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Updated: Jul 19, 2026
Intratracheal Inoculation of Fischer 344 Rats with Francisella tularensis
Published on: September 30, 2017
Early pulmonary response in rats infected with Trichinella spiralis
S M Venturiello1, M L Verzoletti, S N Costantino
1Chair of Immunology, Faculty of Pharmacy and Biochemistry, University of Buenos Aires, Humoral Immunity Studies Institute CONICET, Junín 956, (1113) Buenos Aires, Argentina. sventuri@ffyb.uba.ar
Abstract:
The migratory stage of Trichinella spiralis, the newborn larva, travels along the pulmonary microvascular system on its way to the striated muscle cells. In the present study, an important inflammatory reaction was observed on days 5 and 14 post-infection (p.i.) in the lungs of infected rats. This inflammation was characterized by a Th2 cell phenotype of hyperplastic bronchus-associated lymphoid tissue and by goblet cell hyperplasia. Among the inflammatory cells were eosinophils and mast cells scattered over the pulmonary parenchyma. On day 5 p.i. the number of IgE(+), CD4(+) and CD5(+) cells in the bronchus-associated lymphoid tissue were increased and IgE-secreting lung cells were also detected. At the end of the migratory phase of the infection (day 14 p.i.), only IgE(+) cells were detected in high numbers and in the bronchoalveolar lavage fluid, an increment in the total IgE levels as well as the presence of IgE and IgA anti-larvae surface were also detected. In cytotoxicity assays, cells from the bronchoalveolar lavage had considerable biological activity since they were able to kill the larvae even in the absence of specific antibodies. These results show that the lung is an organ involved in the immune response developed early during a T. spiralis infection and suggest its importance in the protection of the host.
Insights
The lungs mount an early immune response to Trichinella spiralis infection, involving specific cells and antibodies. This study highlights the lung
Area of Science:
- Immunology
- Parasitology
- Pulmonary Medicine
Background:
- Trichinella spiralis newborn larvae migrate through the pulmonary microvasculature.
- Early immune responses in the lungs during parasitic infections are not fully understood.
Purpose of the Study:
- To investigate the pulmonary immune response during the migratory phase of Trichinella spiralis infection in rats.
- To characterize the cellular and molecular changes in the lung post-infection.
Main Methods:
- Histological examination of lung tissue from infected rats at 5 and 14 days post-infection.
- Immunohistochemistry to identify inflammatory cell populations (CD4+, CD5+, IgE+).
- Measurement of IgE levels in bronchoalveolar lavage fluid and assessment of larval killing activity.
Main Results:
- Significant inflammatory reactions observed, including Th2 cell phenotype, lymphoid hyperplasia, and goblet cell hyperplasia.
- Increased numbers of IgE+, CD4+, and CD5+ cells in lung-associated lymphoid tissue by day 5 post-infection.
- Elevated IgE levels and presence of IgE/IgA anti-larvae antibodies in bronchoalveolar lavage fluid by day 14 post-infection.
- Bronchoalveolar lavage cells demonstrated direct larval killing activity.
Conclusions:
- The lung plays a crucial role in the early immune response to Trichinella spiralis infection.
- Pulmonary immune cells and molecules contribute to host defense against migrating larvae.
- The lung's involvement suggests its importance in protective immunity during early-stage parasitic infections.
