Intraperitoneal Echinococcus multilocularis infection in mice modulates peritoneal CD4+ and CD8+ regulatory T cell...

Area of Science:

• Immunology
• Parasitology
• Cell Biology

Background:

• Echinococcus multilocularis infection leads to impaired host immunity, favoring parasite survival.
• Chronic infection is characterized by an altered peritoneal immune cell profile.

Purpose of the Study:

• To investigate the immune response in the peritoneal cavity during chronic Echinococcus multilocularis infection.
• To characterize the role of T cells and dendritic cells in host immune evasion.

Main Methods:

• Flow cytometry to analyze CD4+ and CD8+ peritoneal T (pT) cells.
• Quantitative PCR to assess cytokine mRNA expression (IL-4, IFN-γ, TGF-β, IL-10, IL-12).
• Analysis of dendritic cell (DC) surface marker expression and co-culture experiments to evaluate T cell proliferation.

Main Results:

• Infected mice showed increased CD4+ and CD8+ pT cells with a Th2-biased response (high IL-4, low IFN-γ).
• Peritoneal dendritic cells (AE-pDCs) exhibited suppressed maturation markers and reduced ability to stimulate T cell proliferation.
• Regulatory T cells (Treg), including CD4+CD25+ and Foxp3+ subpopulations, were identified and shown to inhibit T cell proliferation.

Conclusions:

• Echinococcus multilocularis infection induces a Th2-skewed immune response and functional impairment of peritoneal dendritic cells.
• Regulatory T cells play a significant role in modulating the host immune response, contributing to parasite persistence.