Characterization of Commercially Available Human Primary Alveolar Epithelial Cells

Area of Science:

• Pulmonary cell biology
• In vitro modeling
• Cellular characterization

Background:

• Existing cell lines like A549 and NCI-H441 have limitations in mimicking in vivo alveolar epithelial cells.
• Commercially available human primary alveolar epithelial cells (hPAEpCs) lack comprehensive characterization.
• Need for well-defined in vitro models for lung research.

Purpose of the Study:

• To comprehensively characterize commercially available hPAEpCs.
• To define optimized culture conditions for hPAEpCs.
• To evaluate hPAEpCs as a model for in vitro lung research.

Main Methods:

• Morphological analysis using electron microscopy.
• Surface marker expression profiling.
• Transcriptomic analysis (bulk and single-cell).
• Functional assays including transepithelial ion transport and permeability.
• Optimization of seeding density and gas-liquid interface culture.

Main Results:

• Optimized hPAEpCs formed tight monolayers with functional ion transport.
• Electron microscopy confirmed alveolar type II cell characteristics (lamellar bodies, microvilli).
• Alveolar type I and II cell markers were detected, but NKX2-1 was absent transcriptomically.
• Cells showed transdifferentiation with passaging (SFTPC-, KRT8high, KRT5-) without affecting permeability.
• UMAP analysis showed minimal cluster shifts despite transcriptomic changes.

Conclusions:

• Commercially available hPAEpCs, under optimized conditions, provide a valuable in vitro model.
• These cells exhibit key alveolar epithelial characteristics and functional properties.
• hPAEpCs are suitable for studies on drug delivery, barrier function, and ion transport.