The HeLa cell line is one of the most important tools in medical science. It was the first “immortal” line of human cells, a population of cells that can reproduce indefinitely in a laboratory setting. This quality allowed for unprecedented scientific study, making the cell line a fixture in labs worldwide. The story behind these cells involves significant scientific advancement intertwined with a complex personal history.
The Origin of the First Immortal Human Cells
The story begins in 1951 with Henrietta Lacks, an African American woman being treated for cervical cancer at Johns Hopkins Hospital. During her treatment, a surgeon collected a sample of her cancerous tumor without her knowledge or permission, a common practice at the time. The tissue was given to Dr. George Otto Gey, head of the Tissue Culture Laboratory at Johns Hopkins, who had been trying for years to grow human cells outside the body.
Previous attempts to culture human cells had always failed, with the cells dying within a few days. Lacks’s cells, however, were different, not only surviving but thriving and doubling in number every 24 hours. They named the cell line “HeLa,” using the first two letters of Henrietta Lacks’s first and last names.
While her cells achieved a form of immortality in the lab, Henrietta Lacks succumbed to her cancer in October 1951, never knowing the scientific legacy she had left behind. Dr. Gey, recognizing the potential of this discovery, began freely sharing the HeLa cells with researchers around the world. This set the stage for decades of medical innovation.
Unique Biological Properties of HeLa Cells
The longevity and utility of HeLa cells stem from unique biological characteristics. Their “immortality” is a direct result of an active version of an enzyme called telomerase. In most normal cells, the protective caps on chromosomes, known as telomeres, shorten with each cell division, leading to cell death. HeLa cells use telomerase to continuously rebuild these telomeres, allowing them to bypass this limit and divide indefinitely.
This immortality is coupled with a rapid and robust growth rate. This prolific nature made them ideal for mass-producing cultures needed for widespread scientific experiments. The aggressive growth that made the cells so valuable in research also made them a notorious laboratory contaminant, capable of infiltrating and taking over other cell cultures.
The properties of HeLa cells are largely attributed to the virus that caused Henrietta Lacks’s cancer: human papillomavirus 18 (HPV18). The virus integrated its genetic material into the cells, disrupting normal cell cycle controls. This resulted in cells with an abnormal number of chromosomes—typically 76 to 80 instead of 46—which contributed to their uncontrolled division.
Scientific and Medical Contributions
The HeLa cell line has touched nearly every field of biomedical research. One of the earliest breakthroughs came in the 1950s during the fight against polio. Scientists discovered that HeLa cells were highly effective for growing large quantities of the poliovirus, which was necessary for developing and testing the polio vaccine created by Jonas Salk.
HeLa cells have been central to cancer research. They helped scientists understand that certain viruses, like HPV, can cause cancer, a discovery that earned a Nobel Prize and led to the HPV vaccine. They have also been used to study how radiation affects cells, test cancer drugs, and investigate leukemia. Over 110,000 research publications are based on studies involving these cells.
The applications extend far beyond cancer and polio. In virology, HeLa cells have been used to study viruses such as HIV, measles, and Ebola. They were important for mapping the human genome and have been used in research on gene regulation and cloning. HeLa cells were even sent on early space missions to test the effects of zero gravity on human cells.
The Ethical Controversy and Legacy
The scientific value of HeLa cells is shadowed by the ethical controversy of their origin. The cells were taken from Henrietta Lacks without her knowledge or consent, a practice that, while common in the 1950s, is now viewed as a violation of patient rights. For more than two decades, the Lacks family was unaware of their matriarch’s immortal cells. They learned the truth in the 1970s when researchers sought them out for blood samples to better understand the cells’ genetics.
The family’s discovery ignited a debate over informed consent, privacy, and equity in research. The situation was complicated in 2013 when the full HeLa genome was sequenced and published online without the family’s permission. This act exposed sensitive genetic information about Henrietta and her living descendants, raising privacy concerns. The publication brought the ethical issues to the forefront of public and scientific discourse.
In response, the National Institutes of Health (NIH) reached an agreement with the Lacks family in 2013. This agreement established a committee, including two Lacks family members, to review applications from researchers seeking to use HeLa genomic data. While this agreement does not cover all uses of the cells, it gives the family a voice in how their genetic legacy is managed. The story of Henrietta Lacks is a foundational case study in bioethics, influencing regulations like the Common Rule, which mandates informed consent.