Why We Should be Thanking Henrietta Lacks Today - The Origin of the Polio Vaccine
Scientific discoveries, ranging from cures, medications, and a better understanding of the human body, have, and will, continue to change the world for the better. The discovery of HeLa cells is one of the greatest and most influential in medicine. HeLa cells were the first immortal cells to be observed in vitro, providing doctors and scientists with insurmountable information. But, before these cells were known to the world as HeLa, they simply belonged to a woman named Henrietta Lacks.
Henrietta Lacks was a poor, black woman from Virginia. She was a fierce woman and had a special place in the hearts of her loved ones. Before the world knew her, she was only known in her small town as a loving mother, wife, and friend. In early 1951, when she fell ill and visited a doctor, she was unfortunately diagnosed with cervical cancer. She was treated at Johns Hopkins Hospital where her surgeon, Dr. Lawrence Wharton Jr., took a tissue sample from Henrietta before he operated. The sample of Henrietta’s tissue was the catalyst for major change within the medical field, when Wharton sent it to Dr. George Gey, the head of the Tissue Culture Laboratory at Johns Hopkins. Gey was determined to create the first immortal cell line, which he thought could expand and revolutionize medical research. Gey was correct. Presently, immortal cell lines are used because they provide an unlimited supply of cells for scientists to experiment on, while remaining cost effective and ethical in practice. Henrietta fought a hard battle with her cervical cancer, but sadly, she passed away in late 1951.
What made HeLa cells different from Gey’s previous failed experiments was that HeLa cells were cancerous, immortal, and had a great multiplicity value. The cancerous aspect of the cells is caused by the human papillomavirus (HPV). When HPV injects its DNA into normal human cells, an inhibitory protein is produced to block a mutation repair protein from doing its job. Because of this, HeLa cells have an abnormal number of chromosomes that can reach a number of almost double the normal 46 chromosomes that human cells have. In regards to the multiplicity rate, one cancerous cell can typically multiply into 5 cancerous cells, but Henrietta Lacks had syphilis which greatly affects the growth of a cancer by increasing the rate. Therefore, there is no finite number of cells that HeLa can multiply into. Moreover, HeLa cells are immortal because of the enzyme telomerase. To protect genes, chromosomes have end caps called telomeres that withstand the normal wear that the chromosomes go through. Gradually in normal cells, the telomeres will deplete enough to stop the cell from dividing. Telomerase is able to rebuild telomeres, thus allowing the cell to live longer. HeLa cells have active telomerases that keep telomeres long and ready to be divided again. All these aspects played a key role in HeLa’s success as the first immortal cell line.
While HeLa cells were being discovered, the Polio epidemic was devastating the United States of America. The polio virus mostly affected children, causing them to suffer from paralysis and potentially death. A scientist, Jonas Salk, was determined to create a vaccine to defend people against the disease, using an idea that was different from his colleagues... He thought of the “inactivated” vaccine: one that contained the three types of polio viruses he discovered earlier in his research. Viruses like polio use host cells to inject their DNA and use the cell like a factory to make more viral particles. Salk took the three types of the polio virus, killed them with formaldehyde, and injected them into patients. He found that though the formaldehyde killed the virus, the viral proteins were not as affected, which meant the body was able to develop immunity. Because HeLa multiplies so quickly, Salk was able to use the cells to mass produce the killed polio virus for vaccines. With mass production of this vaccine, many were saved from the debilitating virus.
We owe a lot to Henrietta Lacks. Without her cells, thousands more could have suffered from polio. Scientists have learned so much from these cells and will continue to use them to learn even more. Though Henrietta is gone, part of her will be here forever. Her influence will continue to be present throughout the scientific community.
References:
Skloot, Rebecca. The Immortal Life of Henrietta Lacks. Broadway Books, 2011.
https://www.immune.org.nz/vaccines/vaccine-development/brief-history-vaccination
https://www.smithsonianmag.com/science-nature/henrietta-lacks-immortal-cells-6421299/
https://www.tebu-bio.com/blog/2017/11/28/hela-cells-the-first-cell-line/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3341241/
https://www.inverse.com/article/31538-henrietta-lacks-immortal-cells-cervical-cancer
https://www.sciencedaily.com/releases/2013/11/131107132825.htm
https://www.scientificamerican.com/article/5-ways-henrietta-lacks-changed-medical-science/
