PATHOLOGY MCQ
IMMUNE RESPONSE
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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“eat” microorganisms that have been tagged with antibodies.
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tag pathogenic microorganisms with antibodies
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attack virus-infected cells by releasing chemicals that lead to cell death.
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are phagocytes that attack and kill pathogenic microorganisms.
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Detailed explanation-1: -Natural cytotoxicity receptors directly induce apoptosis (cell death) after binding to Fas ligand that directly indicate infection of a cell. The MHC-independent receptors (described above) use an alternate pathway to induce apoptosis in infected cells.
Detailed explanation-2: -NK cells can kill virally infected of transformed cells via the directed release of lytic granules or by inducing death receptor-mediated apoptosis via the expression of Fas ligand or TRAIL.
Detailed explanation-3: -Once the decision is made to kill, the NK cell releases cytotoxic granules containing perforin and granzymes, which leads to lysis of the target cell.
Detailed explanation-4: -NK cells have multiple mechanisms to kill virus-infected cells, including the engagement of extracellular death receptors and exocytosis of cytolytic granules [4].
Detailed explanation-5: -Natural killer cells recognize and attach to infected cells or cancer cells, then release enzymes and other substances that damage the outer membranes of these cells. Natural killer cells are important in the initial defense against viral infections.