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16 Cards in this Set
- Front
- Back
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What are the two main functions of innate immunity?
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First line of defense against microbes(skin and mucosa) and stimulates the adaptive immune response(phagocytes act as APCs to induce the differentiation of T cells and secrete interleukin 12(IL-12) to induce Th-1 differentiation.
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Which system is able to respond to a broader array of foriegn motifs, innate or adaptive immunity?Why?
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Adaptive immunity. The recombination of antigen receptor genes allows adaptive immunity to recognize 10(7) antigens. Recognition receptors used in innate immunity lack recombination ability.
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Which system is better at discriminating self from nonself, innate or adaptive immunity.
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Innate immunity. Adaptive immunity is responsible for autoimmunity, whereas there is no known autoimmunity associated with the innate immune system.
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How does the innate immune system distinguish between foriegn and self?
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Innate immunity occurs in response to motifs that are characteristics of microbes but not of mammalian cells(Gram neg lipopolysaccharide(LPS), Gram pos. teichoic acid, and viral double stranded RNA).
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Why have microbes not adapted to avoid the motifs recognized by innate immunity?
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Innate immunity targets motifs that are indispensable to the microbe.
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Name the three different epithelial layers of the human body that are considered important aspects of innate immunity.
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Skin, GI tract mucosa, and respiratory epithelium. Realize that the alimentary and respiratory tracts are contiguous with the external environment.
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Name the threeprincipal effector cells of the innate immune system apart from epithelial cells.
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Monocytes/macrophages, neutrophils, and NK cells.
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What endothelial surface structure allows rolling of leukocytes along the endothelial wall adjacent to infection.
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E-selectins weakly bind to carbohydrate ligands on leukocytes resulting in alternating (rolling along the endothelial surface).
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What endothelial surface structure allows for extravasation of leukocytes into the interstitial area of infection?
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Vascular cell adhesion molecule(VCAM) and intercellular adhesion molecule(ICAM) bind strongly to integrins on leukocytes allowing for extravasation.
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Mannose receptors and scavenger receptors are mechanisms to identify and ingest microbes utilized by what type of phagocyte?
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Macrophages
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How do NK cells kill infected cells?
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NK cells identify virus infected cells by failing to identify host major histocompatibility complexe 1(MHC-1). MHC-1 molecules are normally present on the surface of host cells and inhibit NK cell killing, but are down regulated when infected by viruses and other intracellular pathogens.
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How do NK cells kill infectedcells?
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NK cells(and cytotoxic T cells) use perforins(create pores in the cell membrane) and granzymes(induce apoptosis).
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Deficiencies of NK cells presispose to what types of infections?
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Intracellular infections, including intracellular microbes and viruses.
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Of the three effector cells of innate immunity(macrophages, neutrophils, and NK cells), which is least likely to injure host tissue?
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NK cels, which only attack those cells lacking a host MHC-1. On te other hand, macrophages and neutrophils can injure host tissue via nonspecific reactive O2 intermediates.
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Which CD marker is useful for distinguishing NK cells from other immune cells? What is the function of this marker?
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CD16 binds theFc region of immununoglobulin G(IgG).
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Which of the complement pathways is considered part of theadaptive immune system?
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The classical pathway. The alternative pathway is triggered by direct recognition of exterior features of the microbe. The lectin pathway is triggered by mannose binding lectin, which attaches to microbial surfaces containing the mannose sugar. In contrast, the classical pathway relies on IgM, IgG1, or IgG3 to recognize and attach to the microbe and thus is dependent on adaptive immunity.
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