Immunological aspects of human schistosomiasis

Area of Science:

• Immunology
• Parasitology
• Tropical Medicine

Background:

• Helminth infections typically induce T-helper 2 (Th2)-dependent immune responses, characterized by IgE production and eosinophilia.
• The impact of these Th2 responses varies significantly across different host species.
• In murine schistosomiasis, Th1 responses confer protection, while Th2 responses exacerbate egg-induced morbidity.

Purpose of the Study:

• To investigate the differential roles of Th1 and Th2 immune responses in human schistosomiasis.
• To explore the protective mechanisms associated with specific immune responses against helminth reinfection and morbidity.

Main Methods:

• Comparative analysis of immune responses (Th1 vs. Th2) in human and murine schistosomiasis.
• Assessment of IgE antibody production against adult worm and egg antigens.
• Correlation of immune profiles with protection against reinfection and severity of egg-associated morbidity.

Main Results:

• In human schistosomiasis, Th2 responses targeting adult worm antigens correlate with protection against reinfection post-chemotherapy.
• Humans with predominant Th2 responses to egg antigens exhibit reduced egg-associated morbidity compared to those with Th1 responses.
• Contrasting findings with murine models highlight species-specific immune adaptations.

Conclusions:

• Th2-mediated immune responses appear selectively advantageous for human hosts in managing schistosomiasis.
• This understanding has implications for developing effective helminth vaccines and optimizing chemotherapy strategies.
• Further research is needed to explore these host-specific responses in other helminth infections and co-infections.