Immunology EXAM 4 STUDY GUIDE o First line of defense non specific resistance Intact skin Mucous membranes and their secretions Normal microbial Tears o Second line of defense non specific resistance Phagocytes such as neutrophils eosinophils dendritic cells and macrophages Phagocytes o Neutrophils and macrophages are two major phagocytic cells in the body Inflammation Fever Antimicrobial substances Interferon s If you have a cut a fever will help repair it If fever gets too high it can kill you o Protect uninfected host cells from viral infection o Host must have virus for create interferons o Third line of defense Specific Specialized lymphocytes T cells B cells Antibodies Interferon s produced after infection Non specific Resistance immunity Inflammation A Tissue damage 1 Knife cuts into the skin 2 Chemicals i e histamine kinins cytokines are released by the damaged cells 3 Blood clot forms 4 Abscess starts to form 1 Call in white blood cells B Vasodilation and increased permeability of blood vessels i Phagocytes stick to endothelium ii Phagocytes squeeze between endothelial cells iii Phagocytosis of invading bacteria occurs C Phagocyte migration and phagocytosis 1 Neutrophil and macrophage destroy bacteria D Tissue repair 1 Scab and blood clot Phagocytosis o GOAL OF EVERYTHING IN IMMUNOLOGY o Is the ingestion of a microorganism or other substance by a cell The phases of phagocytosis o Two major phagocytic cells Neutrophil and microphages o Ingest and devour the foreign materials 1 Chemoaxis and Adherence of phagocyte to microbe 2 Ingestion of microbe by phagocyte 3 Formation of phagosome microbe is surrounded by the membrane 4 Fusion of phagosome with a lysosome This forms a PHAGOLYSOSOME 5 Digestion of ingested microbes by enzymes in the phagolysosome invader will be partially digested has been killed 6 Formation of residual body containing indigestible material 7 Discharge of waste materials Waste materials are important for our immune system Enzymes in lysosome are not in granule form and are NOT active inactive Degranualization when granules come into contact with foreign material they activate Waste material is important extracellular antigens Mechanism of Killing o H2O2 Cytoplasm Myeloperoxidase lysosome Cl ClO hypoclorite o Hypochlorite is the active ingredient in bleach Chronic Granulomatous Disease o Genetic Disorder Inability of phagocyte to make H2O2 Repeated bacterial infections Disease where it cannot make hydrogen peroxide Very serious many don t live past their teens Not very common Mycobacterium tuberculosis lives in the phagocytic cell o TB tuberculosis takes a long time to cure because it lives in a phagocytic cell o Leprosy TB s cousin because they re in the same genus o Not digested o Members of mycobacterium are acid fast Have an extra coating on their cell wall that makes them Fever impervious to things o Intensifies the effects of interferons inhibits growth of some microbes and speeds up body reactions that aid repair Increases activity of interferons Very positive part of our immune system resistance Repairs tissue damage speeds it up Fever is a good thing until it reaches 104 F Can die if it gets too high Inhibits some microorganisms o Three things that will cause fever Endotoxin Part of gram negative cell wall Gram negative bacteria A virus some Certain toxins How You Get Fever works the same for a virus or toxin pg 440 1 Macrophage ingest a gram negative bacterium 2 Bacterium in a vacuole releasing endotoxins that induce the macrophage to produce cytokines Interleukin 1 3 Cytokines are released into the blood stream by macrophages through which they travel into the hypothalamus 4 Cytokines induce hypothalamus to produce prostaglandins which reset the body temperature producing a fever Positive fever benefits come from this Interleukin 1 IL1 is a group of 11 cytokines which plays a central role in the regulation of immune and inflammatory responses to infections or sterile insults Chills o Kinetic energy to warm body up i e fight the cold causing a fever sweat cools body down to lower the temperature fever has broken o Increase body s temperature Specific Immunity Third Line of Defense o Specific immunity Resistance to a specific invader Body reacts against non self something that isn t you but not to self o Two Branches of Immunity Humoral Immunity antibodies Cellular cell mediated immunity Stronger part o Protects us from cancer o Autoimmunity Body reacts against itself o Specific Immunity Antigen Foreign material that induces immune response Antigen Properties Foreign to host not part of self Reasonably large molecule o 10 000MW molecular weight o Average amino acid 100MW Usually protein or polysaccharides or both Cyanide CN Deadliest of poisons Very small Not an antigen because of its size Can we ever have a vaccine for cyanide No because it is too small o Specific Immunity Antibodies Protein molecules synthesized in response to the presence of antigen which once formed combine with the antigen Typically called immunoglobins Ig Antibodies are ALWAYS proteins Antigens are USUALLY proteins An antibody is a protein produced by a host to bind to and thus inactivate foreign particles The particle is called the antigen It is frequently but not always a protein The binding of antibody to antigen is very specific so that if all goes well the antibody binds to that specific antigen only The part of the antigen molecule to which the antibody binds is called the epitope o Humoral Immunity Epitope square triangle circle Also called antigenic determinant A specific region won the surface of an antigen against which antibodies are formed Foreign bacterial cell Bacterial cell is antigen or made up of antigens Epitopes are not antigens they are too small They are however antigen determinants on antigens Once a specific antibody has bound to a specific epitope it cannot bind to any other epitope Example antibody A binds to epitope at its binding site Antibody A is now specific for epitope Antibody typically look like a Y shape There are antigen binding sites on the Y of antibody A group of serum proteins involved in phagocytosis and lysis of bacteria o Complement fixation the process in which complement combines with an antigen antibody complex 1st to the scene o 5 Types of Antibodies IgG Most common in the serum o Part of the blood Fixes complement Passes placenta IgM Fixes complement o Complement IgA IgD IgE Secretory Found in secretions o Tears saliva