Related Experiment Video
Updated: Jun 26, 2026
Three-Dimensional Cell Culture Models to Investigate the Epithelial Barrier in Eosinophilic Esophagitis
Published on: May 10, 2024
Eosinophil-associated matrix remodeling in a sterile granulomatous inflammation model: a temporal histopathological
Bruno Marques Vieira1,2,3, Milla Bezerra Paiva4, Juliane Siqueira Francisco4
1Laboratório de Citocinas, Department. of Immunology, Instituto de Microbiologia Prof. Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil. brunomarquesv@gmail.com.
Abstract:
Eosinophils are increasingly recognized as contributors to tissue remodeling and chronic inflammation, yet their spatiotemporal behavior in sterile granulomatous reactions is incompletely defined. We performed a day 1-14 histopathological time course of a reproducible sterile granuloma induced by implantation of a heat-coagulated egg white pellet into the murine peritoneum. The reaction showed a biphasic inflammatory pattern with early neutrophil predominance followed by a sustained eosinophil-rich phase that persisted through late remodeling. Across time points, lesions progressed from exudative inflammation with prominent fibrin to organized fibroplasia and neovascularization, culminating in collagen-dominated encapsulation by day 14. Eosinophils concentrated at the pellet-tissue interface, frequently displaying apoptosis and degranulation, and occurring in close spatial association with fibroblasts and macrophages. At late time points, the outer granuloma zone contained mononuclear phagocyte/macrophage-like cells alongside dense connective tissue maturation. Together, these findings provide a temporal histopathology atlas of sterile implant granuloma maturation and introduce a semiquantitative framework that summarizes key tissue-composition transitions (fibrinous exudate → fibroplasia/collagen encapsulation) alongside eosinophil enrichment at the pellet-tissue interface.
Insights
This study maps sterile granuloma development over 14 days, revealing eosinophils play a key role in tissue remodeling and inflammation. The findings detail the transition from initial inflammation to collagen encapsulation.
Area of Science:
- Immunology
- Pathology
- Histology
Background:
- Eosinophils are implicated in tissue remodeling and chronic inflammation.
- Their precise role in sterile granulomatous reactions requires further elucidation.
Purpose of the Study:
- To define the spatiotemporal behavior of eosinophils during sterile granuloma formation.
- To create a histopathological timeline of sterile implant granuloma maturation.
Main Methods:
- Induction of sterile granulomas via heat-coagulated egg white pellets in murine peritoneum.
- Histopathological analysis of granuloma development from day 1 to day 14.
- Semiquantitative assessment of tissue composition and cellular infiltration.
Main Results:
- A biphasic inflammatory response was observed: early neutrophils followed by sustained eosinophils.
- Granulomas progressed from exudative inflammation to fibroplasia, neovascularization, and collagen encapsulation.
- Eosinophils localized at the pellet-tissue interface, showing apoptosis and degranulation near fibroblasts and macrophages.
Conclusions:
- This study provides a detailed temporal atlas of sterile implant granuloma maturation.
- Eosinophil enrichment at the interface is a key feature of this process.
- A framework for understanding tissue transitions in granuloma development was established.
