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73 Cards in this Set
- Front
- Back
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pathogen
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microbe that causes disease
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antigen
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material (from a pathogen) that induces an immune response
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innate (natural) immunity
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rapid, non-specific immune response
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adaptive (acquired) immunity
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slower, specific immune response
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leukocytes
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blood cells
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lymphocytes
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specialized blood cells that mediate adaptive immunity
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Primary lymphoid organs
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where the cells of the immune system arise
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secondary lymphoid organs
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where the cells of the immune system interact with antigens
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thymus
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primary lymphoid organ for T-cell development
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bone marrow
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primary lymphoid organ for B-cell development
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Thymus
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Primary lymphoid organ for T-cell development
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Bone marrow
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primary lymphoid organ for B-cell development
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Lymph node
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collect antigens from tissues
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spleen
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collects antigens from blood stream
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innate immune cells
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macrophage, neutrophils, and dendritic cells
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Adaptive immune cells
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T-cells and B-cells
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T-helper cells
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regulates other immune cells
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T-cytotoxic (killer) cells
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kill infected cells
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B-cells
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produce antibodies (immunoglobulin)
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dendritic cells and macrophage
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directly kill microbes by phagocytosis and other mechanisms. They also help to activate T-cells
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NK cells
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lymphocytes that have characteristics of innate/adaptive immunity
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macrophage function
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phagocytosis and activation of bactericidal mechanisms; antigen presentation
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dendritic cell function
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antigen uptake in peripheral cells; antigen presentation
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mast cell function
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release of granules containing histamine and active agents
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neutrophil functions
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phagocytosis and activation of bactericidal mechanisms
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Eosinophil function
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killing of antibody-coated parasites
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basophil function
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unknown function
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Immune effector mechanisms:
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1. phagocytosis
2. cytotoxicity (cellular killing) 3. complement 4. antibodies |
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Complement
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group of serum proteins that can directly kill pathogens
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Antibodies
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proteins secreted by B-cells that bind directly and specifically to pathogens. Antibodies target pathogens by marking them for destruction by other components of the immune system
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The Danger Theory
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pathogens cause damage to tissues, which leads to the release of alarm signals that trigger immune responses
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Pattern recognition theory
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pathogens contain molecular patterns that differ from host cells "pathogen-associated molecular patterns" or PAMPs. These can be recognized by immune cells using specific receptors
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cytokines
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small secreted peptides that used for intracellular communication between cells of the immune system. Can turn on/off immune responses; mediate inflammation
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chemokines
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subset of cytokines that specialized in regulating cell motility
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inflammation
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a complex series of events induced by tissue damage
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chemotaxis
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neutrophils (white blood cells) are attracted to bacterial chemical products like the peptide f-LMP
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Powerful methods for detecting and quantitating proteins and cells based on the highly specific binding of antibodies (immunoglobulin)
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1. ELISA
2. Western blot 3. Flow cytometry |
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Western blot
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Separate proteins by size using SDS-PAGE gel
Transfer gel to blotting membrane Probe membrane with antibody specific for protein of interest Detect bound antibody by chemiluminescence |
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Defensins
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originally isolated from frog skin based on their ability to kill bacteria; small polypeptides secreted at mucosal surfaces; direct bacteriocidal properties
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Phagocytosis steps
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1. bacterium attaches to membrane
2. bacterium is ingested, forming phagosome 3. phagosome fuses with lysosome 4. lysosomal enzymes digest the bacteria 5. digest material is released from cell |
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apoptosis
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programmed cell death
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NF-kB
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a transcription factor which binds to antibody genes
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TLR
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toll-like receptors (TLR)
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what are the non-covalent forces that hold antigen and antibodies together?
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1. electrostatic forces
2. hydrogen bonds 3. van der waals forces 4. hydrophobic forces |
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epitope
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three-dimensional face of an antigen which makes contact with the antibody
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conformation epitopes
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only epitopes when in their native form
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neutralization
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binding itself prevents pathogenesis
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opsonization
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enhances phagocytosis
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IgG
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Predominant Ig in serum
4 subclasses (1-4) Important for opsonization, complement activation, ADCC Crosses placenta to protect fetus |
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IgM
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pentameric (decavalent)
Pentameric structure held together by J-chain and disulfide bonds First Ig produced in response to infection Good at complement activation |
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IgA
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dimeric predominant Ig in secretion
Transported across epithelial cells via poly-Ig receptor 10 g of IgA secreted/day, more than any other Ig Found in breast milk, supplies passive immunity to baby |
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IgE
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present in very low amounts in serum
Binds to Fc receptors present on mast cells and basophils levels increase in setting of parasitic infection Can transfer allergy between individuals |
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immunogens
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a substance that elicits an immune response
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antigen
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substance that is recognized by the immune system
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hapten
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a small molecule that by itself cannot induce an immune response but can be an antigen
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Factors affecting immunogenicity:
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1. foreigness
2. size 3. complexity 4. susceptiblity 5. genotype of host 6. route of administration 7. dose |
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polyclonal antibodies
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antibody preparation from immunized animals. Consist of complex mixtures of different antibodies produced by many different B-cell clones
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monoclonal antibodies
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homogenous antibody preparation produced in the laboratory. Consist of a single-type of antigen binding site, produced by a single B-cell clone
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Affinity
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refers to the strength of bind of single epitope to single antigen binding site
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avidity
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strength of binding; affected by both affinity and the valence of the interaction (number of interacting binding sites)
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adjuvants
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things that enhance the immunogenicity of antigens by: triggering the innate immune system, slowing release of antigen, promoting phagocytosis of antigen
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secondary antibodies
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antibodies that bind to other antibodies
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isotypic determinants
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secondary antibodies that recognize portions of the constant regions that are characteristic of a particular antibody isotype
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allotypic determinants
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secondary antibodies that recognize portions of the antibody that are variable between different individuals (different allotypes) in the species
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idiotypic determinants
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some secondary antibodies recognize unique portions of the variable domain of the antibody: the antigen-binding sites (idiotypes). Anti-idiotypic antibodies are rare
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promoters
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relatively short nucleotide sequences within ~200 bp of transcriptional start site that initiate transcription in a certain direction
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enhancer
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nucleotide sequences located upstream or downstream of a gene that activated the promoter in an orientation independent manner
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12/23 rule
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only gene segments flanked by RSSs with dissimilar spacers can undergo VDJ recombination wtih one another.
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functions of complement
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1. opsonization
2. provoke inflammation 3. poke holes in membranes of bacteria 4. clear immune complexes 5. activate antigen-specific B-cells |
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classical pathway (complement)
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antigen-antibody complexes
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lectin pathway
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mannose binding lectin or ficolin binds carbohydrates on pathogen surfaces
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alternative pathway
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pathogen surface
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CD19
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B-cell specific transmembrane protein; Ig superfamily member, large cytoplasmic domain binds to signaling molecules; associates in membrane with CR2, alters signaling properties of BCR
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