Participation of Treg cells in equine Recurrent Airway Obstruction
Authors: Claudio Henriquez, Gabriel Moran, Barbara Perez, Natalia Morales, Hugo Folch
Journal: Frontiers in Immunology
Summary
# Editorial Summary: Regulatory T Cells in Equine Recurrent Airway Obstruction Recurrent airway obstruction represents a significant immune-mediated respiratory disease in horses, yet the regulatory mechanisms controlling its progression remain incompletely understood. Henriquez and colleagues examined T regulatory (Treg) cell populations in blood and bronchoalveolar lavage fluid from susceptible horses before and after exposure to mouldy hay, using flow cytometry to identify cells expressing CD4, CD25, and Foxp3 markers. Horses developing RAO showed marked increases in CD4+Foxp3+ cells in both compartments, whilst CD4+CD25(high) cells accumulated specifically within the airways during active disease rather than in peripheral blood—a critical distinction suggesting localised immune regulation at the site of inflammation. The findings reveal substantial populations of CD4+CD25(high)Foxp3- and CD4+CD25(null)Foxp3+ cells alongside classical Treg phenotypes, indicating heterogeneous regulatory T cell involvement in disease modulation. For practitioners managing RAO cases, this work supports the emerging view that disease resolution involves active regulatory immune mechanisms in the airways rather than simple antigenic avoidance alone, potentially informing future therapeutic strategies targeting these regulatory pathways to enhance natural disease resolution.
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Practical Takeaways
- •RAO involves dysregulation of regulatory T cell populations in the airways; understanding this mechanism may inform future immunomodulatory treatment strategies
- •The distinction between active disease and remission correlates with specific T cell marker profiles in BALF, potentially providing a diagnostic or prognostic biomarker
- •Moldy hay exposure triggers measurable immunological changes in susceptible horses, supporting strict environmental management as a core preventive strategy
Key Findings
- •Percentage of CD4+, Foxp3+ regulatory T cells significantly increased in peripheral blood and bronchoalveolar lavage fluid from horses with RAO compared to controls
- •CD4+, CD25(high) cells were greatly augmented in BALF of RAO-positive horses, with further increases during active disease versus remission
- •Airway accumulation of regulatory T cells in RAO suggests these cells modulate the course of immune-mediated bronchial inflammation and may facilitate resolution