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62 Cards in this Set
- Front
- Back
Discuss the role NK-κβ plays in the host's immune defenses.
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Nuclear transcription factor produced in most cells. Regulates genes for apoptosis, viral replication, inflammation, and autoimmune diseases.
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Explain the reason for identifying the skin as the 1st line of defense and describe its importance in eliminating foreign invaders.
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physical barrier; also "acid mantle" of the skin, acid pH of sweat and sebaceous glands that protects the skin (pH = 4.5-5.5)
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Distinguish the difference between the enzyme lysozyme and the proteoliytic enzymes of the GI tract.
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lysozyme breaks down cell walls of bacteria (it is a carbohydrase), while enzymes of the GI tract are proteolytic
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Define phagocytosis and examine the role of PMNs and monocytes/macrophages.
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macrophages ingest cells only when they are opsonized (coated with with C3b and antibodies)
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List six soluble plasma proteins that participate in host defenses and briefly discuss their major role related to innate immunity.
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coagulation system, kallikrein-kinin system, complement system, cytokines, defensins, acute-phase proteins
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Assess the role of natural killer cells.
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NK cells are activated by cytokines (interferons) and also by macrophage-derived cytokines. These cells serve as early defense against certain intracellular pathogens, for example viruses.
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PMN, acronym
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polymorphonucleated neutrophil
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polymorphonucleated neutrophils, monocytes, macrophages, eosinophils, and natural killer cells are principally part of what branch of the immune system?
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innate immunity
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Summarize the interplay between innate and adaptive immunity, noting shared aspects of the host's defense mechanisms
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MACROPHAGES and other cells are part of innnate immunity, but produce cytokines that stimulate B and T cells. B- and T-LYMPHOCYTES are part of acquired immunity, but produce cytokines and antibodies that interact with macrophages.
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How long does the innate immune system take to act? The adaptive immune system?
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INNATE: hours. ADAPTIVE: minutes
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PAMPs: acronym, def, ex (2)
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pathogen-associated molecular patterns; conserved structural features expressed by microbes but not by host. Ex. bacterial lipopolysaccharide (LPS), viral double-stranded RNA.
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Receptors that the innate immune system uses to recognize PAMPs: term, ex.
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Innate immune sys recognizes PAMPs via pattern recognition receptors (PRRs), ex. toll-like receptors (TLRs)
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Events following TLR binding to a PAMP? (2)
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1 macrophages release cytokines, 2 all cells activate transcription factors (ex. NF-κβ)
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When a TLR binds to a PAMP, what is the effect on T-cells?
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stimulates release of cytokines, which stimulate T-cells
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What releases TNFα and IL-1?
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tumor necrosis factor-alpha and interleukin-1 are released by macrophages when their TLRs bind LPS or other PAMPs
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What enables the innate immune system to distinguish between self and non-self?
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PAMPs
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NF-κβ: What is it? What processes does it regulate? (4 examples)
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Nuclear transcription factor produced in most cells. Regulates genes for apoptosis, viral replication, inflammation, and autoimmune diseases.
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What can activate NF-κβ? (4)
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growth factors, cytokines, drugs, stress
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"acid mantle", def
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acid pH of sweat and sebaceous glands that protects the skin (pH = 4.5-5.5)
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"respiratory escalator", def
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cilia of the mucous membranes sweep microbes up and out the resp tract
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general term for all mucous membrane environments?
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mucosal-associated lymphoid tissues (MALT)
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Examples of biochemical defenses (4)
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acidity of stomach, lysozyme, pH of vagina, proteolytic enzymes and bile in GI tract
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CLINICAL APPLICATION: Why do children fed infant formula have more diarrhea than children fed on breast milk?
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no lysozyme in formula, so they are more prone to infection
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lysozyme: def, where it is found
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carbohydrase for breaking down peptidoglycan cell wall of Gram(+) bacteria, found in saliva, tears, sweat, human milk, mucus, and specific granules of neutrophils
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CLINICAL APPLICATION: Why do yeast infections develop?
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Vagina becomes too alkaline (usual pH is 3.8-4.5)
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opsonization, def
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augmentation of phagocytic activity by coating with C3b
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What attracts PMNs to the site of injury?
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chemokines
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life span of a neutrophil?
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6-8 hr (short lived)
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selectin, def
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a cell adhesion molecule (CAM) that allows polymorphonucleated neutrophils to adhere to endothelium
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What do you call macrophages in the following locations: liver, lung, peritoneum, brain, skin, lymph node
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Kupffer cells in liver, alveolar macrophages, splenic macrophages, peritoneal macrophages, microglial cells in brain, Langerhans cells in skin, dendritic cells in lymph node
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dendritic cells of lymph node: aka, origin, fxn, location
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AKA: interdigitating dendritic cells (IDCs). ORIGIN: bone marrow APCs. FUNCTION: present antigens to T-lymphocytes. LOCATION: paracortex.
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What is the most important APC?
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B-lymphocyte
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examples of general types of pathogen-recognizing receptors on the surface of macrophages? (2)
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mannose receptor, scavenger receptor
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SRB1, fxn
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scavenger receptor B1; found in the liver, takes up esterified cholesterol in the form of HDLs
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Ways that pathogenic bacteria thwart phagocytes (2)
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polysaccharide capsule inhibits phagocytosis, bacteria in phagosomes inhibit discharge of lysosomal contents, survive inside phagolysosomes
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What are the 2 classes of APCs? What cell types are found in each class?
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1 "professional" APCs that express MHC Class II (macrophages, dendritic cells, B-lymphocytes), 2 "non-professional" APCs that express MHC Class I (all nucleated cells, including fibroblasts, thymic epithelial cells, glial cells)
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What do granulomas and atherosclerosis have in common?
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Both are formed by macrophages. (Macrophages form granulomas during chronic inflammation, form plaque for atherosclerosis)
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General term for molecules of the following systems: coagulation system, kallikrein-kinin system, complement system, cytokines, defensins, acute-phase proteins
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plasma proteins
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CLINICAL APPLICATION: What is the mechanism of action of streptococcus?
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Secretes streptokinase or fibrinolysin.
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How do PMNs use the coagulation system in pathogen defense?
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Degrade coagulation inhibitors to "trap" bacteria in small vessels.
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bradykinin: general class of molecules, what it does
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Kallikrein-Kinins, cause inflammation
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Preview: What are the roles of the complement cascade? (4)
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chemotaxis, opsonization, inflammation, and finally, lysis
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Over 25 proteins and protein fragments make up the complement system, including ______ proteins and ______ proteins, They account for about 5% of the ______ fraction of blood serum.
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Over 25 proteins and protein fragments make up the complement system, including serum proteins, serosal proteins, They account for about 5% of the globulin fraction of blood serum.
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ex. classes of cytokines (
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interleukins, lymphokines, cell signal molecules (ex. TNFα, interferons)
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INF: acronym, fxn
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interferon; trigger inflammation
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Cysteine is usually cationic or anionic?
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cationic
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defensin: distinguishing characteristic of molecular structure? fxn?
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contain a lot of cysteine, found in PMN granules, fxn is to form pores in the microbial cell membrane
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defensin, def
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catch-term for antimicrobial peptides that are stored in a subset of azurophilic granules of PMNs
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2 families of defensins, which cells express them
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ALPHA DEFENSINS: expressed in PMNs and Natural Killer cells. BETA DEFENSINS: secreted by leukocytes, epithelial cells (found on tongue, skin, kidneys, esophagus, respiratory tract)
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are neutrophils APCs?
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NO! Only macrophages are phagocytic and antigen-presenting.
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acute-phase proteins, def
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aka acute-phase reactant; any protein whose plasma concentration changes during inflammatory disorders, ex. CRP
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What are the main cytokines responsible for fever and inflammation? (4)
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IL-1, IL-6, IL-8, TNF-α
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is inflammation a part of the innate or adaptive immune response?
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yes
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What are the roles of C3a, C3b, C5a, and the other complements?
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C3a and C5a: chemotaxis. C3b: opsonization. All complements combined: inflammation.
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inflammation refers to what 3 specific changes at the site of injury?
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1 inc blood supply, 2 inc capillary permeability, 3 inc WBC migration (due to C3a and C5a)
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swelling, redness, heat, pain in Latin?
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tumor, rubor, calor, dolor
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CLINICAL APPLICATION: Clinical sign of pts who lack NK cells?
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constant herpes infections
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Describe how NK cells interact with body cells, including important ligands/receptors involved.
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NK cells have KIR that bind to Class I MHC surface markers, making sure that all cells have Class I MHCs present. If the body cells do not have it, the NK cell lyses them.
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IFNγ, def
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main cytokine released by NK cells
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What are the specific recognition molecules of the adaptive immune response vs. the non-specific receptors of the innate immune response?
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ADAPTIVE: Ig receptors. INNATE: TLRs.
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How does denosumab work?
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A new drug called denosumab acts to raise bone mineral density and reduce fracture rates in many patient sub-groups by inhibiting RANKL. RANKL acts through its receptor RANK, which in turn promotes NF-κB, RANKL normally works by enabling the differentiation of osteoclasts from monocytes.
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Assess the role of natural killer cells.
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NK cells are activated by cytokines (interferons) and also by macrophage-derived cytokines. These cells serve as early defense against certain intracellular pathogens, for example viruses.
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