- Immortalized cell lines have become indispensable tools in modern biology, biotechnology, and medicine because they can proliferate indefinitely under suitable laboratory conditions. Their ability to bypass the normal limits of cellular senescence offers a consistent, reproducible, and readily available source of cells, enabling researchers to perform experiments without the variability and ethical limitations associated with primary cells. These cell lines are widely applied across multiple disciplines, from fundamental research into cellular mechanisms to large-scale industrial production of therapeutic molecules.
- One of the most prominent applications is in basic biological and biomedical research. Immortalized cell lines allow scientists to explore fundamental aspects of cell physiology, gene expression, signal transduction, and metabolic regulation in a controlled environment. Because they are genetically stable over many passages, they serve as standard model systems, allowing results to be compared and reproduced between laboratories worldwide. For example, HeLa cells have been used to study cell cycle regulation, cancer biology, and the molecular basis of viral infections.
- In drug discovery and pharmacological testing, immortalized cell lines are essential for high-throughput screening of chemical compounds. Pharmaceutical companies routinely use them to identify molecules with therapeutic potential, evaluate cytotoxicity, and study mechanisms of drug resistance. The reproducibility of immortalized lines ensures that experimental outcomes are consistent, reducing confounding factors that arise from genetic heterogeneity. Additionally, these cell lines can be genetically engineered to express disease-related genes, making them valuable disease models for preclinical testing.
- In toxicology and safety assessment, immortalized cells are employed as in vitro models to evaluate the safety of chemicals, cosmetics, and environmental pollutants. This approach reduces reliance on animal testing while still providing insights into potential human health hazards. Regulatory agencies often accept data from well-characterized immortalized cell lines as part of safety dossiers for new products, particularly when used in validated testing protocols such as skin irritation assays or genotoxicity screens.
- Immortalized cell lines also have significant roles in virology and vaccine production. Their ability to support the replication of many viruses makes them ideal hosts for viral research and for manufacturing vaccines. For instance, Vero cells are extensively used in the production of vaccines against polio, rabies, and COVID-19. They provide a safe and efficient platform for generating large quantities of viral particles under controlled conditions, meeting the stringent quality requirements of pharmaceutical manufacturing.
- In biopharmaceutical production, immortalized mammalian cell lines such as Chinese hamster ovary (CHO) cells are workhorses for the large-scale synthesis of therapeutic proteins, including monoclonal antibodies, hormones, and clotting factors. CHO cells’ adaptability to suspension cultures in bioreactors and their ability to perform complex post-translational modifications make them ideal for producing proteins with human-compatible glycosylation patterns.
- In addition, immortalized cell lines are central to cancer research. Since many immortalized lines originate from tumors or have been transformed to acquire cancer-like properties, they are used to study tumorigenesis, metastasis, and the cellular response to anticancer agents. They provide insights into oncogene function, tumor suppressor gene loss, and the interaction between cancer cells and their microenvironment.
- Finally, immortalized cell lines are valuable in genetic engineering and biotechnology innovations. They can serve as platforms for CRISPR-Cas9 genome editing, recombinant protein expression, synthetic biology constructs, and personalized medicine applications. In regenerative medicine, although immortalized lines themselves may not always be suitable for transplantation, they are used for testing stem cell differentiation protocols, optimizing culture conditions, and producing feeder layers for stem cell maintenance.
| Table: Representative Immortalized Cell Lines and Their Applications in Research and Industry | |||
| Cell Line | Species / Origin | Key Applications | Notable Examples of Use |
| HeLa | Human cervical cancer | Basic research, cancer biology, virology, drug screening | Polio vaccine development; studies of HPV and HIV; cell cycle regulation |
| CHO (Chinese Hamster Ovary) | Cricetulus griseus (hamster ovary) | Biopharmaceutical production, protein expression, glycosylation studies | Production of monoclonal antibodies, erythropoietin, and clotting factors |
| Vero | African green monkey kidney | Vaccine production, virology, virus-host interaction studies | Production of rabies, polio, and COVID-19 vaccines |
| 293 / HEK293 | Human embryonic kidney | Recombinant protein expression, gene function studies, transfection experiments | Adenoviral vector production, GPCR signaling studies |
| NIH 3T3 | Mouse embryonic fibroblast | Oncogene research, cell transformation assays, fibroblast biology | Ras oncogene studies, growth factor signaling |
| Jurkat | Human T lymphocyte (leukemia) | Immunology, T-cell signaling, apoptosis studies | HIV infection models, immune signaling pathways |
| MCF-7 | Human breast cancer | Cancer biology, hormone response studies, drug testing | Estrogen receptor research, chemotherapeutic drug screening |
| A549 | Human lung carcinoma | Respiratory disease research, drug testing, virology | Influenza and SARS-CoV-2 infection studies |
| U2OS | Human osteosarcoma | Cell cycle, DNA damage response, cancer biology | p53 pathway studies, chromatin remodeling |
| BHK-21 | Baby hamster kidney | Virology, recombinant protein expression, vaccine production | Foot-and-mouth disease vaccine production |
