© 2014 Pearson Education, Inc. 35 Immunity

© 2014 Pearson Education, Inc. Recognition and Response ________________________________________, _______________________________________

© 2014 Pearson Education, Inc. Figure 35.1

© 2014 Pearson Education, Inc. ________________________________________ ______________________________________ Innate Immunity

© 2014 Pearson Education, Inc. ________________________________________ ______________________________________ _______________________________________ Adaptive Immunity

© 2014 Pearson Education, Inc. Figure 35.2 INNATE IMMUNITY (all animals) Recognition of traits shared by broad ranges of pathogens, using a small set of receptors Rapid response Barrier defenses: Skin Mucous membranes Secretions Internal defenses: Phagocytic cells Natural killer cells Antimicrobial proteins Inflammatory response Humoral response: Antibodies defend against infection in body fluids. Cytotoxic cells defend against infection in body cells. Cell-mediated response: ADAPTIVE IMMUNITY (vertebrates only) Recognition of traits specific to particular pathogens, using a vast array of receptors Slower response Pathogens (such as bacteria, fungi, and viruses)

© 2014 Pearson Education, Inc. Figure 35.3 Pathogen Vacuole PHAGOCYTIC CELL Lysosome containing enzymes Pseudopodia surround pathogens. engulfed by endocytosis. Pathogens Vacuole forms. Vacuole and lysosome fuse. Pathogens destroyed. Debris from pathogens released

© 2014 Pearson Education, Inc. Cellular Innate Defenses _______________________________________ –_______________________________________

© 2014 Pearson Education, Inc. ________________________________________ ______________________________________

© 2014 Pearson Education, Inc. Antimicrobial Peptides and Proteins ________________________________________ ______________________________________ ________________________________________

© 2014 Pearson Education, Inc. Inflammatory Response ________________________________________ ______________________________________

© 2014 Pearson Education, Inc. Figure Pathogen Splinter Macro- phage Capillary Neutrophil Red blood cells Mast cell Signaling molecules 1 Histamines and cytokines released. Capillaries dilate.

© 2014 Pearson Education, Inc. Figure Pathogen Splinter Macro- phage Capillary Neutrophil Red blood cells Mast cell Signaling molecules 1 Histamines and cytokines released. Capillaries dilate. Movement of fluid Antimicrobial peptides enter tissue. Neutrophils are recruited. 2

© 2014 Pearson Education, Inc. Figure Pathogen Splinter Macro- phage Capillary Neutrophil Red blood cells Mast cell Signaling molecules 1 Histamines and cytokines released. Capillaries dilate. Movement of fluid 2 Antimicrobial peptides enter tissue. Neutrophils are recruited. Phagocytosis 3 Neutrophils digest pathogens and cell debris. Tissue heals.

© 2014 Pearson Education, Inc. adaptive immunity, pathogen-specific recognition ________________________________________ ______________________________________, ______________________________________ ________________________________________ ____________________________________

© 2014 Pearson Education, Inc. Figure 35.UN01 Antigen receptors Mature B cellMature T cell

© 2014 Pearson Education, Inc. Figure 35.6 Antigen- binding site B cell antigen receptor Disulfide bridge Light chain Antigen- binding site Variable regions Constant regions Transmembrane regions Plasma membrane Heavy chains Cytoplasm of B cell B cell V V C C C C V V

© 2014 Pearson Education, Inc. _________________________________________ _________________________________________ _________________________________________ _________________________________________

© 2014 Pearson Education, Inc. Figure 35.7 Antigen- receptor Antibody B cell Antigen Epitope Pathogen (a) B cell antigen receptors and antibodies Antibody C Antibody A Antibody B Antigen (b) Antigen receptor specificity

© 2014 Pearson Education, Inc. Figure 35.8 Antigen- binding site T cell antigen receptor Disulfide bridge T cell Cytoplasm of T cell  chain  chain Variable regions Constant regions Transmembrane region Plasma membrane VV CC

© 2014 Pearson Education, Inc. _________________________________________ _________________________________________ _________________________________________ _________________________________________

© 2014 Pearson Education, Inc. _________________________________________

© 2014 Pearson Education, Inc. Figure 35.9 Host cell Displayed antigen fragment MHC molecule Antigen fragment Pathogen T cell T cell antigen receptor

© 2014 Pearson Education, Inc. B and T Cell Diversity _________________________________________

© 2014 Pearson Education, Inc. Figure pre-mRNA mRNA DNA of differentiated B cell DNA of undifferentiated B cell RNA processing Transcription of permanently rearranged, functional gene Recombination deletes DNA between randomly selected V segment and J segment Functional gene Translation Light-chain polypeptide Variable region Constant region B cell Antigen receptor V C C Cap V 39 J5J5 Poly-A tail V V V V C CC C C V 39 J5J5 Intron C V 39 J5J5 Intron V 38 V 37 V 39 V 38 V 40 V 37 J5J5 J4J4 J3J3 J2J2 J1J1 Intron C

© 2014 Pearson Education, Inc. Figure 35.10a DNA of undifferentiated B cell V 39 V 38 V 40 V 37 J5J5 J4J4 J3J3 J2J2 J1J1 Intron DNA of differentiated B cell pre-mRNA Transcription of permanently rearranged, functional gene Recombination deletes DNA between randomly selected V segment and J segment Functional gene C V 39 V 38 V 37 J5J5 Intron C C V 39 J5J5 21

© 2014 Pearson Education, Inc. Figure 35.10b pre-mRNA Intron C V 39 J5J5 mRNA RNA processing C Cap V 39 J5J5 Poly-A tail Translation Light-chain polypeptide Variable region Constant region B cell Antigen receptor V C V V V V C C C C 43

© 2014 Pearson Education, Inc. Self-Tolerance _________________________________________

© 2014 Pearson Education, Inc. _________________________________________ _________________________ –____________________________________________ ____________________________________________

© 2014 Pearson Education, Inc. Figure B cells that differ in antigen specificity Antigen Antigen receptor Antibody Plasma cellsMemory cells

© 2014 Pearson Education, Inc. _________________________________________ __________________________________________ ________________________________________ Immunological memory can span many decades Immunological Memory

© 2014 Pearson Education, Inc. Figure Primary immune response to antigen A Secondary immune response to antigen A Antibodies to A Antibodies to B Primary immune response to antigen B Antibody concentration (arbitrary units) Exposure to antigen A Exposure to antigens A and B Time (days) 10 2

© 2014 Pearson Education, Inc. Adaptive immunity _________________________________________ _________________________________________ _________________________________________ _________________________________________

© 2014 Pearson Education, Inc. Cytotoxic T Cells: ________________________________________

© 2014 Pearson Education, Inc. Figure Antigen fragment Class I MHC molecule Accessory protein Antigen receptor Cytotoxic T cell Infected cell 1

© 2014 Pearson Education, Inc. Figure Antigen fragment Class I MHC molecule Accessory protein Antigen receptor Cytotoxic T cell Infected cell 1 Pore 2 Perforin Granzymes

© 2014 Pearson Education, Inc. Figure Antigen fragment Class I MHC molecule Accessory protein Antigen receptor Cytotoxic T cell Infected cell 1 Pore 2 Perforin Granzymes Released cytotoxic T cell Dying infected cell 3

© 2014 Pearson Education, Inc. B Cells and Antibodies: A Response to Extracellular Pathogens ________________________________________

© 2014 Pearson Education, Inc. Figure Helper T cell Antigen fragments Pathogen CD4 Antigen- presenting cell Antigen receptor 1 MHC

© 2014 Pearson Education, Inc. Figure Helper T cell Antigen fragments Pathogen CD4 Antigen- presenting cell Antigen receptor MHC B cell Cytokines Activated helper T cell 2 1

© 2014 Pearson Education, Inc. Figure Helper T cell Antigen fragments Pathogen CD4 Antigen- presenting cell Antigen receptor MHC B cell Cytokines Activated helper T cell Plasma cells Secreted antibodies Memory B cells

© 2014 Pearson Education, Inc. ___________________... –…_________________________________________ –…_________________________________________.

© 2014 Pearson Education, Inc. Figure 35.16a B cell Helper T cell Antigen- presenting cell Engulfed by Antigen (1st exposure) Humoral (antibody-mediated) immune response Cell-mediated immune response Key Stimulates Gives rise to Cytotoxic T cell

© 2014 Pearson Education, Inc. Figure 35.16b B cell Helper T cell Humoral (antibody-mediated) immune response Cell-mediated immune response Cytotoxic T cell Key Stimulates Gives rise to Memory helper T cell Memory cytotoxic T cells Memory B cells Antigen (2nd exposure) Active cytotoxic T cells Defend against intracellular pathogens and cancer Defend against extracellular pathogens Plasma cells Secreted antibodies

© 2014 Pearson Education, Inc. Immunization ______________________________- –____________________________________ ___________________ – –____________________________________

© 2014 Pearson Education, Inc. Fig a, p.694Vaccines

© 2014 Pearson Education, Inc. Allergies _____________________________________

© 2014 Pearson Education, Inc. Fig a, p.694

© 2014 Pearson Education, Inc. Fig b, p.694