WBR0484
| Author | [[PageAuthor::Rim Halaby, M.D. [1]]] |
|---|---|
| Exam Type | ExamType::USMLE Step 1 |
| Main Category | MainCategory::Immunology |
| Sub Category | SubCategory::General Principles |
| Prompt | [[Prompt::The innate immune system is characterized by a wide variety of cell types that act as a primary response to infection. One of the major players in the innate immune system harbors a key protective component known as major basic protein and is induced to proliferate in the presence of IL-5. Which of the following is the most likely function of these cells?]] |
| Answer A | AnswerA::Modulate mast cell reaction |
| Answer A Explanation | AnswerAExp::Eosinophils are important in limiting the extent of the allergic reaction following mast cell degranulation. |
| Answer B | AnswerB::Mediate allergic reaction |
| Answer B Explanation | AnswerBExp::Mast cells and basophils are the important players in mediating allergic reactions. |
| Answer C | AnswerC::Scavenge damaged cells |
| Answer C Explanation | AnswerCExp::Phagocytes such as macrophages and dendritic cells scavenge dead cells and bacterial debris. |
| Answer D | AnswerD::Mediate acute inflammatory response |
| Answer D Explanation | AnswerDExp::The initial mediators of the acute inflammatory response include mainly neutrophils and macrophages. |
| Answer E | AnswerE::Produce antibodies |
| Answer E Explanation | AnswerEExp::Plasma cells are responsible for antibody production. |
| Right Answer | RightAnswer::A |
| Explanation | [[Explanation::Although initially considered a second line of defense only required to protect against parasites, eosinophils have been shown to be quite multifunctional and important modulators of the innate and adaptive immune response. Three major cytokines are key in regulating eosinophil development: IL-3, IL-5, and GM-CSF. Eosinophils also produce several cytotoxic proteins including major basic protein, eosinophil cationic protein, eosinophil peroxidase, and eosinophil-derived neurotoxin that can cause significant tissue dysfunction and damage. MBP is particularly important for the protection against helminth infections and is an important modulator of mast the mast cell reaction often inducing further mast cell degranulation.
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| Approved | Approved::No |
| Keyword | WBRKeyword::Eosinophils, WBRKeyword::IL-5, WBRKeyword::Major basic protein |
| Linked Question | Linked:: |
| Order in Linked Questions | LinkedOrder:: |