The equine mononuclear phagocyte system: The relevance of the horse as a model for understanding human innate immunity.
Authors: Karagianni Anna E, Lisowski Zofia M, Hume David A, Scott Pirie R
Journal: Equine veterinary journal
Summary
# Editorial Summary: The Equine Mononuclear Phagocyte System as a Model for Innate Immunity The mononuclear phagocyte system—comprising bone marrow progenitors, circulating monocytes and resident tissue macrophages—serves as a critical component of both innate and acquired immunity, yet our understanding of macrophage function remains largely informed by rodent studies despite significant functional differences between mouse and human cells. Karagianni and colleagues conducted a comprehensive literature review synthesising current knowledge of the equine mononuclear phagocyte system, examining how macrophage phenotype and function vary by anatomical location and comparing equine immune responses with those of rodent and human models. Their analysis reveals important parallels between equine and human innate immunity that small animal models fail to capture, positioning horses as a valuable large animal model for studying macrophage biology and disease processes directly relevant to human medicine. With the recent equine genome update enabling robust comparative transcriptomic analysis, the authors advocate strongly for future gene expression studies in equine macrophages to elucidate regulatory mechanisms applicable to both human and veterinary research. For equine professionals, this work underscores the relevance of studying naturally occurring disease and immune responses in horses, potentially yielding insights into macrophage-mediated inflammation, infection and tissue repair that could inform management strategies for conditions ranging from recurrent airway obstruction to sepsis and wound healing.
Read the full abstract on PubMed
Practical Takeaways
- •The horse serves as a superior large animal model for understanding innate immune dysfunction and inflammatory conditions relevant to human medicine, supporting evidence-based treatment development.
- •Macrophage-mediated responses vary by tissue location and inflammatory state; understanding this variation helps explain why immune responses and disease presentation differ between organ systems in horses.
- •Genomic and transcriptomic research in equine macrophages may reveal therapeutic targets applicable to both equine and human clinical practice, particularly for immune-mediated inflammatory conditions.
Key Findings
- •The equine mononuclear phagocyte system shares structural and functional similarities with human macrophages that distinguish them from rodent models.
- •Macrophage phenotype and function vary significantly depending on tissue location and are regulated by cytokines, lymphokines, and microbial products.
- •Rodent macrophages exhibit many functional differences compared to human counterparts, making large animal models like horses valuable for translational research.
- •Recent updates to the horse genome enable comparative transcriptomic analysis of macrophage gene expression across species, with potential applications for both veterinary and human research.