Soru
NK-natural killer identifies the abnormalities on cells by detecting the amount of what? a. MHC I molecules b. Non-self -molecules c. PAMP-pathogen -associated molecular patterns d. PRR-pattern recognition receptors
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4.7
(190 Oylar)
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Elit · 8 yıl öğretmeni
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Cevap
The correct answer is a. MHC I molecules.Natural killer (NK) cells are a type of cytotoxic lymphocyte that play a crucial role in the innate immune system. They are responsible for identifying and eliminating abnormal cells, such as virus-infected cells or tumor cells, in the body.NK cells recognize and target cells that have downregulated or lost their major histocompatibility complex (MHC) class I molecules on their surface. MHC class I molecules are responsible for presenting peptide fragments derived from intracellular proteins to the immune system. When a cell becomes infected with a virus or undergoes transformation into a tumor cell, it often reduces the expression of MHC class I molecules on its surface. NK cells detect this loss of MHC class I molecules and recognize the cell as abnormal or "selfish," leading to its destruction.Therefore, NK cells identify abnormalities on cells by detecting the amount of MHC class I molecules present on their surface.