Comparison of the broncoalveolar lavage fluid proteomics between foals and adult horses.
Authors: Rivolta Alejandra A, Bujold Adina R, Wilmarth Phillip A, Phinney Brett S, Navelski Joseph P, Horohov David W, Sanz Macarena G
Journal: PloS one
Summary
# Editorial Summary Understanding the developmental trajectory of lung immunity in horses requires detailed knowledge of the protective proteins present in the lower respiratory tract, yet until recently the protein composition of bronchoalveolar lavage fluid (BALF) across different ages remained largely uncharacterised. Rivolta and colleagues used advanced mass spectrometry techniques to identify and quantify 704 distinct proteins in BALF samples from seven neonates (under one week old), four foals (5–7 weeks), and six adult horses, comparing their relative abundances across age groups. Neonates exhibited significantly lower concentrations of 332 immune-related proteins compared to both older foals and adults, with notably reduced levels of immunoglobulins, complement cascade components, ferritin, and key macrophage receptors—findings that align with the known clinical susceptibility of young foals to respiratory infections. These proteomic differences suggest that the equine neonatal lung relies on alternative protective mechanisms during the critical early weeks of life, highlighting why neonatal respiratory disease remains a significant clinical challenge and informing potential interventions to support pulmonary immunity in at-risk foals. Practitioners managing neonatal foals should consider this developmental immunological deficit when assessing respiratory health and may find value in strategies designed to enhance or support early lung defences during this vulnerable window.
Read the full abstract on PubMed
Practical Takeaways
- •Neonatal foals have immature pulmonary immune defenses, making them vulnerable to respiratory infections during the first weeks of life—heightened biosecurity and monitoring are critical
- •The identified immune protein deficiencies in neonates suggest that passive transfer of colostral antibodies and early respiratory exposure management are particularly important for protecting newborn foals
- •This baseline proteomic data provides reference values for future studies on neonatal respiratory disease and potential interventions to improve innate immune function in vulnerable foals
Key Findings
- •Neonatal horses have significantly lower relative expression of immune-related proteins in BALF compared to foals and adult horses (FDR < 0.01)
- •704 total proteins identified in BALF with 332 related to immune function across all age groups
- •Neonates showed reduced expression of immunoglobulins, complement cascade proteins, ferritin, and macrophage receptors
- •Differential BALF proteome composition between age groups may explain increased susceptibility to pulmonary infections in neonates