An immortalized cell line refers to a population of cells that can proliferate indefinitely in vitro, meaning under controlled laboratory conditions. These cells have undergone a transformation that allows them to bypass the normal cellular aging process, known as senescence, and avoid cell death after a finite number of cell divisions.
There are several ways to immortalize a cell line, including:
- Viral transformation: Infection with specific viruses, such as the Epstein-Barr virus (EBV) or the human papillomavirus (HPV), can lead to cellular transformation and immortalization.
- Introduction of specific genes: Transfecting cells with genes that promote cellular proliferation, such as the T-antigen of the SV40 virus, the human telomerase reverse transcriptase (hTERT), or oncogenes, can induce immortalization.
- Spontaneous immortalization: In rare cases, cells can become immortalized spontaneously, often after a large number of passages in culture. This process usually involves genetic mutations that allow the cells to escape senescence.
Immortalized cell lines are widely used in biological and biomedical research due to their ability to divide indefinitely, making them a valuable and renewable resource. They are often employed to study various cellular processes, gene expression, drug metabolism, and the effects of drugs or toxins on cells. However, it’s important to note that immortalized cell lines may have altered cellular characteristics compared to their original tissue source, so results should be interpreted with caution and, if possible, confirmed in primary cells or in vivo models.
