regulatory T cells – BioQuakes

We’ve all probably heard of pneumonia, or even know someone who has had it. Pneumonia is a lung infection that can be caused by bacteria, viruses, or fungi. This infection causes the lungs’ air sacs to fill with fluid, making it hard to breathe. The majority of cases of community acquired pneumonia are linked to Streptococcus pneumoniae (the pneumococcus). Because there is a significant chance of developing bloodstream infection in these cases, the fatality rate is high. Even with antibiotic treatments and vaccines, the fatality rate is 20% for young adults and 60% for the elderly. Although the reason why some individuals are more susceptible to this disease and why others are not has been a mystery for decades, scientists have discovered a cell that may provide some answers.

At the University of Liverpool, the Bacterial Pathogenesis and Immunity Group has identified a subset of white blood cells in mice known as TNFR2 expressing regulatory T cells (Tregs).

In class, we learned that T cells were involved in the cell-mediated response of adaptive immunity. During the immune response, T-helper cells are activated by interleukin to recognize the antigen and trigger the cell-mediated and humoral responses. T-memory cells are created to confer future immunity while T-killer cells are created to kill infected or cancerous cells. A subset of T-cells called regulatory T cells also regulate the immune system. During pneumonia infection specifically, these cells are involved in bacteraemic pneumonia resistance through maintaining and controlling frontline immune responses during infection in the lungs.

When these cells are not functioning correctly or are missing, there is excessive and uncontrolled inflammation that results in tissue damage. This allows the bacteria to enter the bloodstream through the disrupted lung tissue barrier and cause sepsis, which is the body’s life-threatening response to infection.

Professor Aras Kadioglu, the leader of the Bacterial Pathogenesis and Immunity Group, stated, “This is a significant finding, which opens the door to potential new therapies which may target and modulate these subset of Tregs to prevent and treat severe invasive pneumococcal diseases.”

This article caught my attention because I have never heard of this subset of T cells before. Given how severe pneumonia is, it will be interesting to see how scientists will use this information to create new life-saving treatments.

Researchers at the University of Pennsylvania School of Veterinary Medicine, in February 2017, have discovered a trend in T regulatory cells and plasma cells, that explain why these “antibody-producing plasma cells” can last so long. They used a special microscope that shows “movement and interaction” of cells. They found that regulatory T cells in the bone marrow support plasma cells, which disappear without the T cells. Plasma cells are involved in the immune system, and can either be vital or detrimental. To learn more about plasma cells click here. Scientists hope to use this new knowledge of the interaction between regulatory T cells and plasma cells to either increase the amount of plasma cells to fight off a virus, for example, or to decrease the amount in order to stop it from creating a disease. This research also explains why vaccines can last so long. For example, the chicken pox vaccine is only given twice when the person is very young, but they will be protected against the disease even when they are much older. The regulatory T cells support the plasma cells in the bone marrow which create antibodies that fight off viruses, etc. Another article that explains this discovery can be found here. An article that describes more uses of regulatory T cells in the immune system can be found here.

With this discovery, scientists have more power to control, and have more insight into how plasma cells can be sustained over long periods of time.

Here is an image of an antibody that plasma cells create.

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BioQuakes

AP Biology class blog for discussing current research in Biology

Tag: regulatory T cells

How a Unique Type of T-cell Can Protect Against Pneumonia

T Regulatory Cells Help Maintain Plasma Cells

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