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229 Cards in this Set
- Front
- Back
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What type of lymphoid tissue are lymph nodes?
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secondary lymphoid organ: has many afferents, 1 or more efferents
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What is the function of the lymph node? Does it have a capsule?
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Encapsulated
functions: nonspecific filtration by macrophages, storage, and activation of B and T cells, antibody production |
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Where does antibody production occur?
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in the lymph node
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What are the three areas of a lymph node?
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Follicle, medulla, paracortex
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What occurs in the follicle of a lymph node?
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B cell localization and proliferation
in the outer cortex primary follicles are dense and dormant (have not seen antigen) secondary follicles have pale central germinal centers and are active (lymphocytes have seen antigen) |
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What does the medulla of a lymph node include?
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medullary cords (closely packed lymphocytes and plasma cells) and medullary sinuses
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What are the medullary sinuses?
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vessel like spaces that separate the medullary cords - lymph flows into medullary sinuses from cortical sinuses into efferent lymph vessels
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What make up the medullary cords?
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lymphocytes and plasma cells
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What make up the medullary sinues?
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reticular cells (make reticular fibers) and macrophages (histiocytes - immobile macrophages)
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What is in the paracortex? Where is it located?
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houses T cells. It is located between the follicles and medulla
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What type of lymphoid tissue are lymph nodes?
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secondary lymphoid organ: has many afferents, 1 or more efferents
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What is the function of the lymph node? Does it have a capsule?
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Encapsulated
functions: nonspecific filtration by macrophages, storage, and activation of B and T cells, antibody production |
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Where does antibody production occur?
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in the lymph node
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What are the three areas of a lymph node?
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Follicle, medulla, paracortex
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What occurs in the follicle of a lymph node?
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B cell localization and proliferation
in the outer cortex primary follicles are dense and dormant (have not seen antigen) secondary follicles have pale central germinal centers and are active (lymphocytes have seen antigen) |
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What does the medulla of a lymph node include?
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medullary cords (closely packed lymphocytes and plasma cells) and medullary sinuses
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What are the medullary sinuses?
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vessel like spaces that separate the medullary cords - lymph flows into medullary sinuses from cortical sinuses into efferent lymph vessels
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What make up the medullary cords?
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lymphocytes and plasma cells
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What make up the medullary sinues?
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reticular cells (make reticular fibers) and macrophages (histiocytes - immobile macrophages)
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What is in the paracortex? Where is it located?
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houses T cells. It is located between the follicles and medulla
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Where are high endothelial venules? What do they carry?
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located in the paracortex. Where B and T cells enter from the blooc
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What delivers B and T cells from the blood into a lymph node?
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high endothelial venules - in the paracortex of a lymph node
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What part of the lymph node becomes very enlarged during extreme cellular immune response (viral)?
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paracortex
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What part of the lymph node is not well developed in patients with DiGeorge syndrome?
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paracortex - don't really have T cells (no thymus)
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Where does lymph drain from the upper limb and lateral breast?
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axillary lymph nodes
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Where does lymph drain from the stomach?
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celiac lymph nodes
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Where does lymph drain from the duodenum and jejunum?
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Superior mesenteric lymph nodes
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Where does lymph drain from the sigmoid colon?
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Colic - inferior mesenteric lymph nodes
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Where does lymph from the rectum (lower part), anal canal above the pectinate line drain?
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internal iliac lymph nodes
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Where does lymph from the anal canal below the pectinate line drain?
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superficial inguinal lymph nodes
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Where does lymph from the testes drain?
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superficial and deep plexuses - para-aortic lymph nodes
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Where does lymph from the scrotum drain?
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Superficial inguinal lymph nodes
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Where does lymph from the thigh (superficial) drain?
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Superficial inguinal lymph nodes
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Where does lymph from the lateral side of dorsum of foot drain?
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popliteal lymph node
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What does the right lymphatic duct drain?
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right arm and right half of head
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What does the thoracic duct drain?
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everything but the right arm and the right half of the head
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Where does the thoracic duct empty?
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into the brachiocephalic vein
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Where does the right thoracic duct empty?
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into the right subclavian vein
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What are the parts of the spleen?
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arterial supply - bring blood to the spleen
venous drainage - removes blood from the spleen follicle: in the white pulp - where B cells hang out Red pulp - outer edge of spleen - where RBC's hang out PALS: where T cells hang out - near central arteriole marginal zone: outer part of spleen - where APC's hang out |
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What are the sinusoids of the spleen? What are found nearby?
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long, vascular channels in red pulp with fenestrated "barrel hoop" basement membrane. Macrophages are found nearby
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What is found in the periarterial lymphatic sheath of the spleen in the red pulp?
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PALS have T cells!
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What are found with in the white pulp of the spleen?
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follicles that have B cells!
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What do marcophages do in the spleen?
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removed encapsulated bacteria - if you don't have a spleen you have an increased risk of infection by encapsulated bacteria
SHiN (S. pneumoniae, H. influenzae, N. meningititis) |
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What happens if you have splenic dysfunction?
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decrease IgM, decrease complement activation, decrease C3b opsonization, increased susceptibility to encapsulated organisms (SHiN: S. pneumoniae, H. influenzae, N. meningitidis)
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What do you see postsplenectomy?
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Howell-Jolly bodies (nuclear remnants)
thrombocytopenias target cells |
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What happens in the thymus?
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T cell differentiation and maturation. Encapsulated
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Where is the thymus developed from?
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Epithelium from the third branchial pouch
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What does the cortex of the thymus have?
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immature T cells
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What does the medulla of the thymus have?
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pale with mature T cells and epithelial reticular cells and contains Hassall's corpuscles
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Where does positive and negative selection occur?
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In the corticomedullary junction of the thymus
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What cells are part of the innate immune response?
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PMN's, Macrophages, Dendritic Cells, NK cells, complement
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What limb of the immune systems does not have memory?
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innate
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Which limb of the immune system has a fast and nonspecific response?
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innate
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Innate immune system is encoded how?
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Germ-line encoded
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How are parts of the adaptive immune system made?
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V(D)J recombintation during lymphocyte development
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How fast does the adaptive immune system respond? What cells are part of this immune system?
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Response is slow at first, but memory response is faster and more robust.
Consists of B and T cells and circulating antibodies |
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What takes place in Hassall's corpuscles? Where are they located?
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They are in the thymus.
Epithelial cells become centrically compressed and keratinized, possibly the site for removal of apoptotic cells |
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How do T cells develop?
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Happen in the thymus: initially CD4-CD8-, goes through positive selection (if it recognizes MHC I or II) it survives, if it recognizes MHC I becomes CD8+, if recognizes MHC II becomes CD4+ positive, then goes through negative selection (if it recognizes self antigen - presented by Dendritic cells it is killed
only 2% of all T cells survive to maturation |
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Where does positive selection occur?
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cortex of the thymus
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Where does negative selection occur?
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medulla of the thymus
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What are MHC complexes?
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encoded by HLA gene: present antigen fragments to T cells and TCR
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What are the 6 HLA types?
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MHC I: HLA-A, HLA-B, HLA-C
MHC II: HLA-DP, HLA-DQ, HLA-DR |
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Where is MHC I located?
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on all nucleated cells
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What is B2 microglobulin?
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pairs with MHC I (aids in transport to the cell surface): completes the MHC I molecule
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What mediates viral immunity?
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MHC I
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How is antigen loaded onto MHC I?
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loaded in the RER of mostly intracellular peptides
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MHC I presents antigen to what type of cells?
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CD8+ T-cells: T-cytotoxic
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MHC II presents antigen to what type of cells?
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CD4+ T cells: T-helper cells
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What cells have MHC II?
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antigen presenting cells (DC, Macrophage, B-cell)
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How is antigen loaded on MHC II?
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following release of invariant chain in an acidified endosome
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What does invariant chain do?
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Blocks the binding site for peptide on the MHC II complex - once in acidic endosome the invariant chain is released and the peptide is able to bind to the MHC II and travel to the surface to be presented to a CD4+ T-helper cell
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What conditions is HLA-A3 associated with?
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hemochromatosis
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What conditions is HLA-B27 associated with?
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"PAIR"
Psoriasis Ankylosing spondylitis Inflammatory bowel disease Reiters syndrome (urethritis, conjunctivitis, arthritis) |
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What conditions is HLA-B8 associated with?
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Graves' disease
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What conditions is HLA-DR2 associated with?
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MS, hay fever, SLE, Goodpasture's
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What conditions is HLA-DR3 associated with?
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DM type I
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What conditions is HLA-DR4 associated with?
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RA and DM type I
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What conditions is HLA-DR5 associated with?
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pernicious anemia (problem with parietal cells: lack of intrinsic factor) - B12 deficiency, Hashimoto's thyroiditis
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What conditions is HLS-DR7 associated with?
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Steroid-responsive nephrotic syndrome
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What are the major functions of B cells?
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to make antibody, IgG antibodies opsonize bacteria, neutralize viruses, allergy (type I hypersensitivity) IgE, cytotoxic (type II) and immune complex (type III) hypersensitivity: IgG, antibodies can cause organ rejection (hyperacute)
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What are T cell functions?
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CD4+ cells help B cells make antibodies and produce y-interferon, which activates macrophages, kill virus infected cells directly (CD8+ T cells), delayed cell mediated hypersentivity (type IV), organ (allograft) rejection (acute and chronic)
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What does y-interferon do?
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activates macrophages
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What type of cells do NK cells kill? What do they use to kill them?
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Kill virally infected cells and tumor cells
use perforin and granzymes |
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What part of the immune system are NK cells?
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part of innate immunity - lymphoid orgin
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What molecules enhance the activity of NK cells?
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IL-12, IFN-B, IFN-a
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When do NK cells kill?
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When the recognize cells that don't have MHC molecules on them they kill or when they get a nonspecific activation schedule on a target cell
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What is the CD3 complex?
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On T-cells - a cluster of polysaccharides associated with the TCR - important in signal transduction
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What is involved in signal transduction for the TCR?
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CD3 complex!
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What are APC's?
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macrophages, B-cells, DC
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what do activated lymphocytes release? what does this substance do?
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Lymphocytes release IFN-y - which stimulates macrophages and macrophages release IL-1 and TNF-a which stimulates lymphocytes
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what does CD4+ T-cells release?
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IL-4, IL-5: stimulates B-cells
IL-2, IFN-y: stimulates CD8+ T cells IFN-y: sitmulates APC's IL-2: stimulates itself |
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What stimulates a CD4+ T cell? What releases it?
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IL-1, TNF-a released from APC
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What CD's does a B cell have?
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CD19 and CD20
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What do CD4+ T cells do?
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help recruit other cells! B cell, cytotoxic T cells, APC's
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What do superantigens do? What bugs produce super antigens?
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S. aureus and S. pyogens - they cross link the B-region on the TCR to the MHC II complex on APC - cause stimulation of many lines of T cells! Get uncoordinated release of IFN-y from Th1 cells and release of IL-1, IL-6 and TNF-a from macrophages
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What does superantigens cause to be released?
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IFN-y from Th1 cells
IL-1, IL-6, TNF-a from marcophages *the massive cytokine release can be deadly |
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What do endotoxins/LPS do to the immune system?
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Directly stimulates macrophages by binding to endotoxin receptor CD14; Th cells are not involved
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Are Th cells involved in endotoxin/LPS affect on immune system?
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NO!
The endotoxin directly binds to macrophages (CD14) |
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What can massive TNF-a release cause?
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shock and multi-organ failure: this is what can happen when someone is infected with a bug that produces a super antigen (S. aureus, S.pyogens)
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What needs to happen for a Th cell to be activated?
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1. foreign antigen must be endocytozed by APC
2. foreign antigen presented on surface of APC by MHC II complex - this is recognized by a TCR on a Th cell (signal 1) 3. costimulatory signal is given by the interaction of B7 (APC) and CD28 (on the Th Cell) - second signal 4. Th cell activated to produce cytokines! |
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Ultimately what does the Th cell do?
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produce cytokines to activate other cells
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What are the signals needed to activate a T cytotoxic cell?
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1. endogenously synthesized (self or viral) are presented on MHC I on any nucleated cell - recognized by TCR on T cytotoxic cell: signal 1
2. IL-2 from Th activates Tc cell to kill virus infected cell: signal 2 2. |
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What are the signals needed for B cells to class switch?
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1. IL-4 (IgE), IL-5 (IgA), or IL-6 from Th2 cell (signal 1)
2. CD40 receptor (on B cell) activation by binding CD40 Ligand on Th cell |
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What are the 2 types of Th cells?
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Th1 and Th2
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What do the different Th cells release?
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Th1 (cell-mediated response): makes IL-2, IFN-y and activates macrophages and CD8+ T cell; inhibited by IL-10
Th2 (humoral response): makes IL-4, IL-5, IL-10 and helps B cells make antibody; inhibited by IFN-y |
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What is Th1 cell inhibited by?
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IL-10
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What is a Th2 cell inhibited by?
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IFN-y
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What cell has CD40 Ligand?
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T helper cell
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What cell has CD40?
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B-cell
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What are the parts of an antibody?
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Fab - where the antigen binds - light and heavy chains are involved
Fc - part that fixes complement - only heavy chains are involved: determine what type of antibody it is (made up of only constant regions) |
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What does the Fab part of an antibody do?
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Determines idiotype: unique antigen binding pocket; only 1 antigenic binding pocket made by a single B cell (one B cell makes one antibody specific for an antigen)
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What does the Fc part of an antibody do?
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Constant, carboxyl terminal (at the end), complement binding (at Ch2 only IgM and IgG), carbohydrate side chains, Determines isotype (IgM, IgD, IgG etc.)
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Where is the carboyxl and amino terminal on an antibody?
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carboxyl is at the bottom of the antibody
amnio is at the end of the y arms of the antibody |
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what type of bond connects the Fc regions of the antibody right before the y arms branch off?
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interchain disulfide bond
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What type of bond connects the Fc heavy chains at the bottom on the same side of the antibody?
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intrachain disulfide bonds
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What are the three functions of an antibody?
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1. Opsonization - promotes phagocytosis (sprinkles on a donut)
2. Neutralization - antibody prevents bacterial adherence 3. Complement activation - antibody activates complement, enhancing opsonization and lysis |
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What does the Fc receptor bind to when a particle is getting phagocytozed?
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Fc portion of the antibody binds to the Fc receptor on the phagocyte
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What are the 4 things that create antibody diversity?
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1. Different combinations of V(D)J
2. Different combinations of heavy and light chains 3. Somatic hypermutation of hypervariable regions 4. addition of nucleotides to DNA during "recombination" by terminal deoxynucleotidyl transferase |
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What are the genes involved in making a heavy chain?
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V,D,J
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What are the genes involved in making a light chain?
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V,J
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What does terminal deoxynucloeotidyl transferase do for antibodies?
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Is one of the ways you get antibody diversity. It adds nucleotides during recombination (of V(D)J genes)
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What types of antibody does mature lymphocytes express on their surfaces?
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IgM, IgD
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How are IgA, IgE, IgG produced?
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class switching (alternative spilicing of mRNA); mediated by cytokines and CD40 ligand into plasma cells that secrete IgG, IgA, IgE
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What is the main antibody in secondary (delayed) response to an antigen?
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IgG - it is the most abundant antibody
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What is the antibody that fixes complement and can cross the placenta?
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IgG (provides infant with passive immunity)
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What does IgG do for an infant?
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provides it with passive immunity
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What does IgG do?
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fixes complement, crosses the placenta, opsonizes bacteria, neutralizes bacteria and toxins
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What antibody inhibits attachment of bacteria and viruses to mucous membranes? Does it fix complement?
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IgA - it does not fix complment
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What type of molecules is IgA?
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monomer in circulation and a dimer when secreted
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Where can IgA be found?
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In tears, saliva, mucous and breast milk (colostrum)
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Where does IgA pick up the secretory component?
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from epithelial cells before secretion
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What is the first antibody produced against an antigen?
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IgM - primary response to an antigen
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What antibody fixes complement but does not cross the placenta?
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IgM (doesn't cross because it is too large)
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Where is the antigen receptor of IgM?
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on the surface of B cells - can be a monomer or a pentamer on B cells
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What shape is IgM usually in?
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usually a monomer or pentamer on B cells
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What is the shape good for of IgM?
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Pentameric shape can efficiently trap free antigens out of tissue while humoral response evolves (agglutination)
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What is the function of IgD, where is it found?
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unclear function - found on the surfaces of many B cells in serum
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What does IgE do?
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Binds to mast cells and basophils; cross-links when exposed to allergen, mediating immediate (type I) hypersensitivity response by releasing inflammatory mediators (histamine)
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What antibody has the lowest concentration in the serum?
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IgE
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What type of bugs does IgE protect immunity?
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worms by activating eosinophils
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What antibodies can fix complement?
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IgG, IgM
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What are antibody isotypes?
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IgA, IgE, IgG, IgD, IgM - the Ig epitope common to a single class of Ig (5 classes; determined by heavy chain)
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What are antibody allotypes (polymorphism)?
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Ig epitope that differs among members of a same species (different alleles of IgM) Can be on heavy or light chains
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What are antibody idiotypes?
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they are specific for a given antigen - Ig epitope determined by antigen-binding sites (idio = unique)
(aka: the uniques variances in the Ig where antigens bind) |
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What are examples of thymus independent antigens?
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antigens that lack peptide components; cannot be presented on MHC cells to T cells (e.g. LPS, polysaccharide capsular antigen). They stimulate the release of IgM antibodies only and do not result in memory
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What do thymus independent antigens cause to be release?
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IgM antibodies: no memory produced
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What are thymus dependent antigens?
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They are antigens with a peptide component (e.g. H influenzae vaccine) Class switching and immunologic memory occur as a result of direct contact with B cells with Th Cells (CD40 and CD40 ligand interaction) and release of IL-4, IL-5, and IL-6
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What is IL-1 secreted by? What does it do?
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macrophages: causes acute inflammation, recruits leukocytes; activates endothelium to express adhesion molecules, and endogenous pyrogen
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What IL is an endogenous pyrogen?
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IL-1
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What releases IL-2?
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Th cells. Stimulates growth of Th and Tc cells
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What do the first 5 IL's do?
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Hot T-Bone stEAk
IL-1. acute inflammation (fever): made by macrophages IL-2: stimulates T-cells (helper and cytotoxic) released by Th cells |
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What is the first antibody produced against an antigen?
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IgM - primary response to an antigen
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What antibody fixes complement but does not cross the placenta?
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IgM (doesn't cross because it is too large)
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Where is the antigen receptor of IgM?
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on the surface of B cells - can be a monomer or a pentamer on B cells
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What shape is IgM usually in?
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usually a monomer or pentamer on B cells
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What is the shape good for of IgM?
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Pentameric shape can efficiently trap free antigens out of tissue while humoral response evolves (agglutination)
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What is the function of IgD, where is it found?
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unclear function - found on the surfaces of many B cells in serum
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What does IgE do?
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Binds to mast cells and basophils; cross-links when exposed to allergen, mediating immediate (type I) hypersensitivity response by releasing inflammatory mediators (histamine)
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What antibody has the lowest concentration in the serum?
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IgE
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What type of bugs does IgE protect immunity?
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worms by activating eosinophils
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What antibodies can fix complement?
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IgG, IgM
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What are antibody isotypes?
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IgA, IgE, IgG, IgD, IgM - the Ig epitope common to a single class of Ig (5 classes; determined by heavy chain)
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What are antibody allotypes (polymorphism)?
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Ig epitope that differs among members of a same species (different alleles of IgM) Can be on heavy or light chains
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What are antibody idiotypes?
|
they are specific for a given antigen - Ig epitope determined by antigen-binding sites (idio = unique)
(aka: the uniques variances in the Ig where antigens bind) |
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What are examples of thymus independent antigens?
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antigens that lack peptide components; cannot be presented on MHC cells to T cells (e.g. LPS, polysaccharide capsular antigen). They stimulate the release of IgM antibodies only and do not result in memory
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What do thymus independent antigens cause to be release?
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IgM antibodies: no memory produced
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What are thymus dependent antigens?
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They are antigens with a peptide component (e.g. H influenzae vaccine) Class switching and immunologic memory occur as a result of direct contact with B cells with Th Cells (CD40 and CD40 ligand interaction) and release of IL-4, IL-5, and IL-6
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What is IL-1 secreted by? What does it do?
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macrophages: causes acute inflammation, recruits leukocytes; activates endothelium to express adhesion molecules, and endogenous pyrogen
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What IL is an endogenous pyrogen?
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IL-1
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What releases IL-2?
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Th cells. Stimulates growth of Th and Tc cells
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What do the first 5 IL's do?
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Hot T-Bone stEAk
IL-1. acute inflammation (fever): made by macrophages IL-2: stimulates T-cells (helper and cytotoxic) released by Th cells IL-3: stimulates bone marrow (secreted by activated T cells) IL-4: stimulates production of IgE and IgG (made by Th2 cells) IL-5: stimulates production of IgA (made by Th2 cells) |
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What secretes IL-3? What does it do?
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secreted by activated T cells. It stimulates growth and differentiation of the bone marrow stem cells. Has a similar function to GM-CSF
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What secretes IL-4? What does it do?
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secreted by Th2 cells. promotes growth of B cells. enhances class switching to produce IgE and IgG
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What secretes IL-5? What does IL-5 do?
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secreted by Th2 cells. Promotes differenetiation of B cells. Creates class switching to make IgA. Stimulates the activation and production of Eosinophils
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What stimulates the production of eosiniophils?
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IL-5
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What secretes IL-6? What does IL-6 do?
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Secreted by Th cells and macrophages. IL-6 stimulates the production of acute-phase reactants and immunoglobulins
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What stimulates the production of acute phase reactants and immunoglobulins?
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IL-6
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What secretes IL-8? What does IL-8 do?
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Macrophages secrete it. IL-8 attracts neutrophils (major chemotactic factor)
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What is a major chemotactic factor for neutrophils?
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"Clean up on isle 8, pmn are recruited to clean up!"
IL-8! secreted by macrophages |
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What secretes IL-10? What does IL-10 do?
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secreted by regulatory T cells inhibits the actions of activated T-cells. Activates Th1, inhibits Th2
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What IL activates Th1 and inhibits Th2?
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IL-10
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What secretes IL-12? What does IL-12 do?
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secreted by B cells and macrophages. IL-12 activates NK cells and Th1
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What IL activates NK cells and Th1?
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IL-12
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What secretes IFN-y? What does IFN-y do?
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It is secreted by Th1. IFN-y stimulates macrophages. Activates Th1 and inhibits Th2
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What cytokines have opposite effects?
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IL-10 and IFN y
IL-10 stimulates Th2 cells, inhibits Th1 cells IFN-y stimulates Th1 cells, inhibits Th2 cells |
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What releases TNF? What does TNF do?
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Secreted by macrophages . TNF mediates septic shock. causes leukocyte recruitment, vascular leak
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What cytokine mediates septic shock? What releases it?
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TNF, released by macrophages
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What cell surface protein is on all mature cell except RBC's?
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MHC I (on all nucleated cells)
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Receptors for MHC I, CD16 (binds fc of IgG), CD56 are on what type of cells?
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NK cells
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What cell surface proteins are found on macrophages?
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MHC I, MHC II, B7, CD40, CD14, Receptors for Fc and C3b
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What cell surface proteins are found on B cells?
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CD20, CD19, CD40, MHC I, MHC II, CD21 (receptor for EBV), IgM, B7
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What is the receptor for EBV?
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CD21 (on B cells) EBV infects B cells
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What type of cells is B7 found on?
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APC: macrophages, DC, B cells
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What type of cell surface proteins are on T cytotoxic cells?
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TCR, CD8, CD3
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What type of cell surface proteins are on T helper cells?
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CD4, CD3, TCR, CD40L, CD28
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What helps prevent complement activation on self-cells?
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C1 esterase and decay accelerating factor (DAF)
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If you have a deficiency in C1 esterase what will the person look like?
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hereditary angioedema (really swollen face)
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What activates the classical complement pathway?
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antibody binding to antigen
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What activates the mannose binding lectin pathway?
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binds microbial surfaces (mannose)
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What activates the alternative complement pathway?
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microbial surfaces (endotoxin, LPS etc.)
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What is the sequence of events for the classical pathway? Where does mannose binding lectin pathway come in?
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antigen bound to antibody starts the process - C1 is activated - C2 and C4 cleaved to C4b2a (C3 convertase), that cleaves C3 - forms C4b2a3b (C5 convertase) that cleaves C5 - C5(a) chemotactic factor while C5b pairs with C6,7,8,9 to form MAC (C5b,C6,7,8,9) - which lyses
mannose binding lectin pathway has a protease that cleaves C4 and C2 - then has same pathway as classical |
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What complement factors neutralize viruses?
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C1,2,3,4
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What complement component opsonizes bacteria?
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C3b
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What complement component causes anaphylaxis?
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C3a, C5a
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What does the MAC protect against?
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gram - bacteria (especially Neisseria)
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What are two primary opsonizens?
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IgG and C3b
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What are the neutrophil chemotaxic factors?
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C5a
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If you have a deficiency in C3 what would a person have?
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recurrent severe pyogenic sinus and respiratory tract infections - increased susceptibility to type III hypersensitivity reactions
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What if you are deficient in DAF (GPI anchored enzyme)?
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leads to complement mediated lysis of RBC's and paroxysmal nocturnal hemoblobuinuria
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What is the process of activation for the alternative pathway?
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Microbial surface (endotoxin) starts process - cleaves C3,B,D - makes C3bBb (C3 convertase) - breaks down C3 and forms C3bBbC3b (C5 convertase) - which breaks down C5 and meets up with other pathways to form C5b,6,7,8,9 (MAC)
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What does MAC do?
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cell lysis and cytotoxicity
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What is the most common complement deficiency?
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C3 deficiency - leads to recurrent and severe pyogenic sinus and respiratory infections
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What are interferons? When are they made?
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A group of proteins produced in response to viral infections (and LPS). Put uninfected cell at in an anti-viral state
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What do interferons release?
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A ribonuclease that inhibits viral protein synthesis by degrading viral mRNA (but does not harm host mRNA)
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What does a and B interferon do?
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Inhibit viral protein synthesis
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What does y interferon do?
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stimulates macrophages and increases MHC I and II expression and antigen presentation in all cells
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What does interferon do for NK cells?
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activates NK cells to kill virus infected cells (cells that don't have self MHC get killed)
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What is active immunity?
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slower, but you get memory
when you inject a safe antigen into an individuals and the individual makes antibodies against the antigen (will protect person if they get an infection with the bug) how immunizations work |
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What is passive immunity?
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quick immunity but NO memory is produced
just give the person antibody! ex. IgA in breast milk |
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What are examples of passive antibodies given after exposure?
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To Be Healed Rapidly
Tetnus, Botulinum, HBV, Rabies all examples of passive immunity also IgA in breast milk is an example of passive immunity |
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IgA in breast milk is an example of what type of immunity?
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passive
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What are classic examples of antigen variation in bacteria?
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Salmonella (has 2 flagellar variants), Borrelia (relapsing fever), Neisseria gonorrhea (pilus protein)
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What are classic examples of antigen variation in viruses?
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influenza (major - shift: minor - drift)
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What are classic examples of antigen variation in parasites?
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trypanosomes (programmed rearrangement)
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What are some mechanisms for antigen variation in species?
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DNA rearrangement and RNA segment reassortment (in influenza - major shift)
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What is anergy?
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A state when B and T cells become inactive
T cells can do this if they do not receive a co-stimulatory signal B cells can becomes anergic too but it is less complete than with T cells |
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What are the infections that can cause granulomas?
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F TB SSCCL
Fungal infections (ex. histoplasmosis) TB Berylliosis Sarcoidosis Syphilis Crohn's disease Cat scratch fever (from bartonella hensle) Leprosy |
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What are the components of a granuloma?
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lymphocytes, fibroblasts, epithelial giant cells (macrophages)
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How does a giant cell get stimulated to be made? Where do you find them?
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APC stimulates Th cell - Th cell releases IL-2 and IFN y
The INF-y activates monocytes - change into macrophages, macrophage change into the epithelial cells, and epithelial cells change into giant cells |
