Microbiology

Hypersensitivity reactions, by definition, lead to tissue damage. Can they also be beneficial? Explain.

The textbook Microbiology, A Hyman Perspective explains, “allergy is a damaging immune response to a totally harmless environmental antigen generally mediated by IgE also known as hypersensitivity (Nester, 2012).” The immune system (humoral and cellular) can be beneficial and damaging to the host. Like the textbook explains, “the immune response is indeed a two edged sword with a delicate balance between protective immunity and harmful hypersensitivity (Nester, 2012).” Many people are led to believe that hypersensitivities are just harmful for the human body. However, just like the immune system, hypersensitivity can be harmful but it can also be beneficial. These types of hypersensitive are called delayed-type hypersensitivity reactions. These kinds of hypersensitivity reactions are “due to antigen- specific t- cell responses and can occur almost anywhere in the body (Nester, 2012).” A very important lymphocyte that plays an important part in delayed- type hypersensitivity are Effector cytotoxic T cells. According to the textbook, Microbiology: A Human Perspective, “Effector cytotoxix T cells are particularly important because they destroy the infected host cells but it also damages the tissue (Nester, 2012).” For example, an infection with “tubercle bacilli will lead to formation of tissue damaging granulomas that at the same time wall of the invading bacilli and prevent them from spreading (Chegg).” Another example in which delayed- type hypersensitivity in infectious diseases is when “an abscess causes a lot of tissue damage, but at the same time gets rid of the bacteria causing the problem (Chegg).”

A microbiologist argued that there is no such thing as “normal” microbiota in the human body, since the population is dynamic and is constantly changing, depending on diet and external environment. What would be an...