Toxocara canis mucins among other excretory-secretory antigens induce in vitro secretion of cytokines by mouse splenocytes.

Ewa Długosz,Maciej Klockiewicz,Marcin Wiśniewski,Katarzyna Wasyl

doi:10.1007/s00436-015-4561-5

Abstract

The effect of Toxocara larval antigens on cytokine secretion by mouse splenocytes was studied in vitro. Recombinant mucins were produced in Pichia pastoris yeast, and Toxocara excretory-secretory (TES) antigens were collected from in vitro culture of L2 larvae. Tc-MUC-2, Tc-MUC-3, Tc-MUC-4, and Tc-MUC-5 were expressed as glycoproteins and were specifically recognized by Toxocara canis-infected dog serum antibodies. Mouse splenocytes stimulated with recombinant mucins produced IL-5, IL-6, and TGF-β. Cell stimulation with whole TES products was more effective and resulted in secretion of IL-4, IL-5, IL-6, IL-10, and TGF-β and downregulation of TNF-α production. IFN-γ and IL-17 secretion was noted only after ConA treatment. Cells originating from infected animals produced significantly smaller amounts of these two cytokines compared to control cells, which suggests that Th1 and Th17 response in infected mice is strongly inhibited. However, splenocyte stimulation with both TES and ConA upregulated the production of IFN-γ and IL-17. This shows that TES antigens have strong immunomodulatory properties and are able to induce a broad range of effects on murine immune cells.

Highlights

Toxocara canis is a common nematode parasite of dogs
The presence of glycan moieties on recombinant mucins was confirmed by lectin-binding assay which showed that concanavalin A (ConA) binds to all four glycoproteins
Recombinant mucins were recognized by anti-HIStag (Fig. 1c) and serum antibodies of T. canis-infected dogs (Fig. 1d)

Summary

Introduction

Toxocara canis is a common nematode parasite of dogs. Embryonated eggs are infective to a wide range of mammal hosts. Human toxocariasis is a zoonotic disease prevalent worldwide (Despommier 2003). Larvae migrate through tissues for months up to several years evading the immune attack of the host. They reach several organs such as the lung, liver, eye, and brain causing severe complications. Toxocara worms contribute to the development of allergic diseases, including asthma (Pinelli et al 2008)

Objectives

Methods

Results

Conclusion