Immune Cell Responses and Cytokine Profile in Intestines of Mice Infected with Trichinella spiralis

Abstract

The intestinal phase is critical for trichinellosis caused by Trichinella spiralis (T. spiralis), as it determines both process and consequences of the disease. Several previous studies have reported that T. spiralis induces the initial predominance of a Th1 response during the intestine stage and a subsequent predominance of a Th2 response during the muscle stage. In the present study, immune cells and cytokine profile were investigated in the intestine of mice infected with T. spiralis. The results showed that the number of eosinophils, goblet cells, mucosal mast cells, and 33D1+ dendritic cells (DCs) increased during the intestinal phase of the infection. Among these, eosinophils, goblet cells, and mucosal mast cells continued to increase until 17 days post infection (dpi), and the number of 33D1+ DCs increased compared to wild type; however, it did not change with the days of infection. The mRNA and protein levels of Th1 cytokines IL-2, IL-12, and IFN-γ and the Th2 cytokines IL-4, IL-5, IL-10, IL-13, and TGF-β were all increased in the tissues of the small intestine in infected mice; however, in general, Th2 cytokines increased more than Th1 cytokines. In conclusion, our findings suggest that T. spiralis infection can induce an increase of small intestine mucosal immune cells and add further evidence to show that the intestinal mucosal immune system of infected mice was induced toward mixed Th1/Th2 phenotypes with the predominance of Th2 response at the early stage of infection.

Primary characterization of the immune response in pigs infected with Trichinella spiralis

“…A subset of T lymphocytes, the CD4+ T cells, plays a key role in parasitic infection and can polarize into Th1, Th2, Treg, and Th17 cells upon antigenic stimulation. T. spiralis and its secretory products can suppress inflammatory responses and induce Th2-type immune responses, as determined by the elevated Th2-associated cytokine levels observed in infected animals [17,18]. The Th1 phenotype immune response is induced during the intestinal stage and predominantly induces a Th2-type immune response during the ML phase [19].…”

Molecular Characterization of Fructose-1,6-bisphosphate Aldolase From Trichinella spiralis and Its Potential in Inducing Immune Protection

“…IL-10 has a dual role in protective immune responses directed against the diverse life stages of T. spiralis parasites. IL-4 plays an important role as a positive regulator of intestinal mast cell responses and is involved in expelling intestinal adult worms in vivo (Ding et al, 2017). On the contrary, IL-10 has a negative effect on protecting newborn larvae, and the lack of IL-10 leads to improved immunity against NBL, as well as decreased numbers of ML cysts, which is associated with elevated IFN-γ (Helmby and Grencis, 2003).…”

Cytokine Profiling Plays a Crucial Role in Activating Immune System to Clear Infectious Pathogens

“…With respect to the Th2 type immune response, in vitro studies have shown that helminth parasite antigens are capable of dendritic cells activating, inducing the synthesis of Th2 cytokines such as IL-4, IL-5, IL-10, and IL-13 [147,149,153,169]. Likewise, studies in in vivo models have shown that helminth parasites infection is a significant increase in the synthesis of IL-4, IL-5, IL-10, and IL-13 [150,151,159,170] (Figure 5). IL-10 may suppress antigen presentation by dendritic cells and inhibition of IL-12 secretion.…”