What are T-cells and their role in the immune system?
So what exactly is your immune system, and what does it do? This is something I know that some of my peers and I have been wondering in biology as we just grazed past the topic. Your immune system is made up of a multitude of cells, organs, and proteins that communicate within the human body to ward off infections and other possible harms to the body’s cells. Specifically, your immune system works to fight cancer cells.
A way that your immune system is unique in fighting possible harm is by storing information. The memory of your immune system is so thorough that even if you are exposed to a disease at a young age, your body stores that information for a time down the road when you might be exposed to the same pathogen once again. One great example of the marvels of the immune system is chicken pox. Often, after children over the age of six months contract and recover from chicken pox, they are considered immune and don’t contract the virus again. This is all thanks to the memory of immune system cells. Once you’ve had chicken pox, the cells within your immune system know to create certain antibodies that help fend off the same infection for a second time. Although you have fought off chicken pox, varicella-zoster virus, the virus that causes it, can remain dormant within your nerve tissue and can lead to a rash known as shingles.
As pathogens like varicella-zoster virus or cancerous cells are sensed by your immune system, white blood cells within it, like macrophages and lymphocytes, release cytokines which are peptides that are used in cell signaling. When released, these cytokines tell the immune system to do its job. This results in affected growth of blood cells as well as cells involved in the immune system and inflammation responses. This allows for cells to activate programmed cell death, also known as apoptosis within cancer cells or increase the life of healthy, normal cells.
An example of lymphocytes that are involved in this process are T lymphocytes, more commonly referred to as T cells. T cells are lymphocytes that originate from the stem cells in your bone marrow. Their main purpose is to eliminate infected or cancerous cells.
One way T cells help you stave off diseases or cancer is by stimulating B cells to produce antibodies in order to bind to pathogens and neutralize them. These antibodies fully engulf the pathogens in order to neutralize them. Some B cells that are stimulated are also memory cells that help the immune system store information about particular antigens so that if they reappear, the immune system can quickly get rid of them.
Another way that T cells can help prevent disease is by directly killing pathogens themselves. These cells are known as cytotoxic T cells meaning they directly kill their target cells. They do so by programming those target cells to undergo apoptosis, or programmed cell death. This prevents the further spread of an infection or the growth of a cancerous tumor.
Bibliography:
Janeway CA Jr, Travers P, Walport M, et al. "Immunobiology: The Immune System in Health and Disease" 5th Edition. www.ncbi.nlm.nih.gov/books/NBK27101/ .
Maurie Markman “B-Cells vs. T-Cells: What Are Helper, Killer and Cytotoxic T Cells.” Cancer Treatment
Centers of America, 12 July 2022, www.cancercenter.com/what-are-b-cells-vs
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