Immortalised cell line

Immortalised cell line refers to a population of cells from a multicellular organism which would not normally proliferate indefinitely but have been transformed in a way that allows them to continue dividing for an extended period of time, potentially indefinitely. This transformation can occur naturally, such as in cases of cancer, or can be induced artificially for research purposes. Immortalised cell lines are a critical tool in biological research, medicine, and biotechnology, enabling scientists to study complex biological processes, develop drugs, and produce vaccines.

Overview

In their natural state, most cells have a limited capacity for replication due to the Hayflick limit, a phenomenon where cells lose the ability to divide after a certain number of divisions. This limit is linked to the shortening of telomeres, protective caps on the ends of chromosomes, which shorten with each cell division. Immortalised cell lines bypass this limit through various mechanisms, such as the activation of the enzyme telomerase, which rebuilds telomeres, allowing cells to maintain their division potential indefinitely.

Methods of Immortalisation

Immortalisation can be achieved through several methods, including:

• Viral Transformation: Infection with certain viruses, such as Epstein-Barr virus (EBV) or human papillomavirus (HPV), can induce immortalisation. These viruses introduce genes that override the cell's normal regulatory mechanisms.
• Genetic Modification: Direct manipulation of a cell's genetic material, such as the introduction of the hTERT gene, which encodes the catalytic subunit of telomerase, can also lead to immortalisation.
• Spontaneous Immortalisation: Rarely, cells can become immortalised spontaneously through mutations that occur during cell culture.

Applications

Immortalised cell lines have numerous applications in scientific research and industry:

• Drug Discovery and Development: They are used for screening potential therapeutic compounds and understanding drug mechanisms.
• Cancer Research: Immortalised cancer cell lines allow for the study of cancer biology, including tumor growth, metastasis, and drug resistance.
• Genetic Studies: These cell lines provide a stable platform for studying gene function and genetic diseases.
• Protein Production: They are used in the production of therapeutic proteins and vaccines.

Ethical Considerations

The use of immortalised cell lines raises several ethical issues, particularly concerning consent and ownership. The case of Henrietta Lacks and the HeLa cell line is a notable example, highlighting the importance of obtaining consent from individuals or their families when using cells for research.

Common Immortalised Cell Lines

Some well-known immortalised cell lines include:

• HeLa: The first immortalised human cell line, derived from cervical cancer cells.
• HEK293: Human embryonic kidney cells, widely used in various fields of research.
• Jurkat: A line of human T lymphocytes, used in immunological research.

Conclusion

Immortalised cell lines are invaluable tools in the life sciences, contributing to our understanding of cellular and molecular biology, aiding in the development of new therapies, and advancing our knowledge of cancer and other diseases. However, their use must be balanced with ethical considerations to ensure respect for the individuals from whom these cells originate.