Genotype-Associated Arginase 1 Expression in Rat Peritoneal Macrophages Induced by Toxoplasma gondii
Qian Zhang1, Liuyuan He1, Lanting Kong1
1Department of Parasitology, Provincial Laboratory of Microbiology and Parasitology and the Key Laboratory of Zoonoses Anhui, Anhui Medical University, Hefei, 230032, Anhui, P. R. China.
Abstract:
Toxoplasma gondii induces polarization of mouse macrophages, including both classically activated macrophages (M1) and alternatively activated macrophages (M2) in a genotype-related manner. Here we present a novel result that the Wh6 strain with type Chinese 1, which is predominantly prevalent in China, induces Arg1 expression in a STAT6-dependent manner in primary rat peritoneal macrophages as compared to the PRU stain with type II, which elicited a high expression of Arg1 in a C/EBPβ-dependent manner. In addition, dexamethasone inhibited Arg1 expression in rat macrophages in both treatments. Our data suggest that Arg1 expression, which is abundant in polarized M2 cells, is associated with strain/genotype differences from different pathways.
Insights
Toxoplasma gondii strains differentially regulate arginase 1 (Arg1) expression in rat macrophages. The Chinese Wh6 strain activates Arg1 via STAT6, while the PRU strain uses C/EBPβ, highlighting strain-specific immune responses.
Area of Science:
- Immunology
- Parasitology
- Cell Biology
Background:
- Toxoplasma gondii infection triggers macrophage polarization into M1 and M2 subtypes.
- Macrophage activation pathways are crucial for controlling parasitic infections.
- Strain-specific differences in T. gondii virulence are well-documented.
Purpose of the Study:
- To investigate the molecular mechanisms underlying arginase 1 (Arg1) expression in rat macrophages upon infection with different T. gondii strains.
- To compare the pathways involved in Arg1 induction by Chinese type 1 (Wh6) and European type II (PRU) T. gondii strains.
- To assess the effect of dexamethasone on Arg1 expression in T. gondii-infected macrophages.
Main Methods:
- Primary rat peritoneal macrophages were infected with T. gondii Wh6 (type Chinese 1) and PRU (type II) strains.
- Arginase 1 (Arg1) expression levels were measured.
- STAT6 and C/EBPβ signaling pathways were investigated.
- The impact of dexamethasone treatment was evaluated.
Main Results:
- The Wh6 strain induced Arg1 expression in a STAT6-dependent manner.
- The PRU strain induced Arg1 expression in a C/EBPβ-dependent manner.
- Dexamethasone inhibited Arg1 expression in macrophages infected with both strains.
Conclusions:
- Arginase 1 (Arg1) expression in macrophages is regulated by distinct pathways depending on the infecting T. gondii strain.
- These findings reveal strain/genotype-specific differences in macrophage polarization mechanisms.
- Understanding these pathways is critical for developing targeted therapeutic strategies against toxoplasmosis.
