Word Roots an- = without; -aphy = suck (anaphylactic shock: an acute, life-threatening, allergic response) anti- = against; -gen = produce (antigen: a foreign macromolecule that does not belong to the host organism and that elicits an immune response) macro- = large; -phage = eat (macrophage: an amoeboid cell that moves through tissue fibers, engulfing bacteria and dead cells by phagocytosis) mono- = one (monocyte: an agranular leukocyte that is able to migrate into tissues and transform into a macrophage) neutro- = neutral; -phil = loving (neutrophil: the most abundant type of leukocyte; neutrophils tend to self-destruct as they destroy foreign invaders, limiting their life span to but a few days) perfora- = bore through (perforin: a protein that forms pores in a target cell’s membrane) 3/25/2017

Immunity: body's ability to destroy pathogens or other foreign material and to prevent further cases of certain infectious diseases Go on to the Campbell Biology site, Chapter 24 activities, do them as we learn the work, and then take the activity quiz and submit it to me when we are done with the chapter. 3/25/2017

24.1 Nonspecific defenses against infection include the skin and mucous membranes, phagocytic cells, and antimicrobial proteins Read pp. 482-484 3/25/2017

Pathogen just waiting to enter body to produce disease Disease: change interfering w/normal body functioning Symptoms: changes produce in body Pathogens (disease-causing microorgan-isms: viruses, bacteria, fungi, protists) cause infectious diseases Infection: body invaded by pathogen Indirect contact with infected person Airborne-coughing, sneezing common cold, measles, mumps, influenza Direct contact with infected person Sexual contact Through contaminated food or water Food poisoning, handled by infected person Through bite of infected animal-vector Ticks, mosquitoes 3/25/2017

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Vocabulary Toxins: poisonous substances produced by microorganisms Transported by blood Cause serious and fatal effects Endemic: disease restricted to particular region (cholera/plague in parts of Asia) Epidemic Disease involving many more people than usual in particular community, or One that spreads into regions where it does not normally occur (influenza, SARS, AIDS) Pandemic: epidemic spreads throughout world 3/25/2017

recognizes specific invaders/attacks/eliminates them do not distinguish individual infectious agents-guards against all infections, regardless of cause recognizes specific invaders/attacks/eliminates them First line of defense (can’t cause disease if kept out) (gets through skin/mucus/etc.) 3/25/2017

1st line of defense keep things out that cause diseases Skin:  Tough, physical, unbroken barrier that blocks pathogens from entering body Glandular secretions (sweat, saliva, tears) give chemical defenses (acidic pH, lysozyme) that inhibit or kill microbes Mucus membranes Mucus traps microbes Cilia Filters air Mucous propelled to throat, then swallowed Stomach HCl/digestive enzymes Kill swallowed bacteria 3/25/2017

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2nd line of defense WBCs leave blood to find invading cells in interstitial fluid/body tissues Phagocytes Engulf microbes Neutrophils/Monocytes Phagocytize bacteria/viruses Macrophages Develop from monocytes Natural killer cells Attack cancer cells/virus-infected cells Cause cytolysis 3/25/2017

Interferon Antimicrobial protein produced by virus-infected cells Can’t save invaded cells Helps healthy cells resist viruses Interferes with viral replication Slows down progress of infection Give specific defenses time to respond Interferon 3/25/2017

Inactive antimicrobial proteins circulate in blood Complement proteins Inactive antimicrobial proteins circulate in blood Activated by immune system or by microbes Action Coat microbe surfaces/easier for macrophages to engulf Cut lethal holes in microbial membranes Amplify inflammatory response 3/25/2017

24.2 The inflammatory response mobilizes nonspecific defense forces (2nd line of defense) Read pg. 485 3/25/2017

Histamine causes sneezing, coughing, redness, itching, runny eyes/nose Vasodilation: area becomes hot, red, swollen due to increased blood supply Swelling against nerves causes pain Accumulation of fluid dilutes toxins present 3/25/2017

Systemic action of response, due to microbes or their toxins circulating in blood Produces more WBCs Cause fever Stimulate phagocytosis/inhibit microbe growth Chemicals released stimulate WBC actions Microbes survive within narrow temperature range Can often slow down/stop growth of some >39oC/103o-dangerous >41oC/105o-often fatal 3/25/2017

24.3 The lymphatic system becomes a crucial battleground during infection 24.4 The immune response counters specific invaders 24.5 Lymphocytes mount a dual defense 24.6 Antigens have specific regions where antibodies bind to them Read pp. 486-489 3/25/2017

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Lymphatic system Open network of vessels, lymph nodes, associated glands Functions Return excess fluid from interstitial fluid to circulatory system Fight infection Filters pathogens from blood Contain WBCs that respond to trapped pathogens 3/25/2017

Lymph fluid of lymphatic system Lymph nodes Activated during infection (swell, tender, aches, pain) Lymph Enters through open, lymphatic capillaries Largest lymph ducts empty into circulatory system veins in shoulders Similar to interstitial fluid (less oxygen, fewer nutrients) Microbes from infected sites/cancer cells phagocytized by macrophages Lymphocytes activated/mount specific immune response 3/25/2017

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Specific defenses Immune system (immunity) 3rd line of defense Extreme specificity, memory, response on 2nd exposure Amplifies inflammatory & complement responses Self vs. nonself Antigen Any molecule (polysaccharide/protein) eliciting immune response Pathogen or part, mold, bacterial toxin, insect venom, pollen, viruses Produce antibodies Attaches to antigen Antigen remembered and reacted to in future 3/25/2017

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Immunity: resistance to specific invaders growth of B and T cells in response to infection long lasting long lasting Lasts as long as they remain in circulation, usually for several weeks 3/25/2017

Lymphocytes (WBCs in immune system arise from stem cells in bone marrow/accumulate in lymph/lymph nodes/spleen/blood) Humoral immunity Fight bacteria/ viruses in blood/ interstitial fluid Mounted by B cells that produce antibodies Transferred passively Cell-mediated immunity Fight bacteria/ viruses/ fungi/ protozoan/cancer inside cells Mounted by T cells that kill directly Not transferred passively 3/25/2017

Recognize/respond to specific antigen B/T cells must mature Recognize/respond to specific antigen Cells have antigen receptors that bind antigens Humans have 100 million to 100 billion different kinds of B/T cells 3/25/2017

24.7 Clonal selection musters defensive forces against specific antigens 24.8 The initial immune response results in a type of “memory” Read pp. 490-491 3/25/2017

Enter bloodstream, combines w/antigens & clump Plasma cells secrete up to 2000 antibody molecules/sec. during 4-5 day lifetime Enter bloodstream, combines w/antigens & clump Macrophages engulf & destroy clumped antigens http://bcs.whfreeman.com/thelifewire/content/chp18/1802004.html 3/25/2017

Immune response 1o immune response 2o immune response Effector cells produced Delay between exposure to antigen and secretion of antibodies Release of modest levels of antibodies 2o immune response Exposed to same antigen Faster response Lasts longer Higher antibody levels 3/25/2017

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24. 9 B cells are the main warriors of humoral immunity 24 24.9 B cells are the main warriors of humoral immunity 24.10 Antibodies are the weapons of humoral immunity 24.11 Antibodies mark antigens for elimination 24.12 Monoclonal antibodies are powerful tools in the lab and clinic Read pp. 492-495 3/25/2017

B cells produce Antibodies Protein in blood plasma Attaches to one kind of antigen Antigen-binding (determinant) site is antigen specific May have several antigenic determinants 5 major classes of human antibodies based on nature of C region (immunoglobulins-IgG, IgA, IgD, IgE, IgM) 3/25/2017

All mechanisms involve specific recognition phase (antibodies of humoral immunity) followed by nonspecific destruction phase (phagocytosis/complement proteins) 3/25/2017

Monoclonal antibodies Medical diagnoses (pregnancy tests-test for presence of specific hormone, HCG) Target drugs to cells that cause disease (cancer) 3/25/2017

Read pp. 496-498 Activity 24A (1st of 2) 24.13 T cells mount the cell-mediated defense and aid humoral immunity 24.14 Cytotoxic T cells may help prevent cancer 24.15 The immune system depends on our molecular fingerprints Read pp. 496-498 Activity 24A (1st of 2) 3/25/2017

T cells immune response http://bcs.whfreeman.com/thelifewire/content/chp18/1802003.html T cells immune response Circulate in blood/lymph Attack infected body cells Promote phagocytosis by other WBCs Stimulate humoral response (B cells produce antibodies) Rejection by T cells 3/25/2017

Helper T-cells recognize self protein/foreign antigen presented by APC T cells activated by binding to self-nonself complex 3/25/2017

Activate cytotoxic T cells and macrophages Helper T cells: Activate cytotoxic T cells and macrophages Stimulate release of antibodies by B cells Interact w/antigen-presenting cells (APCs) getting macrophages involved 3/25/2017

apoptosis (programmed cell death) and lysis (cancer) apoptosis (programmed cell death) and lysis 3/25/2017

Antigens are proteins specific to each particular microorganism Antigens are proteins specific to each particular microorganism. They act as identity card that allows immune system to recognize invader organisms. 3/25/2017

Eventually, # infectious agents decreases Eventually, # infectious agents decreases. Need to inactivate cells and put them to rest, or they’d continue to fight own cells. T-suppressor cell (or T8) sends out messages to other cells and "de-activate" them. Activated B-cell produce millions of antibodies, a protein that binds with antigen. 3/25/2017

http://bcs.whfreeman.com/thelifewire/content/chp18/1802001.html 3/25/2017

Recognition of self over nonself Proteins on cell surface specific to each person Lymphocytes recognize Class I proteins on all nucleated body cells Class II proteins found only on B cells, activated T cells, macrophages Determined by 6 loci, each w/100s alleles Only identical twins can have identical set of self proteins Coded for by MHC (major histocompatibility complex) genes 3/25/2017

Different self proteins recognized as foreign Transplant problems Different self proteins recognized as foreign Caused by T cell immune response Risk of rejection minimized by Donor’s self proteins match recipient’s as closely as possible Immune suppression drugs Interfere with immune system Cyclosporine suppresses only cell-mediated response 3/25/2017

Read pp. 498-500 Activity 24B (last one) 24.16 Malfunction or failure of the immune system causes diseases 24.17 Allergies are overreactions to certain environmental antigens 24.18 AIDS leaves the body defenseless Read pp. 498-500 Activity 24B (last one) 3/25/2017

Immune disorders overreaction to antigens Physical/emotional stress weakens immune system Autoimmune diseases: immune system turns against body’s own molecules Rheumatoid arthritis: antibody-mediated damage to joints, bones, and cartilage Multiple sclerosis: T cells attack myelin Crohns: attacks digestive system Insulin-dependent diabetes: insulin-producing cells are subjected to cell-mediated response Lupus: production of antibodies against molecules such as histones and DNA 3/25/2017

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Allergies: overreactions to environment allergens Antihistamines interfere w/histamine action and give temporary relief 1st exposure (pollen/dust/insect toxins/cat saliva/ proteins) Mast cells found thruout body/especially in nasal lining Histamines increase flow of blood/fluids, (sneezing, runny eyes/nose) 2nd exposure Histamine in greater amounts Allergy symptoms (nasal irritation, itchiness, tears ) 3/25/2017

Asthma Anaphylactic shock Serious allergic reactions Smooth muscles contract around bronchioles Anaphylactic shock Mast cells release large amount of histamine (inflammatory)/dilates blood vessels suddenly Sudden drop in blood pressure (shock) Potentially fatal Extreme allergy to certain allergens 3/25/2017

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Immunodeficiency diseases Lack component(s) of immune system Susceptible to infections that would ordinarily not cause problem (opportunistic infection) SCID (severe combined immunodeficiency)- inherited disorder, T/B cells absent or inactive Hodgkin’s disease: cancer of lymphocytes; treatment can suppress immune system HIV leads to AIDS Attacks helper T cells Eliminates humoral/cell-mediated immunity 3/25/2017

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