Exploring a pico-well based scRNA-seq method (HIVE) for simplified processing of equine bronchoalveolar lavage cells.
Authors: Fegraeus Kim, Riihimäki Miia, Nordlund Jessica, Akula Srinivas, Wernersson Sara, Raine Amanda
Journal: PloS one
Summary
# Editorial Summary Investigating cellular changes in equine asthma (EA) requires robust methods for analysing bronchoalveolar lavage (BAL) samples, yet traditional approaches often struggle with cell fragility and practical constraints in field settings. Fegraeus and colleagues evaluated the HIVE™ scRNA-seq platform—a pico-well-based single-cell technology—to determine whether it could reliably characterise immune cell populations in BAL samples from horses with EA, comparing results against established cytological findings and prior sequencing studies. The method successfully identified major BAL cell types and confirmed previously documented T cell and macrophage subsets, but revealed notable discrepancies: macrophages were substantially overrepresented whilst T cells and granulocytes appeared underrepresented relative to cytological expectations, and T helper subset definition was less precise than in earlier investigations. Interestingly, when mast cells were pre-purified before sequencing, cell recovery matched anticipated frequencies, suggesting the limitation lies in how intact BAL samples are processed rather than the sequencing platform itself. For practitioners, the HIVE method's gentle workflow and compatibility with clinical and field environments offer genuine practical advantages, yet the current cell-capture bias means results should be interpreted cautiously—particularly regarding granulocyte and mast cell proportions—until refinements address these technical shortcomings.
Read the full abstract on PubMed
Practical Takeaways
- •The HIVE method offers practical advantages for field and clinical settings due to its gentle workflow and compatibility with sensitive cells, making it potentially useful for equine respiratory diagnostics
- •Current HIVE implementation has technical limitations in capturing granulocytes and mast cells in mixed BAL samples; practitioners should be aware these cell populations may be underrepresented in results
- •Further method optimization is needed before widespread clinical adoption for comprehensive BAL cell characterization in equine asthma cases
Key Findings
- •HIVE scRNA-seq method successfully identified major BAL cell types in horses with equine asthma but showed macrophage overrepresentation and T cell underrepresentation compared to cytological expectations
- •The method confirmed previously identified T cell and macrophage subpopulations but T helper subsets were less clearly defined than in prior studies
- •HIVE detected fewer granulocytes and mast cells than expected in whole BAL samples, though purified mast cell populations recovered expected cell numbers
- •Eosinophils were detected and characterized for the first time using this method, though further optimization is needed for accurate cell type representation