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Do mice genetically selected for resistance to oral tolerance provide selective advantage for Schistosoma mansoni
José Roberto Machado-Silva1, Renata Heisler Neves, Luciana Ormond da Silva
1Cellular Biology and Genetics Department, Institute of Biology, Rio de Janeiro State University, Brazil.
Abstract:
A highly evolved relationship exists between the parasitic flatworm Schistosoma mansoni and its vertebrate hosts that include the use of host immune signals by parasites. The S. mansoni infection was studied in two strains of mice genetically selected, over 18 generations of assortative mating, for extreme phenotypes of susceptibility (TS) and resistance (TR) to immunological tolerance. The objective was to observe whether the different host genetic backgrounds affected the outcome of experimental schistosomiasis. Fecal egg excretion, tissue egg count, worm recovery, and adult worm morphology and morphometry were monitored throughout the period of infection. TR mice presented total fecal egg excretion and thickness of tegument in adult male worms significantly higher than TS mice. Therefore, the comparative analysis of mice with extreme phenotypes of immunological response turns out to be useful in host-parasite relationship studies. Our results suggest that the TR mouse immunological profile provides a more favorable environment for the development of S. mansoni.
Insights
Host genetics significantly impact Schistosoma mansoni infection outcomes. Resistant (TR) mice showed higher egg excretion and thicker worm teguments, suggesting a favorable environment for parasite development in TR hosts.
Area of Science:
- Parasitology
- Immunology
- Genetics
Background:
- The parasitic flatworm Schistosoma mansoni has a complex relationship with its hosts, utilizing host immune signals.
- Understanding host genetic influences on parasitic infections is crucial for disease control.
Purpose of the Study:
- To investigate the effect of host genetic background on experimental Schistosoma mansoni infection.
- To compare infection outcomes in mice with extreme phenotypes of susceptibility (TS) and resistance (TR) to immunological tolerance.
Main Methods:
- Studied S. mansoni infection in two genetically selected mouse strains (TS and TR) over 18 generations.
- Monitored fecal egg excretion, tissue egg count, worm recovery, and adult worm morphology and morphometry.
Main Results:
- TR mice exhibited significantly higher fecal egg excretion compared to TS mice.
- Adult male worms from TR mice showed a significantly thicker tegument.
- These findings indicate distinct host responses influencing parasite development.
Conclusions:
- Comparative analysis of extreme host phenotypes is valuable for host-parasite relationship studies.
- The immunological profile of TR mice appears more conducive to S. mansoni development.
