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34 Cards in this Set
- Front
- Back
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Name 3 roles of the immune system
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1) eliminate microbes
2) immune surveillance vs. cancer 3) remove apoptotic cells |
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Name 3 main mucosal surfaces that bacteria can penetrate
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airway - spores
GI tract - contaminated food/water reproductive tract - physical contact |
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Name 3 external epithelia where bacteria can establish residency
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1)external surface (skin)- Athlete's foot
2) wounds + abrasions 3) insect bites |
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Name 4 classes of pathogens that the immune system can protect against
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extracellular bacteria/parasites/fungi
intracellular bacteria/parasites viruses (intracellular) parasitic worms |
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1) 1st use of modern vaccination by who?
2) who demonstrated that microorganisms cause disease? 3) father of immunology? |
1)Edward Jenner--cowpox (vaccinia)
2) robert koch - diff microbes cause diff disease; believed that microbes were invariant (not right! - proven wrong by Pasteur) 3) louis pasteur |
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What did Pasteur prove about microbes?
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-debunked sponatenous generation theory; concept of attenuation- used to innoculate pts (microbes are not invariant)
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Who demonstrated the existence of phagocytes?
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Metchnikov; first observed in starfish larvae. detected these in human blood + organisms.
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Who developed the idea of passive serum therapy?
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von Behring + Kitasato. can take antibodies, transfer them, and transfer immune function. Ex. serum from animals immune to diptheria , transfer, naiive animal is protected vs. diptheria (specificity)
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Hybridoma?
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take plasma cells (B cells) and immortalize it which generates antibodies. Introduce these into people through injections.
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Who lysed the bacterium vibrio cholerae?
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J. Bordet and complement. heat immune system + fresh non-immune = lysis.
(heat resistant + heat labile - 2 components that you need in immune system) |
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Who discovered the idea of antibodies?
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K. Landsteiner - antibodies can discriminate detailed chemical structure.
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Describe antibody structure
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4 chains - 2 light and 2 heavy.
bound together by disulfide bonds. variable chain - recognizes seq that bacteria is specific for. D region - constant region J region - joins the 2 together |
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mechanisms of antibody function
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1) create oxidants
2) immunomodulation 3) opsonization - antibodies recognized and can be phagocytosed. 4) activation of complement - 5) virus and toxin neutralization 6) antibody-dependent cell cytotoxicity- recognized by killer T cells 7) direct antimicrobial activity - directly binds and inactivates it 8) reduced damange to host from inflammatory response |
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what's a problem of adaptive immunity?
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making antibodies to self.
Paul ehrlich - concept of autoimmunity |
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phases
1) lag 2) response to antigen 3) secondary response. What is different about the reaction to the 1st antigen versus the 2nd one that is just introduced? |
1) antigen and anibody first exposed- nothing happens (regulated by innate immunity)
2) increase in antibodies eventually will plateau 3) rapid response vs. 1st antigen, but response vs. 2nd antigen is almost null. secondary responses show receptor specificity/memory |
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what's immunological memory - i.e. tenants of clonal selection hypothesis?
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primary and secondary responses have qualititative and quantitve differences.
Clonal selection - the clone recognizes a specific antigen. effector cells will eliminate teh antigen. Each lymphocyte bears a single type of receptor with a unique specificity. Receptor occupation is required for cell activation. The differentiated effector cells derived from an activated lymphocyte will bear receptors of identical specificity as the parental cell. Those lymphocytes bearing receptors for self molecules will be deleted at an early stage. |
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What occurs with self-reactive immature lymphocytes?
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usually are removed through clonal deletion first by creating a very strong signal. select against autoreactive cells because the receptor-binding to the signal surfance (antigen) is weakly bound.
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immunogen? adjuvant?
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antigens that induce immune response. antigens are recognized by the antibody.
adjuvant- required for immunogenicity. need this to induce the innate immune response. a pharmacological or immunological agent that modifies the effect of other agents (e.g., drugs, vaccines) while having few if any direct effects when given by itself. |
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what are the most immunogenic?
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proteins! lipids, nucleic acids, polysaccharides are antigenic but can be immunogenic
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antigenic determinant/ epitope?
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Binding site on an antigen. can be simple (linear) or (complex) confirmational.
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What are some innate responses?
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immune systems respond to pathogen associated pattern. allows for very rapid speed in response; non-specific - want to have robust early response w/o having to adapt to it ; germ line receptors ; lack of memory
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B- cell and T cell developement location (primary system)
Secondary system? teritary system |
Bone marrow. T cells then migrate to thymus to develop more.
2) lymphocytes- spleen, lymph nodes, bone marrow? Get expanision of adaptive immune system 3) skin, mucosa, pleural cavity, liver |
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How to lymphocytes and lymph return to the blood?
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through the thoracic duct
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What does activation of the lymphocyte require prior?
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activation of the innate immune system that serves as endogenous adjuvants. the antigen alone is insufficient.
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What are 2 things that are released by innate cells?
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released by chemokines and cytokines
chemokines: attract cells to a site (out of blood, lymph, or within an organ) cytokines: affect behavior of cells (proliferation, differentiation, cytokine production) -innate immune cell fcn is needed for activation of adaptive immunity |
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What fluid drains into the spleen?
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lymph fluid drains into tiny lymphatic vessels.
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Where are Peyer's patches found + how do they come into contact w/ antigens?
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They are aggregations of lymphoid tissue that are usually found in the lowest portion of the small intestine ileum in humans; as such, they differentiate the ileum from the duodenum and jejunum
Pathogenic microorganisms and other antigens entering the intestinal tract encounter macrophages, dendritic cells, B-lymphocytes, and T-lymphocytes found in Peyer's patches and other Mucosa Associated Lymphatic Tissue (MALT). |
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What are the cells of the innate immune system?
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macrophages, neutrophil, eosinophil, basophil, mast cell, natural killer cells (NK) cells - relases lytic granules that kill some virus infected cells, dendritic cells (professional antigen presenting cells - myeloid DC and plasmacytoid DC)
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Besides cytokines and chemokines, describe 2 other soluble components of the innate immune system
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1) defensins - small cysteine-rich cationic proteins found in both vertebrates and invertebrates. They have also been reported in plants. They are active against bacteria, fungi and many enveloped and nonenveloped viruses. They consist of 18-45 amino acids including six (in vertebrates) to 8 conserved cysteine residues. Cells of the immune system contain these peptides to assist in killing phagocytized bacteria, for example in neutrophil granulocytes and almost all epithelial cells. Most defensins function by binding to the microbial cell membrane, and, once embedded, forming pore-like membrane defects that allow efflux of essential ions and nutrients.
2) mannose binding lectin - MBL belongs to the class of collectins in the C-type lectin superfamily, whose function appears to be pattern recognition in the first line of defense in the pre-immune host. MBL recognizes carbohydrate patterns, found on the surface of a large number of pathogenic micro-organisms, including bacteria, viruses, protozoa and fungi. B |
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What system can be recruited and activated by the adaptive immune system?
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complement system
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3 pathways of the complement system?
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1) classical pathway - antigen:antibody complexes on pathogen surfaces
2) lectin pathway - MBL or ficolin binds carbohydrate on pathogen surfaces 3) alternative pathway - directly on pathogen surfaces |
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What's the basic function of the complement system
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The complement system consists of a number of small proteins found in the blood, generally synthesized by the liver, and normally circulating as inactive precursors (pro-proteins). When stimulated by one of several triggers, proteases in the system cleave specific proteins to release cytokines and initiate an amplifying cascade of further cleavages. The end-result of this activation cascade is massive amplification of the response and activation of the cell-killing membrane attack complex. Over 25 proteins and protein fragments make up the complement system, including serum proteins, serosal proteins, and cell membrane receptors. They account for about 5% of the globulin fraction of blood serum.
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How can antibodies mediate precipitation and agglutination reactions?
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Each antibody recognizes a specific antigen unique to its target. By binding their specific antigens, antibodies can cause agglutination and precipitation of antibody-antigen products, prime for phagocytosis by macrophages and other cells, block viral receptors, and stimulate other immune responses, such as the complement pathway.
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What is 'immunological memory'?
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Recall responses are referred to as immunological memory. memory is specific for the priming antigen.
2ndary response is faster (shorter lag period) w/ a greater amplitude |
