PMC:2674207 / 2181-3455 JSONTXT

{"project":"sentences","denotations":[{"id":"T20","span":{"begin":0,"end":10},"obj":"Sentence"},{"id":"T21","span":{"begin":11,"end":98},"obj":"Sentence"},{"id":"T22","span":{"begin":99,"end":374},"obj":"Sentence"},{"id":"T23","span":{"begin":375,"end":606},"obj":"Sentence"},{"id":"T24","span":{"begin":607,"end":793},"obj":"Sentence"},{"id":"T25","span":{"begin":794,"end":899},"obj":"Sentence"},{"id":"T26","span":{"begin":900,"end":1032},"obj":"Sentence"},{"id":"T27","span":{"begin":1033,"end":1274},"obj":"Sentence"}],"namespaces":[{"prefix":"_base","uri":"http://pubannotation.org/ontology/tao.owl#"}],"text":"Background\nThe immune system protects the human body from viruses, bacteria, parasites, and fungi. When one of these foreign invaders enters the body, immune system cells called T lymphocytes recognize specific molecules on the invader's surface and release chemical messengers (cytokines) that recruit and activate other types of immune cell, which then attack the invader. Sometimes, however, the immune system responds to a normally harmless material (for example, house-dust mites or grass pollen; scientists call these materials allergens) and triggers an allergic disease such as asthma or hay fever. Contact with an allergen activates a type of T lymphocyte called a T helper-2 (Th2) cell that subsequently makes (expresses) three cytokines called interleukin-4 (IL-4), IL-5, and IL-13. These cytokines ultimately cause inflammation (swelling) of the part of the body exposed to the allergen. Corticosteroids, which suppress the expression of cytokines by Th2 cells, are often used to treat inflammation in allergic diseases. Other treatments for these common conditions—about 50 million people in the US have an allergic disease—include minimizing exposure to allergens and diminishing the response of the immune system to allergens by using various immunotherapies."}