OBJECTIVE LIFE SCIENCE
SIGNALLING IMMUNOLOGY CANCER
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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What is the mechanism of a type I hypersensitivity?
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Ag induces cross-linking of IgE bound to mast cells and basophils with release of vasoactive dilators
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Ab directed against cell surface antigens mediates cell destruction via complement activation or Ab-dependent cell-mediated cytotoxicity (ADCC). RBCs are common targets
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Ag-Ab complexes deposited in various tissues induce complement activation an dan ensuing inflammatory response mediated by massive infiltration of neutrophils
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sensitized T cells (TH1, TH2, and others) release cytokines that activate macrophages or TC cells, which mediate direct cellular damage
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Explanation:
Detailed explanation-1: -Type I (Immediate) Hypersensitivity This form of hypersensitivity involves the activation of basophils and mast cells that release histamine and other inflammatory mediators that drive the clinical features of the response.
Detailed explanation-2: -In type I hypersensitivity, B cells are stimulated (by CD4+ Th2 cells) to produce IgE antibodies specific to an antigen. The difference between a normal infectious immune response and a type 1 hypersensitivity response is that in type 1 hypersensitivity, the antibody is IgE instead of IgA, IgG, or IgM.
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