individuals who already have antibodies against particular pathogen*Good way to fight infection immediate protection immunity only lasts as long as

Individuals who already have antibodies against

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Unvaccinated individual who are exposed to particular agents (hep A, rabies virus) are given immunoglobulins that are prepared form individuals who already have antibodies against particular pathogen*Good way to fight infection, immediate protection, immunity only lasts as long as the antibodies (~2 weeks) > T cells are eventually destroyed5.Evaluate the purpose of the terms and describe the importance to clinical practice.Antigen: Harmful molecule that can react with antibodies or antigen receptors on B and T cellsForeign, “non-self” Viruses, bacteria, fungi, parasitesCan also be found on noninfectious environmental agents (pollens, food, bee venom, drugs, vaccines, transfusions)To function: at least a portion of a molecule’s chemical structure must be recognized by and bound to an antibody and/or to specific receptors on a lymphocyteSelf-antigen: AKA immunogens- can induce immune response resulting in production of antibodies or functional T cells Most individuals tolerant of their own antigensRegulated by T regulatory cells (T reg)Allergens: Antigens that induce an allergic responseAntibody: AKA immunoglobulin (Y shaped protein produced by plasma cells) used by immune system to neutralize pathogens (bacteria/viruses)Recognize a unique molecule of harmful agent called antigenNeutralize bacterial toxins > coat bacteria to enhance phagocytosis > formation of antibody complex > activates complement cascadeACTIVATION OF HUMORAL IMMUNITYB-cells stimulated by release of IL4 > B cells differentiate into plasma cells > produce antibodies > memory B cellsPlasma cells produce antibodies that will bind to the antigen > make antigen-antibody complexesMemory B-cells will act during secondary immune response > remember antigen > respond quicker in initiating the immunoglobulin creating process
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Type of B-Lymphocyte CellFunctionImplications for Clinical Practice IgAFound in secretions/mucous membranes/ blood (IgA 1)-Prevents the attachment of microorganisms to the mucous membranes-Secretions prevent dehydrationIgMProduced early in the primary immune response-Synthesized in neonatal life, may increase as response to infection in utero-High level indicate recent infectionIgGMost prominent immunoglobulin-Binds with viruses, bacteria, toxins (most protective against infections)-Activates complement & binds to macrophages-Primary antibody in the 2ndary immune response-Levels rise in response to exposure to an antigen-Only immunoglobulin that crosses the placenta (major class of antibody found in newborns/fetus)IgELeast concentrated-Binds to mast cells, eosinophils, basophils-Involved in parasitic infections & hypersensitive reactionsMediator of many common parasitic infectionsIgDFound on surface of B lymphocytes, function not understood, limited informationACTIVATION OF T-CELLSAntigen presenting cells include B-lymphocytes, macrophages, and dendritic cells Antigen enters host Macrophage engulfs antigen antigen expressed on MHC class II secretes IL 1 to attract CD4 cells presents it to CD4-cells CD4 differentiates into Th1 and Th2Th1 releases IL2 activated cytoxic T- cells (Tc) Tc receptor connects with MHC classI receptor on invader cytoxic chemicals released invader killed. Th2 releases IL4 activates the humoral immune systemType of T-lymphocyte CellsFunctionT-cytotoxic cells Differentiation of T cells into effector cells -Activated by various cytokines -Attack and kill targets directly by release of cytotoxic chemicals which destroy the cell membrane or induce apoptosisAKA cellular immunityTargets: cells infected by viruses, cancerous cells, allograft cells (transplant tissue)-CD 8 cells (AKA Killer T’s, T8 cells)NK Killer cells Recognition and elimination of cells infected with viruses-Eliminate abnormal host cells (specifically cancer cells)-Inhibitory and activating receptors that allow differentiation between infected/tumor cells & normal cells -Binds to target cell through activating receptors > produces several cytokines & toxic molecules that can kill the targetT-Regulatory cellsSlow/stop immune response once the invader is defeated-Prevents against attacking self-antigens & avoid over activation of the immune responseT-Helper cells Facilitate immune responses by secreting chemical messengers (cytokines)
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  • Fall '15
  • david,mary

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