Trichinella spiralis is a foodborne zoonotic nematode, which causes trichinellosis. During the infection, parasite evades the host immune responses by direct and indirect (through excretory-secretory products) contact with host immune cells. One of the main targets for immunomodulation induced by helminths are macrophages. In this study, we examined whether direct contact of different stages of T. spiralis can affect the polarization of human THP-1 macrophages. Co-culture of adult parasite stage and cells in direct contact without LPS addition had a significant impact on TNFα levels. Interestingly, in settings with the addition of LPS, the levels of IL-1β and TNFα significantly increased in adult parasite and newborn larvae (NBL) but not for muscle larvae (ML). While we tested muscle larvae ESP products to compare its effect with whole ML parasite, we detect an increase of pro-inflammatory cytokines like IL-1β and TNFα in no LPS conditions. Whereas, muscle larvae ESP significantly suppressed the inflammatory response measured by IL-1β, TNFα, and IL-6 levels and anti-inflammatory IL-10 compared to LPS control. Our findings indicate the anti-inflammatory potential of T. spiralis muscle larvae excretory-secretory products and propose signaling pathways which might be engaged in the mechanism of how muscle larvae ESP affect human macrophages.

旋毛虫是一种食源性人畜共患线虫，可引起旋毛虫病。在感染过程中，寄生虫通过直接和间接（通过排泄-分泌产物）与宿主免疫细胞的接触来逃避宿主的免疫反应。蠕虫诱导的免疫调节的主要目标之一是巨噬细胞。在这项研究中，我们研究了螺旋藻不同阶段是否直接接触会影响人类THP-1巨噬细胞的极化。成年寄生虫阶段和不加LPS的直接接触细胞的共培养对TNFα水平有重大影响。有趣的是，在添加了LPS的环境中，成年寄生虫和新生幼虫（NBL）的IL-1β和TNFα含量显着增加，而肌肉幼虫（ML）则没有。虽然我们测试了肌肉幼虫ESP产品以将其与整个ML寄生虫进行比较，但在没有LPS的情况下，我们检测到促炎性细胞因子（如IL-1β和TNFα）的增加。相比于LPS对照，肌肉幼虫ESP可显着抑制通过IL-1β，TNFα和IL-6水平以及抗炎性IL-10测得的炎症反应。我们的发现表明螺旋螺旋体的抗炎潜力 肌肉幼虫的分泌分泌产物，并提出信号通路，可能参与了肌肉幼虫ESP如何影响人类巨噬细胞的机制。