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Updated: May 3, 2026
Trichuris muris Infection: A Model of Type 2 Immunity and Inflammation in the Gut
Published on: May 24, 2011
Giardiasis in mice. I. Prolonged infections in certain mouse strains and hypothymic (nude) mice
I C Roberts-Thomson1, G F Mitchell
1Department of Gastroenterology, Royal Melbourne Hospital, Victoria, Australia.
Abstract:
The natural history of Giardia muris has been studied in inbred mouse strains and hypothymic (nude) mice derived from a specific pathogen-free facility. Although giardiasis was readily established in several mouse strains, marked variation was observed in the time course of spontaneous elimination of the parasite. During a 10-week study, fecal excretion of Giardia cysts remained relatively constant in C3H/He mice, but decreased at a variable rate in other mouse strains. Resistance to reinfection was greater in strains in which the duration of primary infection was relatively short. Hypothymic (nude) mice derived from a strain showing a relatively rapid elimination of Giardia (BALB/c) maintained a stable infection with high cyst counts. Nude mice reconstituted with lymphoid cells from syngeneic thymus-intact mice showed a progressive reduction in cyst excretion and reconstitution with limited numbers of lymphoid cells from thymus-intact mice previously exposed to Giardia accelerated resolution of infection. In nude mice, giardiasis was associated with a reduction in the villus-crypt ratio of jejunal mucosa, but the degree of change was greater in nude mice reconstituted with lymphoid cells. This Giardia model involving inbred strains and nude mice permits further dissection of the function of thymus-derived cells in intestinal immune responses and induction of changes in small bowel morphology.
Insights
This study reveals that thymus-derived cells are crucial for resolving Giardia muris infections in mice. Reconstituting nude mice with these cells accelerated parasite elimination and normalized gut morphology, highlighting their role in intestinal immunity.
Area of Science:
- Immunology
- Parasitology
- Gastroenterology
Background:
- Giardia muris infection, or giardiasis, is a common intestinal parasite affecting various hosts.
- The immune response and host factors influencing Giardia elimination and intestinal changes are not fully understood.
- Inbred mouse strains and immunodeficient models offer valuable tools for studying host-parasite interactions.
Purpose of the Study:
- To investigate the natural history of Giardia muris infection in different inbred mouse strains and hypothymic (nude) mice.
- To elucidate the role of thymus-derived cells in the resolution of giardiasis and associated intestinal alterations.
- To establish a murine model for dissecting intestinal immune responses to Giardia.
Main Methods:
- Studied Giardia muris infection in specific pathogen-free inbred mouse strains and nude mice.
- Monitored fecal cyst excretion over a 10-week period to assess parasite elimination.
- Reconstituted nude mice with lymphoid cells from syngeneic thymus-intact mice (naïve or previously infected) to evaluate immune reconstitution.
- Assessed jejunal mucosal morphology by measuring the villus-crypt ratio.
Main Results:
- Significant variation in spontaneous Giardia elimination was observed among mouse strains.
- C3H/He mice showed sustained fecal cyst excretion, while other strains exhibited variable elimination rates.
- Nude mice maintained persistent infections with high cyst counts, unlike their thymus-intact counterparts.
- Reconstitution of nude mice with lymphoid cells accelerated Giardia elimination, with prior exposure enhancing this effect.
- Giardiasis caused reduced jejunal villus-crypt ratios, more pronounced in reconstituted nude mice.
Conclusions:
- Thymus-derived cells play a critical role in the immune response leading to the resolution of Giardia muris infection.
- The murine model using inbred and nude mice is effective for studying thymus-dependent intestinal immunity and parasite-induced morphological changes.
- Understanding these immune mechanisms can inform strategies for managing giardiasis and related gastrointestinal disorders.
