Abstract
This paper describes a new human alveolar epithelial cell line (hAELVi - human Alveolar Epithelial Lentivirus immortalized) with type I-like characteristics and functional tight junctions, suitable to model the air-blood barrier of the peripheral lung. Primary human alveolar epithelial cells were immortalized by a novel regimen, grown as monolayers on permeable filter supports and characterized morphologically, biochemically and biophysically. hAELVi cells maintain the capacity to form tight intercellular junctions, with high trans-epithelial electrical resistance (> 1000 Ω*cm²). The cells could be kept in culture over several days, up to passage 75, under liquid-liquid as well as air-liquid conditions. Ultrastructural analysis and real time PCR revealed type I-like cell properties, such as the presence of caveolae, expression of caveolin-1, and absence of surfactant protein C. Accounting for the barrier properties, inter-digitations sealed with tight junctions and desmosomes were also observed. Low permeability of the hydrophilic marker sodium fluorescein confirmed the suitability of hAELVi cells for in vitro transport studies across the alveolar epithelium. These results suggest that hAELVi cells reflect the essential features of the air-blood barrier, as needed for an alternative to animal testing to study absorption and toxicity of inhaled drugs, chemicals and nanomaterials.
Highlights
The alveolar epithelium of the peripheral lung is mainly comprised of two cell types, alveolar type I (ATI) and alveolar type II (ATII) cells, both forming the air-blood barrier, which is responsible for gas exchange
No further information on the implemented genes can be provided at this time
To confirm the formation of tight junctions we investigated the expression of characteristic proteins – zona occludens (ZO-1) and occludin in human alveolar epithelial lentivirus immortalized (hAELVi) cells (Fig. 2A,B) grown under liquid-liquid conditions (LLC)
Summary
The alveolar epithelium of the peripheral lung is mainly comprised of two cell types, alveolar type I (ATI) and alveolar type II (ATII) cells, both forming the air-blood barrier, which is responsible for gas exchange. While the cuboidal ATII cells produce lung surfactant proteins to reduce the alveolar surface tension, the squamous ATI cells essentially represent the barrier between blood and air space of the lung; they form a tight epithelium sealed by intercellular connections, i.e., tight junction complexes (Crandall and Matthay, 2001). Isolated human ATI-like cells in primary culture (hAEpC) are to date the best model to reflect the in vivo situation of the airblood barrier due to their ability to form tight junctions and to exhibit high trans-epithelial electrical resistance (TEER). The latter is a widely accepted parameter for tightness of an epithelium and its barrier function.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
