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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.

Trichinellosis is a globally-distributed zoonotic parasitic disease caused by nematode worms of the genus Trichinella. One of the most common species of Trichinella known to affect human health is T. britovi ; however, it is relatively poorly investigated. A thorough knowledge of the proteins expressed by Trichinella is important when developing immunological detection methods and vaccines and studying its interactions with the host. The present study uses the Pichia pastoris expression system to produce a soluble TbCLP antigen which induces strong antibody responses in the host during natural infection. Our results demonstrate the feasibility of TbCLP antigen production in yeasts, which are able to carry out post-translational modifications such as glycosylation and disulfide bond formation; they also indicate that the glycosylated TbCLP antigen had immunogenic effects in the tested mice and induced a mixed Th1/Th2 response, and was associated with a reduced larval burden after challenge with T. britovi. Subsequent in vitro stimulation of mice splenocytes revealed that TbCLP most likely possesses immunomodulatory properties and may play a significant role in the early phase of infection, affecting host immunological responses. [ABSTRACT FROM AUTHOR]

Helminths and their products can suppress the host immune response to escape host defense mechanisms and establish chronic infections. Current studies indicate that macrophages play a key role in the immune response to pathogen invasion. They can be polarized into two distinct phenotypes: M1 and M2. The present paper examines the impact of the adult Hymenolepis diminuta (HD) tapeworm and its excretory/ secretory products (ESP) on THP-1 macrophages. Monocytes were differentiated into macrophages and cultured with a living parasite or its ESP. Our findings indicate that HD and ESP have a considerable impact on human THP-1 macrophages. Macrophages treated with parasite ESP (with or without LPS) demonstrated reduced expression of cytokines (i.e., IL-1α, TNFα, TGFβ, IL-10) and chemokines (i.e., IL-8, MIP-1α, RANTES, and IL-1ra), while s-ICAM and CxCL10 expression rose after ESP stimulation. In addition, inflammatory factor expression rose significantly when macrophages were exposed to living parasites. Regarding induced and repressed pathways, significant differences were found between HD and ESP concerning their influence on the phosphorylation of ERK1/2, STAT2, STAT3, AMPKα1, Akt 1/2/3 S473, Hsp60, and Hck. The superior immunosuppressive properties of ESP compared to HD were demonstrated with lower levels of IL-1β, TNF-α, IL-6, IL-23, and IL-12p70 following stimulation. The presence of HD and its ESP were found to stimulate mixed M1/M2 macrophage phenotypes. Our findings indicate new molecular mechanisms involved in the response of human macrophages to tapeworm infection, this could be a valuable tool in understanding the mechanisms underlying the processes of immune regulation during cestodiasis. [ABSTRACT FROM AUTHOR]