BIOL 244 1nd Edition Lecture 4Outline of Last Lecture I. CoagulationII. Blood Clot III. Blood GroupsIV. Rh Factor V. Lymphatic SystemVI. Lymphatic VesselsVII. Lymphoid CellsVIII. Lymphoid TissueIX. Lymph NodesOutline of Current Lecture I. Innate vs. Adaptive Immune System II. Humoral Immune ResponseIII. 2 Ways to Acquire Humoral Immunity IV. Antibodies in Humoral Immune Response V. Cell-mediated Immune Response Current LectureI. Innate vs. Adaptive Immune System a. Innate immune systemThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.i. Present from birth: provides protection from anything that might not belong in the body such as fungi, bacteria, etc.ii. Non-specific: does not fight against certain/specific kinds of foreign invaders1. Example: neutrophils just recognize bacteria as a wholeb. Adaptive immune system i. Incredibly specificii. Components are present in body at birth, but the cells can’t protect the body against invaders until it encounters them1. Example: Syphilis- the cells in the adaptive immune system won’t produce immune response against syphilis until they encounter syphilis onceiii. Immunocompetence1. Lymphocytes produce receptors for antigens very early in developmenta. Everyone has the ability to fight off syphilis2. If you’re never infected with syphilis, your body will never use the receptorsa. The receptor has the ability to recognize and bind to one specific antigen only, if it has never encountered the antigen it is considered naïve and immunocompetent 3. There are hundreds of thousands immunocompetent but naïve B cells in the bodya. Each have one receptor for a different antigenII. Humoral Immune Responsea. Antigen Challengei. An immunocompetent B-Cell meets the antigen that it has a receptor for1. Binding stimulates proliferation (division and creation of many copies) ii. Antigen enters body and comes in contact with receptor1. Keep in mind: the presence of receptor has nothing to do with antigen being in the body-it has always been thereb. Clonal selection of B cellsi. The group that is created through proliferation is called a cloneii. End up with an army of identical B cells, all which express the same receptors for the same antigen c. Differentiationi. Plasma cells (effector cells)1. Produce antibodies that are identical to the receptors present on the original cell’s surface 2. Secreted into body fluid 3. Fairly short lived ii. Memory cells 1. Do the bulk of work in protecting the body2. Some of the clone becomes the memory cells3. Saved for the future a. The immune system is ready to go next timeb. Can respond more quickly and more strongly the 2nd timec. This does not occur in innate immunity d. Primary vs. Secondary Immune Responsei. Primary immune response: the first time the body encounters a particularantigen1. Primary immune responses take 3-7 days to have detectable amount of antibodies in bloodii. Secondary response: the antigen binds on receptors to memory cells1. Causes them to proliferate and leads to differentiation of the clone III. 2 Ways to Acquire Humoral Immunitya. Actively: your own B cells are stimulated to produce antibodiesi. Naturally: Infected with somethingii. Artificially: Injected with an antigen1. Dead pathogensa. Heated at not too high of a temperature: pathogen is dead but antigens are still functioning2. Live pathogena. Attenuated pathogen: technically alive but damaged to the point of not causing severe case of disease b. Passively: have received antibodies from a donor (not coming from your own body) i. Naturally: Occurs during pregnancy (mothers antibodies to baby), lactation (antibodies in milk)1. Newborns who are nursing get most of their protecting from their mother’s immune system ii. Artificially: Injection of antibodies that were harvested from a donor1. People who have suffered through a disease and survived2. Infect horses so that they produce antibodies iii. Will isolate the antibody and purify it so that anyone can donate/receiveiv. This is a quick fix as no memory cells are formedIV. Antibodies in Humoral Immune Response a. Antibodies: type of plasma protein (IGs)i. Complex proteins, b. Simplest antibody is a T or Y shapec. 2 heavy chains and 2 light chains i. Heavy chains are longer than light chainsd. Constant (C) regioni. Constant region heavy chain: similar from one antibody to another ii. Determines what class a particular antibody belongs to1. Different classes of antibodies have different mechanisms for ridding the body of antigens2.e. Variable (V) regioni. Antigen binding siteii. Variable region produces specificity iii. “Variable region” because it differs from one antibody to anotherf. Each antibody has 2 antigen binding sights i. Heavy chain and light chain make up the antigen-bonding sightg. A single plasma cell is only capable of producing antibodies for one specific antigen h. How antibodies help to defend body against antigensi. Antibodies don’t directly destroy antigens1. Makes it easier for other components of the immune system to dothe destructive workii. Antibody must bind to an antigen1. Form an antigen-antibody complex.iii. Antibodies can cover the dangerous parts of an antigen 1. Neutralize it: no longer dangerous (in short term)iv. Makes it easier for phagocytes to capture antigens and get rid of them 1. Can clump cells together (agglutination) to make it easier for otherthings to grab onto it. 2. 2 or more antibodies bind to a single dissolved antigen, which forms lattice work of antibody and antigena. Makes it easier for phagocytesv. Can fix and activate complement proteins1. Allows complement proteins to do its various jobs 2. Coat the outer surface of a pathogen a. Gives something for phagocytes to hold on to3. Can enhance the inflammatory process4. Can join together and form a membrane attack complex-group of proteins that insert themselvesvi. Cell lysis: forms pore in surface of foreign cell V. Cell-mediated Immune Response (Cellular immunity)a. Connected to humoral immunityb. Antibodies cannot defend against things that are inside cellsi. Only functional against antigens that are present in extracellar environmentii. Examples:1. HIV infects a host by infecting a cell2. Useless against cancer cells c. T-cells: 2 major typesi. CD4: Have CD4 protein1. Can create CD4 cells, memory cells, helper T-cells, regular T-cellsii. CD8: Have CD8 protein1. Can