Toxoplasma gondii Suppresses Th2-Induced by Trichinella  spiralis Infection and Downregulates Serine Protease Genes  Expression: A Critical Role in Vaccine Development

Enas Fakhry  Abdel Hamed; Nahed El-Sayed  Mostafa; Eman Magdy Fawzy; Mohamed Nabil  Ibrahim; Basma Hamed  Ibrahim; Mona  Radwan; Marwa Ahmed  Salama

doi:10.18502/ijpa.v18i2.13183

Enas Fakhry Abdel Hamed Department of Medical Parasitology, Faculty of Medicine, Zagazig University, Sharkia, Egypt
Nahed El-Sayed Mostafa Department of Medical Parasitology, Faculty of Medicine, Zagazig University, Sharkia, Egypt
Eman Magdy Fawzy Department of Medical Parasitology, Faculty of Medicine, Zagazig University, Sharkia, Egypt
Mohamed Nabil Ibrahim Department of Clinical Laboratories, College of Applied Medical Sciences, Jouf University, Qurrayat, KSA
Basma Hamed Ibrahim Department of Pathology, Faculty of Medicine, Zagazig University, Sharkia, Egypt
Mona Radwan Department of Community and Occupational Medicine, Faculty of medicine, Zagazig University, Sharkia, Egypt
Marwa Ahmed Salama Department of Medical Parasitology, Faculty of Medicine, Zagazig University, Sharkia, Egypt

DOI: https://doi.org/10.18502/ijpa.v18i2.13183

Keywords: Coinfection; Toxoplasma gondii; Trichinella spiralis; Arginase1

Abstract

Background: Toxoplasma gondii coinfection can modify host immune responses and the severity and spread of other parasites. We investigated how T. gondii and Trichinella spiralis infections counter-regulate each other's immune responses.

Methods: The parasite burden, the expression of T. gondii rhoptry kinase ROP18 and T. spiralis putative serine protease (TsSP), the IgG1 and IgG2a responses, besides histopathological and immunohistochemical staining with iNOS and arginase were used to evaluate the dynamics of coinfection.

Results: Through their effects on host immune responsiveness, coinfection with T. gondii modified the virulence of T. spiralis infection. Coinfected animals with high and low doses of T. gondii demonstrated significant reductions in the T. spiralis burden of 75.2% and 68.2%, respectively. TsSP expression was downregulated in both groups by 96.2% and 86.7%, whereasROP18 expression was downregulated by only 6% and10.6%, respectively. In coinfected mice, elevated levels of T. gondii-specific IgG2a antibodies were detected. Th1 induced by T. gondii inhibits the Th2 response to T. spiralis in coinfected animals with high iNOS expression andlow-arginine1 expression.

Conclusion: T. gondii infection induces a shift toward a Th1-type immune response while suppressing a helminth-specific Th2 immune response, paving the way for developing novel vaccines and more efficient control strategies.