Cellular and molecular changes and immune response in the intestinal mucosa during Trichinella spiralis early infection in rats

Abstract

Background: The main targets of the host’s immune system in Trichinella spiralis infection are the adult worms (AW), at the gut level, and the migrant or newborn larvae (NBL), at systemic and pulmonary levels. Most of the studies carried out in the gut mucosa have been performed on the Payer’s patches and/or the mesenteric lymph nodes but not on the lamina propria, therefore, knowledge on the gut immune response against T. spiralis remains incomplete. Methods This study aimed at characterizing the early mucosal immune response against T. spiralis, particularly, the events taking place between 1 and 13 dpi. For this purpose, Wistar rats were orally infected with muscle larvae of T. spiralis and the humoral and cellular parameters of the gut immunity were analysed, including the evaluation of the ADCC mechanism exerted by lamina propria cells. Results A marked inflammation and structural alteration of the mucosa was found. The changes involved an increase in goblet cells, eosinophils and mast cells, and B and T lymphocytes, initially displaying a Th1 profile, characterised by the secretion of IFN-γ and IL-12, followed by a polarization towards a Th2 profile, with a marked increase in IgE, IgG1, IL-4, IL-5 and IL-13 levels, which occurred once the infection was established. In addition, the helminthotoxic activity of lamina propria cells demonstrated the role of the intestine as a place of migrant larvae destruction, indicating that not all the NBLs released in the gut will be able to reach the muscles. Conclusions The characterization of the immune response triggered in the gut mucosa during T. spiralis infection showed that not only an effector mechanism is directed toward the AW but also towards the NBL as a cytotoxic activity was observed against NBL exerted by lamina propria cells.

Oral vaccination with recombinant Lactobacillus plantarum encoding Trichinella spiralis inorganic pyrophosphatase elicited a protective immunity in BALB/c mice

“…The cytokines such as IL-4 secreted by Th2 cells can promote the proliferation, differentiation and antibody production of B lymphocyte; it mainly participates in the immune responses and tissue repair process against T . spiralis [ 57 ]. Our results of ADCC assay showed that TsPPase-specific antibodies promoted macrophage adherence and killing to the NBL, and the cytotoxicity was dose-dependent of anti-TsPPase antibodies [ 58 ].…”

The Role of the Intestinal Epithelium in the “Weep and Sweep” Response during Gastro—Intestinal Helminth Infections

“…T. muris localizes in the caecum with its anterior part anchored in “syncytial tunnels” formed from modified epithelial cells [ 41 ], whereas T. spiralis , N. brasiliensis and H. polygyrus reside in the small intestine [ 42 ]. H. polygyrus attaches to the intestine through coiling around the villi on epithelial cells [ 43 ], N. brasiliensis feeds on host villus tissue [ 44 ] and T. spiralis occupies a few epithelial cells creating a multicellular niche [ 45 ]. Despite the different biology and living niches, their impact on the host immune response shows a number of common features (reviewed below).…”

Oral immunization of mice with recombinant Lactobacillus plantarum expressing a Trichinella spiralis galectin induces an immune protection against larval challenge

“…Th2 cells secrete IL-4, which can promote the proliferation and differentiation of B lymphocytes and stimulate the production of IgG1 and IgE. Th2 cells have been found to participate in the immune response against intestinal nematode infection, which is beneficial to the repair or prevention of tissue damage caused by helminths [ 59 ]. IgG is the main immune force against pathogen infection, and it is also one of the main antibodies produced by the second humoral immune response.…”