immunity defenses invertebrates vertebrates chapter 48 Animal defenses --

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1 defenses Animal defenses -- immunity chapter 48 invertebrates coelomocytes, amoebocytes, hemocytes sponges, cnidarians, etc. annelids basophilic amoebocytes, acidophilic granulocytes arthropod immune systems barrier defense phagocytic cells hemocytes antimicrobial compounds Toll receptors horseshoe crabs limulus amebocyte lysate thinking about immunity two main types innate immunity non-specific defenses adaptive immunity specific defenses vertebrates non-specific defenses against infection epithelial tissue physical and chemical barrier skin acidity washing action secretions antimicrobial proteins lysozyme Stevens-Johnson syndrome

2 nonspecific ingested microbes non-specific defenses granulocytes (polymorphonuclear leukocytes) phagocytic white blood cells TLR - Toll-like receptors neutrophils % of white cells Giardia lamblia hepatitis A eosinophils - 2-5% of white cells multicellular threats basophils 0.5% of leukocytes degranulate - initiate inflammation monocytes - 5% of white cells NK cells large granular lymphocytes (LGL)

3 inflammatory response -- triggered by damaged tissues damage occurs (bacteria enter) bleeding - platelets begin clotting process cells at the site release cytokines mast cells degranulate releasing histamines neutrophils phagocytize foreign material monocytes arrive and mature into macrophages interferons anti-viral proteins secreted by virus-infected cells. complement system anti-microbial peptides in blood tissue repair macrophage cytokines neutrophil mast cell histamines macrophage cytokines specific specific bone marrow specific defenses (immune system) internal Lymphocytes B-cells antigens T-cells development of self vs. non-self b-cells - bone marrow t-cells - thymus lymphoid stem cell thymus B-cell T-cell blood, lymph, and lymphoid tissues (lymph nodes, spleen, and others)

4 self recognition antigen receptors - each cell has a single type of receptor B-cells T-cells MHC molecules class I MHC molecules bind to cytotoxic T-cells class II MHC molecules bind to helper T-cells during development, exposed to both types antigen presentation MHC molecules present protein fragments at cell surface some are foreign, some are not b-cell t-cell adaptive immune response antibodies enhance phagocytosis neutralize toxins cell lysis humoral humoral immunity cell-mediated 1st exposure mainly effective against bacteria, stimulates gives rise to engulfed viruses, and toxins in body fluids. antigen presenting cell cell-mediated immunity mainly effective against infected cells and cancerous cells b-cell cytotoxic t-cell helper t-cell clonal selection enhances helper t-cells leads to 2nd exposure plasma cells antibodies b-cells t-cells active cytotoxic t-cells

5 adaptive immune response humoral primary immune response Immunity and health issues cell-mediated 1st exposure first exposure days clonal selection stimulates gives rise to engulfed active immunity passive immunity vaccination / immunization antigen presenting cell secondary immune response quicker, stronger response immunological b-cell cytotoxic t-cell helper t-cell helper t-cells 2nd exposure plasma cells b-cells t-cells active cytotoxic t-cells antibodies transplants ABO blood groups... A, or B, or AB, or O alleles: IA IB i A (IA IA or IAi) B (IB IB or IBi) AB (IA IB ) AB O (ii) RH factor... antigen on a transmembrane protein (probably an ion channel) organ transplantation anti-rejection drugs living-related, cadaveric MHC testing -Joseph Blow highly variable HLA profiles must be ABO match must be good HLA match they look at 3 MHC loci (best match is a 6)

6 allergies -- inappropriate reaction to an antigen (allergen) IgE antibodies bind to mast cells and basophils genetic and environmental component anaphylaxis or anaphylactic shock... urticaria IgE Histamine Allergen Granule Mast cell