* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download AP Biology
Survey
Document related concepts
Vectors in gene therapy wikipedia , lookup
Embryonic stem cell wikipedia , lookup
Human embryogenesis wikipedia , lookup
Cell culture wikipedia , lookup
Cellular differentiation wikipedia , lookup
Artificial cell wikipedia , lookup
Microbial cooperation wikipedia , lookup
Cell (biology) wikipedia , lookup
Organ-on-a-chip wikipedia , lookup
Neuronal lineage marker wikipedia , lookup
State switching wikipedia , lookup
Monoclonal antibody wikipedia , lookup
Adoptive cell transfer wikipedia , lookup
Cell theory wikipedia , lookup
Transcript
Fighting the Enemy Within! phagocytic leukocyte Immune / Lymphatic System AP Biology lymphocytes attacking cancer cell lymph system 2007-2008 Start and review with the masteringbiology.com Immunology video Another good one from McGraw-Hill Immune system game by NobelPrize.org AP Biology Avenues of attack Points of entry digestive system respiratory system urogenital tract break in skin Routes of attack circulatory system lymph system AP Biology Why an immune system? Attack from outside lots of organisms want you for lunch! animals are a tasty nutrient- & vitamin-packed meal cells are packages of macromolecules animals must defend themselves against invaders (pathogens) viruses HIV, flu, cold, measles, chicken pox bacteria pneumonia, meningitis, tuberculosis Lyme disease fungi yeast (“Athlete’s foot”…) protists amoeba, malaria Attack from inside AP Biology cancers = abnormal body cells Mmmmm, What’s in your lunchbox? Lines of defense 1st line: Non-specific barriers broad, external defense “walls & moats” skin & mucous membranes 2nd line: Non-specific patrols broad, internal defense “patrolling soldiers” leukocytes = phagocytic WBC 3rd line: True immune system specific, acquired immunity “elite trained units” lymphocytes & antibodies B cells & T cells AP Biology Bacteria & insects inherit resistance. Vertebrates acquire immunity. Figure 43.2 Pathogens (such as bacteria, fungi, and viruses) INNATE IMMUNITY (all animals) • Recognition of traits shared by broad ranges of pathogens, using a small set of receptors • Rapid response ADAPTIVE IMMUNITY (vertebrates only) • Recognition of traits specific to particular pathogens, using a vast array of receptors • Slower response AP Biology 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. Cell-mediated response: Cytotoxic cells defend against infection in body cells. Development of the key players, Red & White blood cells inflammatory response Red blood cells fight parasites Leukocytes Lymphocytes AP Biology develop into macrophages short-lived phagocytes 60-70% WBC Figure 43.7 Blood capillary Interstitial fluid Adenoid Tonsils Lymphatic vessels Thymus Tissue cells Peyer’s patches (small intestine) Appendix (cecum) Spleen Lymphatic vessel Lymph nodes Lymph node AP Biology Lymphatic vessel Masses of defensive cells 1st line: Non-specific External defense Barrier skin Lining of trachea: ciliated cells & mucus secreting cells Traps mucous membranes, cilia, hair, earwax Elimination coughing, sneezing, urination, diarrhea Unfavorable pH stomach acid, sweat, saliva, urine Lysozyme enzyme digests bacterial cell walls tears, sweat AP Biology 2nd line: Non-specific patrolling cells bacteria Patrolling cells & proteins attack pathogens, but don’t “remember” for next time leukocytes phagocytic white blood cells macrophages, neutrophils, natural killer cells macrophage complement system Free-floating proteins that destroy cells inflammatory response AP Biology increase in body temp. increase capillary permeability attract macrophages yeast Leukocytes: Phagocytic WBCs Attracted by chemical signals released by damaged cells Neutrophils most abundant WBC (~70%) ~ 3 day lifespan phagocyte Macrophages “big eater” phagocyte long-lived Natural Killer Cells AP Biology destroy virus-infected cells & cancer cells Destroying cells gone bad! Natural Killer Cells perforate cells release perforin protein insert into membrane of target cell forms pore allowing fluid to flow in & out of cell natural killer cell cell ruptures (lysis) apoptosis vesicle perforin cell membrane AP Biology perforin punctures cell membrane cell membrane virus-infected cell Anti-microbial proteins Complement system ~20 proteins circulating in blood plasma attack bacterial & fungal cells form a membrane attack complex perforate target cell extracellular fluid apoptosis cell lysis complement proteins form cellular lesion plasma membrane of invading microbe AP Biology complement proteins bacterial cell Inflammatory response Damage to tissue triggers local non-specific inflammatory response release chemical signals histamines & prostaglandins capillaries dilate, become more permeable (leaky) delivers macrophages, RBCs, platelets, clotting factors fight pathogens clot formation increases temperature decrease bacterial growth stimulates phagocytosis speeds up repair of tissues AP Biology Figure 43.8-1 Pathogen Mast cell Splinter Macrophage Signaling molecules Capillary Neutrophil Red blood cells AP Biology Figure 43.8-2 Pathogen Mast cell Splinter Macrophage Signaling molecules Capillary Neutrophil Red blood cells AP Biology Movement of fluid Figure 43.8-3 Pathogen Mast cell Splinter Macrophage Signaling molecules Capillary Neutrophil Red blood cells AP Biology Movement of fluid Phagocytosis Fever When a local response is not enough system-wide response to infection activated macrophages release interleukin-1 triggers hypothalamus in brain to readjust body thermostat to raise body temperature higher temperature helps defense inhibits bacterial growth stimulates phagocytosis speeds up repair of tissues causes liver & spleen to store iron, reducing blood iron levels bacteria need large amounts AP Biology of iron to grow 3rd line: Acquired (active) Immunity Specific defense with memory B cell lymphocytes B cells antibodies (a.k.a. immunoglobulins) T cells Responds to… antigens cellular name tags specific pathogens specific toxins abnormal body cells (cancer) AP Biology How are invaders recognized? Antigens cellular name tag proteins “self” antigens no response from WBCs “foreign” antigens response from WBCs pathogens: viruses, bacteria, protozoa, parasitic worms, fungi, toxins non-pathogens: cancer cells, transplanted tissue, pollen “self” AP Biology “foreign” bone marrow Lymphocytes B cells mature in bone marrow humoral response system “humors” = body fluids attack pathogens still circulating in blood & lymph produce antibodies mature in thymus cellular response system T cells attack invaded cells “Maturation” learn to distinguish “self” from “non-self” antigens if react to “self” antigens, cells AP Biology are destroyed during maturation Figure 43.20 Humoral (antibody-mediated) immune response Cell-mediated immune response Key Antigen (1st exposure) Engulfed by Antigenpresenting cell Stimulates Gives rise to B cell Helper T cell Cytotoxic T cell Memory helper T cells Antigen (2nd exposure) Plasma cells Memory B cells Memory cytotoxic T cells Active cytotoxic T cells Secreted antibodies Defend against extracellular pathogens AP Biology Defend against intracellular pathogens and cancer B cells Attack, learn & remember pathogens circulating in blood & lymph Produce specific antibodies against specific antigen Types of B cells plasma cells immediate production of antibodies rapid response, short term release memory cells continued circulation in body long term immunity AP Biology 10 to 17 days for full response Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y release antibodies Y Y plasma cells AP Biology recognition Y Y Y Y Y Y Y Y macrophage Y Y Y Y Y captured invaders Y memory cells Y B cells + antibodies Y Y Y Y Y tested by B cells (in blood & lymph) invader (foreign antigen) “reserves” Y Y B cell immune response clones 1000s of clone cells Y Y multi-chain proteins binding region matches molecular shape of antigens each antibody is unique & specific Y Y foreign antigens tagging “handcuffs” “this is foreign…gotcha!” Y Y millions of antibodies respond to millions of Y Y Y Y Y Y Y Proteins that bind to a specific antigen Y Y Antibodies Y Y Y antigenbinding site on antibody antigen Y Y Y Y variable binding region AP Biology each B cell has ~50,000 antibodies Y Y Y Structure of antibodies Y s s s light chain B cell membrane AP Biology s s s s s s s s s s s s s s s s s s s s s s Y s Y s s s Y s s Y s variable region s Y s s Y s Y Y antigen-binding site light chain heavy chains light chains antigen-binding site heavy chains antigen-binding site What do antibodies do to invaders? neutralize invading pathogens tagged with antibodies macrophage eating tagged invaders AP Biology Y capture precipitate apoptosis Immunoglobulins IgM 1st immune response activate complement proteins Antibody levels Classes of antibodies invading Exposure pathogens to tagged with antigen antibodies IgM IgG Y 0 macrophage eating tagged invaders 2 4 Weeks IgG 2nd response, major antibody circulating in plasma promote phagocytosis by macrophages IgA in external secretions, sweat & mother’s milk IgE promote release of histamine & lots of bodily fluids evolved as reaction to parasites triggers allergic reaction AP Biology IgD receptors of B cells??? 6 Figure 43.UN02 Stem cell Cell division and gene rearrangement Elimination of self-reactive B cells Antigen Clonal selection Formation of activated cell populations Memory B cells Antibody Plasma cells Pathogen AP Biology Receptors bind to antigens Vaccinations Immune system exposed to harmless version of pathogen stimulates B cell system to produce antibodies to pathogen “active immunity” rapid response on future exposure creates immunity without getting disease! Most successful against viruses AP Biology 1914 – 1995 Jonas Salk April 12, 1955 Developed first vaccine against polio attacks motor neurons Albert Sabin 1962 oral vaccine AP Biology Passive immunity Obtaining antibodies from another individual maternal immunity antibodies pass from mother to baby across placenta or in mother’s milk critical role of breastfeeding in infant health mother is creating antibodies against pathogens baby is being exposed to Injection injection of antibodies short-term immunity AP Biology What if the attacker gets past the B cells in the blood & actually infects (hides in) some of your cells? You need trained assassins to recognize & kill off these infected cells! Attack of the Killer T cells! T AP Biology But how do T cells know someone is hiding in there? 2007-2008 How is any cell tagged with antigens? Major histocompatibility (MHC) proteins proteins which constantly carry bits of cellular material from the cytosol to the cell surface “snapshot” of what is going on inside cell give the surface of cells a unique label or “fingerprint” MHC protein Who goes there? self or foreign? T or B cell MHC proteins displaying self-antigens AP Biology Figure 43.11 Antigenbinding site T cell antigen receptor V V Variable regions C C Constant regions Disulfide bridge chain T cell AP Biology Transmembrane region chain Plasma membrane Cytoplasm of T cell How do T cells know a cell is infected? Infected cells digest some pathogens MHC proteins carry pieces to cell surface foreign antigens now on cell membrane called Antigen Presenting Cell (APC) macrophages can also serve as APC tested by Helper T cells infected cell WANTED MHC proteins displaying foreign antigens TH cell T cell with antigen receptors AP Biology T cells Attack, learn & remember pathogens hiding in infected cells recognize antigen fragments also defend against “non-self” body cells cancer & transplant cells Types of T cells helper T cells alerts rest of immune system killer (cytotoxic) T cells attack infected body cells memory T cells long term immunity AP Biology T cell attacking cancer cell Figure 43.12 Displayed antigen fragment T cell T cell antigen receptor MHC molecule Antigen fragment Pathogen Host cell (a) Antigen recognition by a T cell Top view Antigen fragment MHC molecule Host cell AP Biology (b) A closer look at antigen presentation Animation: Role of B Cells AP Biology © 2011 Pearson Education, Inc. Right-click slide / select “Play” Attack of the Killer T cells Destroys infected body cells binds to target cell secretes perforin protein punctures cell membrane of infected cell apoptosis vesicle Killer T cell Killer T cell binds to infected cell infected cell AP Biologydestroyed cell membrane perforin punctures cell membrane target cell cell membrane Immune system & Blood type blood type antigen on RBC antibodies in blood donation status A type A antigens on surface of RBC anti-B antibodies __ B type B antigens on surface of RBC anti-A antibodies __ AB both type A & type B antigens on surface of RBC no antibodies universal recipient O no antigens on surface of RBC anti-A & anti-B antibodies universal donor Matching compatible blood groups is critical for blood transfusions A person AP Biologyproduces antibodies against foreign blood antigens Animation: Helper T Cells Right-click slide / select “Play” © 2011 Pearson Education, Inc. Animation: Cytotoxic T Cells AP Biology © 2011 Pearson Education, Inc. Right-click slide / select “Play” Figure 43.16 Antigenpresenting cell Antigen fragment Pathogen Class II MHC molecule Accessory protein Antigen receptor 1 Helper T cell Cytokines Humoral immunity B cell AP Biology 3 2 Cytotoxic T cell Cellmediated immunity Figure 43.17-1 Cytotoxic T cell Accessory protein Class I MHC molecule Infected cell 1 AP Biology Antigen receptor Antigen fragment Figure 43.17-2 Cytotoxic T cell Accessory protein Class I MHC molecule Infected cell 1 AP Biology Antigen receptor Perforin Pore Antigen fragment 2 Granzymes Figure 43.17-3 Cytotoxic T cell Accessory protein Class I MHC molecule Infected cell 1 AP Biology Released cytotoxic T cell Antigen receptor Perforin Pore Antigen fragment 2 Dying infected cell Granzymes 3 Immune system malfunctions Auto-immune diseases immune system attacks own molecules & cells lupus antibodies against many molecules released by normal breakdown of cells rheumatoid arthritis antibodies causing damage to cartilage & bone HIV Helper T cells attacked by virus multiple sclerosis T cells attack myelin sheath of brain & spinal cord nerves Allergies over-reaction to environmental antigens allergens = proteins on pollen, dust mites, in animal AP Biology saliva stimulates release of histamine Figure 43.22 Histamine IgE Allergen Granule Mast cell AP Biology Figure 43.23 AP Biology HIV & AIDS Human Immunodeficiency Virus virus infects helper T cells helper T cells don’t activate rest of immune system: killer T cells & B cells also destroys helper T cells AIDS: Acquired ImmunoDeficiency Syndrome infections by opportunistic diseases death usually from “opportunistic” infections pneumonia, cancers AP Biology HIV infected T cell Animation: HIV Reproductive Cycle Right-click slide / select “Play” AP Biology © 2011 Pearson Education, Inc. Helper T cell concentration (in blood (cells/mm3) Figure 43.25 Latency AIDS Relative anti-HIV antibody concentration 800 Relative HIV concentration 600 Helper T cell concentration 400 200 0 0 AP Biology 1 3 7 8 2 4 5 6 Years after untreated infection 9 10 Review Videos Bioflix: Immune response Bozeman Biology: Plant and Animal Defense video AP Biology