumonia through a Th2-type response with eosinophils.
多种蠕虫物种涉及幼虫在肺部的迁移，并在宿主中建立慢性感染，包括强大的免疫调节作用。旋毛虫是最成功的寄生共生体之一。新生的旋毛虫幼虫在肠道雌成虫释放后，通过血液循环系统到达肺部，最终到达骨骼肌细胞。作为细胞内寄生虫的独特炎症调节剂，旋毛虫通过对固有和适应性免疫细胞发挥免疫调节作用，显示出对自身免疫性疾病和病毒性肺部炎症的改善反应。
方法/主要发现：将 C57BL/6 小鼠分为四组：未感染；感染旋毛虫；感染铜绿假单胞菌；和混合感染。感染旋毛虫的小鼠孵育 6 周，然后进行铜绿假单胞菌鼻内接种。分析支气管肺泡灌洗液、血液和肺样本。我们发现旋毛虫在小鼠肺组织中诱导 Th2 反应，增加肺 CD4+T 细胞、GATA3、IL-4、IL-5 和 IL-13 的表达。预先存在的旋毛虫感染可减少铜绿假单胞菌肺炎时肺中性粒细胞募集、炎症介质 IL-1β 和 IL-6 表达以及趋化因子 CXCL1 和 CXCL2 的释放。此外，旋毛虫混合感染的小鼠在铜绿假单胞菌感染后 6 小时表现出更多的嗜酸性粒细胞，改善了铜绿假单胞菌肺炎的肺部炎症并提高了存活率。
这些发现表明，先前感染旋毛虫通过 Th2 型反应和嗜酸性粒细胞改善了铜绿假单胞菌肺炎的实验性肺部炎症并提高了存活率。
