Daily exposure to substantial amounts of inhaled air that includes contaminants and pathogens exposes alveolar epithelial cells and bronchial epithelial cells to pollutants. Localized epithelial defence mechanisms exist to ward off damage, but epithelial cells also play an important part in a number of respiratory diseases. Cell culture, animal models, and human lung tissue can all be used to study how these cells behave in health and illness. The significant benefit of being capable of controlling isolated cells using a number of approaches and exposing them to disease-relevant stimuli in controlled environments is provided by cell culture.
Cell culture enables study of a realistic simulation of biological functions with the flexibility to control and better comprehend them. Cell lines help in investigating these mechanisms to some extent, but serious problems with contamination and misidentification mean that research using them is losing credibility. Primary cells are becoming a more and more popular method for obtaining repeatable outcomes that are reflective of the in vivo environment, but they are not without their own difficulties. Particularly for the research of respiratory diseases, primary cells are ideal models. Understanding lung disorders at the cellular level through cell culture enables researchers to identify relevant targets inside pathogenic processes.
Why study cultured respiratory primary cells?
Epithelial cells can be obtained from a variety of sources, such as immortalised or tumour cell lines, primary cells extracted from lung tissue, or differentiated pluripotent stem cells. They are cultured adhering to an immobile surface, frequently made easier by coating with extracellular matrix elements like collagens. Since primary cells have a finite lifespan, immortalised or tumour-derived cell lines are frequently used for their convenience and inexpensive cost. However, the majority of cell lines do not exhibit typical differentiation patterns and only share a small number of characteristics with epithelial cells in situ.
The fact that primary cells have not been changed to encourage proliferation is a definite advantage. Primary airway epithelial cells demonstrate strong differentiation into the cell kinds and profiles that make up the human airway epithelium under the right circumstances. Primary cells also have the benefit of being able to be obtained from certain patient populations. Remarkably, some disease-specific characteristics remain fundamental to epithelial cells and endure in culture, giving patient models for inherited airway disorders like cystic fibrosis as well as for conditions like asthma.
Isolation of Lungs Epithelial Cells
Alveolar or airway epithelial cells are cultured using a variety of culture systems. Although the alveolar epithelial cell cultivation process is similar to ideal cell culture. After being separated from lung tissue, cells can be isolated as primary cells. Cells are traditionally grown on plastic in submerged cultures, but air-liquid interface culture enables differentiation. When compared to three-dimensional organoid culture, the lung-on-a-chip uses microfluidics technology in conjunction with air-liquid interface exposure.
Lately, a number of significant advancements in epithelial cell culture have been made. These seek to improve upon existing models for the research of lung growth and repair, clinical diagnostics, inhalation toxicity, and the therapeutic use of cultivated epithelial cells in regenerative medicine. Additionally, recent significant advancements in the variety of culture systems used include the development of organs-on-chips and organoid cultures.
- Organoids
They are three-dimensional structures made of lung stem cells that are implanted in a matrix and come from adult or embryonic tissue, or from iPSC. To investigate the role of mesenchymal stem cells as niche cells and potential impairment in respiratory diseases, co-cultures with these cells are used. When primary cells are cultivated in a 3D environment, they live longer and behave more like cells in vivo.
- Organ-on-chip
Microfluidics is used in Organ-on-Chiptechnologies, which enable continuous delivery of new nutrients and growth stimulants to cells as well as simultaneous waste disposal under flow conditions similar to those seen in vivo.
- Gene editing
The application of the CRISPR-Cas9 method for the genetic editing of cultures is another advancement. Because of the length of the cultures and the restricted availability of the numerous cells in differentiated cultures, siRNA technology is not well adapted to changing gene expression in air-liquid interface cultures.
Advantages of primary cells
Primary cell research is beneficial for respiratory research since there are a complex variety of cells that interact and influence one another in this biological environment. Studying in vivo processes in disease-specific conditions and comparison with healthy donor cells are made possible by 3D cell culture employing primary cells from a disease-specific donor. The difficulties of primary cells are worth the potential rewards; it saves time on animal studies or clinical trials based on incorrect cell line results owing to repeatable and accurate models.
The Future
Animal experiments are increasingly being replaced with lung epithelial cell cultures. Better modelling of epithelial cell function in situ in cell culture models is now possible thanks to the development of cutting-edge research tools including iPSC, organs-on-chips, and organoids. Today, laboratories can choose the optimal model for the research question at hand using the various cell sources and culture techniques that are readily available.
The hope that regenerative medicine offers for patients with severe lung conditions will be fulfilled by incorporating these encouraging advancements in cell culture methods into individualised regenerative medicine approaches.
