Lecture 311. Learn the general innate immunity mechanisms that protect against pathogensa. Define: Preexisting ability to recognize pathogens or their toxins and destroy or inactivate them:i. Innate immunity is carried out by cells known as phagocytesii. Specialized blood cells- engulf and kill most pathogens 2. Be able to recognize the three main functions of adaptive immunity a. Define: Relies on previous exposure to a pathogenb. Main Functionsi. Recognize a pathogen and their toxinsii. Discriminate between a pathogen and normal body cellsiii. Eliminate the pathogen and/or toxin3. Know what an antigen isa. Any molecule or portion of a molecule that stimulates a response in immune system; examples include proteins, polysaccharides 4. Know how phagocytes recognize pathogens at the molecular level a. Phagocytes recognize pathogen-associated molecular patterns- structuresthat are part of the cell of many commonly encountered pathogensb. This recognition occurs through pattern recognition receptors- on surface of phagocytesi. After contact with PAMP, phagocyte becomes activated to ingest and destroy the pathogenii. Molecular pieces of the pathogen are then attached to protein complexes and presented on the cell surface 5. Briefly describe how phagocytes destroy pathogens a. Phagocytes ingest pathogens and present antigens on their surface. These are recognized by T cells. B cells also recognize antigens and produce antibodiesb. T cell cause tissue inflammation and kill infected host cells c. B cells stimulate T2 cells that stimulate B cells to produce antibodies 6. Know what a T-cell receptor isa. T-cells recognize a single specific antigen, which binds to the T-cell receptors 7. Be able to briefly describe how an antigen is presenteda. Present on a protein complex the major histocompatibility complex8. Be familiar with how T-cells are stimulated upon binding to antigen-presenting cell and what jobs each T-cell type does a. T-cells interact with antigen- presenting phagocytes during the immuneresponseb. T cells only recognize antigens on the surface of host cells that are “presented” on a protein complex the major histocompatibility complexc. T cell subtypesi. Tc cytotoxic cells- Kill host cells that have been infected by a virusii. TH1- releases cytokines that induce inflammationiii. TH2- Stimulate antigen reactive B cells to proliferate and produce antibodies 9. Briefly describe what a superantigen does a. Bacterial exotoxins that interact indirectly with host T helper cells and antigen-presenting cells b. Proteins produced by certain viral and bacterial pathogensi. Bind outside the MHC T cell receptors binding siteii. Result in activation of large numbers of T-cells and production of cytokines, producing excessive inflammation and tissue damage10. Be able to label the major parts of an antibody molecule a.11. Know what part binds to antigensa. Variable region 12. Be able to state what an epitope is a. T-cell receptors or antibodies do not recognize whole molecules, but smallregions of large molecules called epitopes, also called antigenic determinants13. Know how natural immunity is acquireda. After an infection, immunity to a pathogen develops 14. Be able to describe what artificial immunity is, and what active and passive artificial immunity is a. Artificial Immunity: immunity induced by artificial human intervention b. Artificial Active- Uses vaccination to produce response that provides immunityi. In some cases, additional subsequent booster vaccinations provide for longer immunity c. Artificial Passive- no response of the immune system is involved- individual receives antibodies i. Examplesii. Injection of antiserum (serum containing antibodies against the specific pathogen or toxin) into a person recently infected or exposed to a toxin (snake anti venom)iii. Newborns receive IgG antibodies across the placenta prior to birth- provide short term disease protection after birth15. Know about each of the 3 types of vaccines mentioneda. Toxoid- exotoxins that have been chemically inactivated by are still antigenic b. Inactivated pathogen- Pathogens (bacteria or viruses_ are killed by reaction with chemical compounds or heati. Example- salk polio vaccinec. Live attenuated pathogen- a mutated variant of a pathogen is used.i. Mutant cannot cause significant disease but will stimulate immune system to produce immunity 16. Be able to describe in very general terms how influenza vaccine is made a. Seed viruses from WHO/CDC and Eggs from farms or human cell culturesb. Propagation of virus in chick embryos or cell culturec. Inactivation and purification d. REPEATED FOR EACH VIRUSe. Add all the viruses togetherf. Test for potency and sterilityg. Packaging and
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