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26 Cards in this Set
- Front
- Back
1. What are innate immune response?
What are adaptive or acquired immune response? What drives adaptive immune responses? |
Responses that do not involve triggering of antigen-specific receptors on lymphocytes
Responses by specific subsets of lymphocytes Triggering of lymphocytes through receptors that recognize antigens on the targets **Acquired immune response usually result in immunologic memory |
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2. What are the major non-immunologic mechanisms of host defense to microbes?
Five things... |
1. Physical barriers
-skin -epithelial cells that line mucosal surfaces 2. Mechanical clearance mechanisms 3. Chemical barriers 4. Normal flora 5. Chemical antibacterial substances |
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3. What are four mechanical clearance mechanisms?
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1. Ciliary epithelium in bronchial tree
2. Tears 3. Gastrointestinal motility 4. Urinary tract mucous |
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4. What are two chemical barriers?
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1. Low pH of the stomach
-acidity is toxic to many microbes 2. Fatty acid in sweat and sebaceous secretions |
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5. How does the normal flora act as a barrier against pathogens?
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1. Commensal and symbionts that reside in the skin and GI tract
2. Lactic acid in vaginal tract |
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6. What are some chemical antibiotic substances?
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1. Lysozyme in milk, tears, urine, saliva
2. Lactoferrin -iron binding protein in granules of neutrophils 3. Antibacterial peptides secreted from phagocytic and epithelial cells |
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7. What happens the first time you encounter a microbe which you have never seen before?
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1. Innate immune response attempts to control growth of organism
2. Adaptive or acquired immune response appears about a week after the organisms are first encountered *humoral and cellular immune responses that are antigen specific are induced **antibodies and T cells mediate these responses |
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8. What are the first line of defense?
What are PMNs? What do primary or azurophilic granules contain? What do secondary granules have? How is the lifespan of PMNs? |
Polymorphonuclear leukocytes
(PMNs or neutrophils) Preformed granules that have an antibacterial arsenal Myeloperoxidase Lysozyme and lactoferrin Short half-life (1 to 2 days) |
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9. What is the mononuclear phagocyte system?
How are their lifespan? |
Monocyte to macrophage maturation
Long-lived (months to years) |
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10. What cells characterize acute inflammation?
What are examples? How is the progression? What cells characterize chronic inflammation? What are examples? How is the progression? |
PMNs (pus)
Bacterial pneumonia, menigitis Rapid Macrophages & T cells (mononuclear infiltrate) Tuberculosis (granuloma formation) Slow |
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11. How do phagocytes attack microbes?
Three ways... |
1. Phagocytosis
-attachment -ingestion 2. Digestion 3. Microbicidal mechanisms |
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12. How do phagocytes attach to microbes during phagocytosis?
What are examples of receptors on macrophages? What enhances phagocytosis? |
Non-specific interactions
CR3, scavenger receptors, toll-like receptors, CD14 Opsonins (antibodies and complement components) |
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13. What is a phagosome formed during ingestion?
What is a lysosome? What is a phagolysosome? Which one kills microbes most often? |
An invaginated vesicle that pinches off the cell membrane and encloses a microbe
A membranous vesicle that contains enzymes Vesicle formed by the fusion of a phagosome containing a microbe and a lysosome Phagolysosome |
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14. How are most reactive oxygen intermediates formed when neutrophils phagocytize?
When PMNs or macrophages ingest particles what are the metabolic consequences of phagocytosis? (three things) |
Via myeloperoxidase
1. Increase in glycolysis by the hexose monophosphate shunt 2. Increase in uptake of molecular oxygen 3. Increase in production of peroxide |
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15. What is the myeloperoxidase (MPO) system?
What are the two mechanisms? |
Peroxide plus a halide
**microbicidal 1. Bacteria + H2O2 gives... -HOCl (bleach) -MPO 2. Chloramine formed on bacterial surface proteins |
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16. What is chronic granulomatous disease of childhood?
What characterizes this disease? What do patients lack? Therefore production of what is defection? |
X-linked inherited killing defect of PMNs
Characterized by multiple granulomas due to infection Lack NADPH oxidase Superoxide and peroxide |
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17. What can CGD handle?
What are two examples? What are CGD susceptible to? What are three examples? |
Handle normally
-peroxide+ -catalase- Examples: -streptococci -hemophilus Susceptible to: -peroxide+ -catalase+ Examples: -staphylococci -E. coli -Candida albicans |
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18. What gas is a microbicidal molecule generated by activated macrophages?
This combination of this gas plus superoxide produces what? |
Nitric oxide (NO)
Peroxynitrite **microbicidal |
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19. What are cationic proteins?
What do they do? |
Large MW positively charges proteins present in primary granules of PMNS
Bind to outer membrane of gram-positive bacteria and form pores |
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20. What are defensins?
What are lysozymes? What are they mostly in? |
Small MW proteins that have antibiotic properties
**type of host antibiotic Enzymes that break down microbial peptidoglycan in the cell wall Mostly in PMNs |
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21. What are the microbicidal substances in phagocytes?
Six things... |
1. Peroxide
2. Nitric Oxide (NO) 3. Peroxynitrite 4. Cationic proteins (PMNs) 5. Defensins (mostly PMNs) 6. Lysozymes (mostly PMNs) |
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22. What are some digestive enzymes in PMNs?
Seven examples... |
1. Protease (Cathepsin G)
2. Elastase 3. Collagenase 4. Lipase 5. Ribonculease 6. Acid phosphatase 7. Alkaline phosphatase |
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23. What are natural killer (NK) cells?
Do they have antigen-specific receptors like T or B cells? How do they kill target cells? What cells do NK cells attack? Why do they attack these cells? What would NK cells be considered then? |
Large granular lymphocytes
Do not have antigen-specific receptors Kill by direct contact using molecules that are released from preformed granules Either virally infected or tumor cells They fail to express the molecules that activate the NK cell killer inhibitory receptors **MHC Class I is absent so cell is not recognized as self Part of discriminating pathway for telling difference between self and non-self |
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24. What are dendritic cells?
What do they do? When they do this what is initiated? What are dendritic cells considered to be? |
Antigen presenting cells
Capture foreign proteins and present them to T cells Initiate adaptive immune response Bridge between innate and adaptive immuni†y |
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35. Describe the main cell types in acute versus chronic inflammation induced by bacteria.
What is the defect in the PMNs of chronic granulomatous disease patients that prevents them from killing certain microbes? |
Acute: PMN
Chronic: -monocyte -macrophages -lymphocytes In the NADPH oxidase **PMNs cannot make peroxide or superoxide |
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26. What are two peroxide-independent mechanisms by which phagocytes kill microbes?
What is a phagolysosome? Do natural killer cells recognize specific microbial substances? |
Defensins, cationic proteins, NO
Fused vesicle of a phagosome and a lysosome No **recognize absence of molecules that engage their killer cell inhibitory receptors |