Immunology Exam 2 Review.docx

IMMUNOLOGY EXAM 2 REVIEW CH. 60: HUMORAL IMMUNITY What type of immunity is humoral immunity? Antibody-mediated Humoral immunity plays a critical role in protection against ___ pathogens, whereas cell-mediated immunity is more important for protection against ___ pathogens. Extracellular; intracellu...

IMMUNOLOGY EXAM 2 REVIEW CH. 60: HUMORAL IMMUNITY What type of immunity is humoral immunity? Antibody-mediated Humoral immunity plays a critical role in protection against ___ pathogens, whereas cell-mediated immunity is more important for protection against ___ pathogens. Extracellular; intracellular What is humoral immunity directly primarily against? Exotoxin mediated diseases; certain viral infections What specific exotoxins does humoral immunity direct against? Tetanus and diphtheria What specific virulence does humoral immunity direct against? Pneumococci, meningococci, haemophilus influenzae What is the primary immune response? The response when an antigen enters the body for the first time The antibodies are ___ in the serum after a ___ lag period than occurs in secondary response. Detectable, longer About how many days is the lag period? 7-10 days What is the first antibody to be presented when exposed to infection for the first time? Followed by? IgM; followed by IgG or IgA What antibody declines earlier than IgG? IgM The serum antibody concentration continues to rise for ___ ___ then declines. Several weeks What is the secondary response? A second encounter with the same antigen or closely related one months or years after the primary response In secondary response, there is a ___ antibody response and at higher levels than primary response. Rapid What cells are attributed to the rapid antibody response and higher levels than primary response? Memory cells During secondary response, what antibody will be in higher concentration? IgG With each succeeding exposure to the antigen, the antibodies tend to bind the antigen ___ firmly. More What is the lag period in the primary response before antibodies are detected? 7-10 days What is the lag period in the secondary response before antibodies are detected? 3-5 days What antibody type is produced in the primary response? IgM What antibody type is produced in the secondary response? IgG What is the amount of antibody produced in the primary response? Relatively small What is the amount of antibody produced in the secondary response? Relatively large What is the duration of the antibody response in the primary response? Short What is the duration of the antibody response in the secondary response? Long Does affinity maturation occur in the primary response? No Does affinity maturation occur in the secondary response? Yes How does the host cell react when two or more antigens are administered at the same time? By producing antibodies to all of them > competition What are the combined immunizations widely used? DTP vaccine (diptheria, tetanus, pertussis) and MMR vaccine (measles, mumps, rubella) What is the primary function of antibodies? Protect against infectious agents or their products What are the two main functions of antibodies? Neutralize toxins and viruses; Opsonize microorganisms What is opsonization? When antibodies make microorganisms more easily ingested by phagocytic cells What are the two reactions of opsonization? Fc portion of IgG interacts with receptors on the phagocytic surface to facilitate ingestion; IgG or IgM activates complement to yield C3b, which interacts with receptors on the surface of a phagocyte What is the primary antibody in the fetus? IgG because it crosses the placenta Does IgG concentration increase or decrease in the mom after birth? Decreases and lost by 3-6 months What are the processes done for the evaluation of humoral immunity? Measuring amounts of IgG, IgM and IgA How is the evaluation of humoral immunity tested? Patient serum (blood) What are the tests used for the evaluation of humoral immunity? Nephelometry and Immuno-electrophoresis What antibodies can be made by the fetus if an infection occurs? IgG since it crosses the placenta CH. 61: CELL MEDIATED IMMUNITY Cell mediated immunity is an important host defense against? Bacterial and viral diseases (intracellular); Impacts resistance and aids in recovery; Fungi, parasites, and cancers; Rejection of organ transplants What is an example of intracellular infection? Tuberculosis Macrophages present ___ to T cells. Antigens What do helper T cells do? Participate in antigen recognition and regulation functions What do natural killer cells do? Inactivate pathogens What do cytotoxic T cells do? Kills virus infected cells with or without antibodies Macrophages and helper T cells produce ___. What does this do? Cytokines; activates helper and cytotoxic T cells, which leads to killing of the pathogen or tumor cell. What cell does not belong to cell mediated immunity? NK cell What is an example of delayed type hypersensitivity? Tuberculin skin test What does the tuberculin skin test determine? If someone has ever been infected with mycobacterium tuberculosis What suppresses cell mediated immunity? Infection with some viruses What are examples of suppressors of cell mediated immunity? Measles from M. tuberculosis can result in loss of purified protein derivative skin test reactivity What are the tests to determine if someone is immunocompetent? Demonstration of delayed-type hypersensitivity to commonly present antigens; laboratory assessments of T cells What kind of test is used for lymphoid competence? In vivo (skin test) or in vitro (lab test) What do normal results for in vivo tests for lymphoid cell competence say? Will respond with delayed type reaction to skin test antigens, due to past exposure to these antigens What do abnormal results for in vivo tests for lymphoid cell competence say? If no delayed type reaction, could suggest impairment of cell mediated immunity What do normal abilities to produce an in vivo test result for lymphoid cell competence say? Normally, people readily develop reactivity to simple chemicals applied to their skin in lipid solvents and when applied to the area 7-14 days later, they should respond with delayed type reaction. What do abnormal abilities to produce in vivo test results for lymphoid cell competence say? Immunocompromised people with potential incompetent cell mediated immunity fail to develop delayed type reactions What is lymphocyte blast transformation measure? Proliferation of T cells to a drug in vitro What is macrophage migration inhibitory factor? Measured by observing the reduced migration of macrophages in the presence of factor compared with level in controls What does enumeration of T cells, B cells, and subpopulations test measure? The number of each type of cell using a machine What are the types of in vitro tests? Lymphocyte blast transformation; macrophage migration inhibitory factor; enumeration of T cells, B cells, and subpopulations What is the role of adjuvants and lipids in cell mediated reactivity? Enhances uptake of antigen byAPCs; stimulates expression of costimulators; enhances production of cytokines (IL-12) to promote Th-1 cells What is an example of cell mediated immunity suppressed by a viral infection? Tuberculosis CH: 62: MHC COMPLEX, TRANSPLANTATION AND BLOOD TYPE What is MHC? Collection of highly polymorphic genes encoding the proteins that regulate immune responses What is the equivalent for MHC in humans called? Human leukocyte antigen (HLA) What does the success of tissue sand organ transplants depend on? Donors and recipients HLA If the HLA proteins on the donors cells differ from those on the recipient cells, then an ___ ___ occurs. Immune response Where are the genes for HLA proteins clustered in? MHC How many HLA genes are there? 6 (3 for MHC Class 1 and 3 for MHC Class II) What are the 3 HLA genes that code for MHC Class 1 proteins? HLA-A, HLA-B, HLA-C What are the 3 HLA genes that code for MHC Class II proteins? HLA-DP, HLA-DQ, HLA-DR What does it mean when we say a person has TWO haplotypes? Two sets of these genes; ONE paternal, ONE maternal chromosome 6 T/F: HLA genes are very diverse (polymorphic) TRUE What cell surfaces would you find HLA on? Surfaces of leukocytes and tissue cells Each person can make as many as ___ HLA proteins. 12 Expression of HLA genes are ___? Condominant What is the affect of minor antigens on HLA Can be encoded by genes at sites other than HLA locus; can induce a weak immune response that can result in slow graft rejection; the more minor antigens that respond, there will be a more rapid rejection response MHC 1 proteins are found on the surface of all ___. Nucleated cells and platelets MHC 1 proteins are highly ___. Polymorphic MHC 1 proteins have a heavy chain with constant region where ___ binds. CD8+ cytotoxic T cell MHC II proteins are found on the surface of ___. APCs (macrophages, B cells, dendritic cells of spleen, Langerhan’s of skin) MHC II proteins are highly ___. Polymorphic MHC II proteins have two peptides with constant region where ___ binds. CD4+ helper T cells How are peptides bound on MHC I? Endogenously synthesized How are peptides bound on MHC II? Exogenously processed What is the general function of MHC Class I? Elimination of abnormal (infected) host cells by cytotoxic T cells What is the general function of MHC Class II? Presentation of foreign antigen to helper T cells What is the biological importance of MHC? The ability to recognize MHC I vs MHC II to generate the appropriate response in cell-mediated immunity T/F: Many autoimmune diseases occur in people who carry certain MHC genes TRUE T/F: The success of organ transplants is determined by the compatibility of MHC genes of the donor and recipient. TRUE What is an autograft? Self-to-self transplant What is an isograft? Transplant between identical twins What is an allograft? Human-to-human transplant What is a xenograft? Tissue transferred between different species What happens in a first-set allograft rejection process? Reduction in circulation and mononuclear cell infiltration; occurs in 11-14 days; T cell mediated reaction What are the primary reasons for first-set rejections? T cell mediated reactions (skin); antibodies contributions (bone marrow) What happens in a second-set allograft rejection process? If allograft from the same donor is applied to sensitized recipient, it will reject in 5-6 days; caused by pre-sensitized cytotoxic T cells What is the primary reason for second-set rejection? Pre-sensitized cytotoxic T cells Does MHC I or II play a larger role in the acceptance or rejection of transplants? MHC II Does MHC I or II do more of the killing of allograft cells? MHC I (cytotoxic T cells) What is the strength of the allograft rejection response explained by? Direct and indirect process What is the direct process in allograft rejection? Main mechanism for acute rejection; cytotoxic T cells kill graft cells; donors APCs from graft can present either donors or recipients proteins in association with MHC proteins to activate the recipients immune response in lymph node What is the indirect process in allograft rejection? Recipient’s APCs are present on donors proteins; donors self proteins and MHC proteins can be shed and subsequently processed by recipients APC that enter the graft; APC migrates to lymph node where it activates the recipients helper T cells and B cells; results in production of antibodies against the graft and is important in chronic rejection process T/F: Allograft rejection of the fetus does NOT occur. If true, why? TRUE, but the reason is unclear What are the patient results of organ autograft and isograft organ transplants? Patient continues to live normally What are the patient results of xenograft organ transplants? Patient will experience death of cells in the graft within 1 day to 5 weeks after transplantation unless using specific therapy What is the biological importance of MHC? The ability to recognize MHC I vs MHC II to generate the appropriate response in cell-mediated immunity What is an allograft? Human-to-human transplant T/F: Many autoimmune diseases occur in people who carry certain MHC genes. TRUE What is a xenograft? Tissue transferred between different species Does MHC I or II do more of the killing of allograft cells? MHC I (cytotoxic T cells) T/F: HLA genes are very diverse (polymorphic) TRUE What is an autograft? Self-to-self transplant What are 3 primary characteristics about agglutinins? Gamma globulins; produced by bone marrow and lymph gland cells; most of them are IgG and IgM In type O blood, what antibodies are in the plasma? Anti-A and Anti-B antibodies What determines a person’s blood type? Antigen What is the clinical picture of erythroblastosis? Hemolytic anemia; increased bilirubin (jaundice); kernicterus; enlarged liver and spleen What are the effects of immunosuppression on graft rejection? To reduce the rejection of transplanted tissue Is MHC part of innate or adaptive immunity? Adaptive What are the patient results of allograft organ transplants? With patient proper “matching” of tissues between persons, many have had success What are the patient’s result of allograft organ transplants of the kidneys? 5-15 years What are the patient’s results of allograft organ transplants of the liver and heart? 1-15 years What is the treatment of erythroblastosis neonate? Replacement of neonates blood with Rh- blood What antigens cause most blood transfusion reactions? Type A and B antigens What occurs when transfusion of Rh+ blood goes into the same person? Transfusion reaction is greatly enhanced and can be immediate When type A agglutinogen is NOT present in RBCs, what develops in the plasma? Antibodies anti-A agglutinins With multiple exposures to Rh factor, an Rh- person eventually becomes: Strongly sensitized to Rh factor What does immunosuppressive azathioprine do? Inhibits DNA synthesis; blocks growth of T cells What does immunosuppressive mycophenolate mofetil do? Inhibits DNA synthesis What are the two agglutinogens that cause blood cell agglutination? Type A and B antigens Where is the hemoglobin converted to bilirubin by phagocytes excreted? In the bile by the liver What is being activated in the direct process? Activates recipients immune response; acute rejection What is being activated in the indirect process? Activates recipients helper T cells and B cells; chronic rejection If the mother is Rh- and the father is Rh+, she wont have complications during the first pregnancy, but what could happen in later pregnancies? The mother develops anti Rh agglutinins from exposure to the fetus’s Rh+; In future pregnancies, the Rh antibodies attack the Rh+ baby’s blood, causing Rh disease What are agglutinins produced by? Bone marrow and lymph gland cells What is hemolysis? Physical distortion of red blood cells What is used to prevent Rh incompatibility in mothers who are Rh-? RhoGAM In type A blood, what antibodies are in the plasma? Anti-B antibody In type A blood, what antigens are in red blood cells? A antigen In type AB blood, what antibodies are in the plasma? None In type AB blood, what antigens are in red blood cells? A and B antigens What is Kernicterus? Permanent (might be) mental impairment or damage to motor areas of the brain, because of precipitation of bilirubin in the neuronal cells Someone who has type D antigens is said to be? Rh+ What are the two types of antigens that cause blood transfusion reactions? 0-A-B system and Rh system What does immunosuppressive cyclosporine do? Prevents the activation of T lymphocytes by inhibiting IL-2 and its receptor What does immunosuppressive monoclonal antibodies do? Prevents rejection and treats rejection episodes What are some potential symptoms of a transfusion relation? Liver and kidney issues If the red blood cells have become clumped, what is the result? Antibody + antigen reaction What occurs when transfusion of Rh+ blood goes into an Rh- person? No immediate reaction; anti Rh antibodies can develop during the next 2-4 weeks and cause agglutination What is Erythroblastosis Fetalis? Disease of the fetus and newborn child characterized by agglutination and phagocytosis of the fetus’s RBCs When type B agglutinogen is NOT present in RBCs, what develops in the plasma? Antibodies anti-B agglutinins If both A or B agglutinogens are present, what blood type is it? Type AB What do Type A and B genes do? Cause strong agglutinogens What are the 5 immunosuppressive measures used for graft rejection? Cyclosporine, corticosteroids, azathioprine, mycophenolate mofetil, monoclonal antibodies What does immunosuppressive corticosteroids do? Primarily inhibits cytokines IL-1 and TNF (tumor necrosis factor) What causes immune reactions of blood? Antigenicity ___ in the plasma of one blood will react with ___ on the surface of the red cells of another blood type. Antibodies; antigens What two antigens occur on surfaces of red blood cells? Type A and B How many blood types are within the O-A-B system? 4; AB, A, B, O If neither A or B agglutinogens is present, the blood type is: Type O If only A agglutinogen is present, the blood type is: Type A If only type B agglutinogen is present, the blood type is: Type B In type O blood, what antigens are in red blood cells? None In type B blood, what antibodies are in the plasma? Anti-A antibody In type B blood, what antigens are in red blood cells? B antigen What are the two genes that determine the O-A-B blood types? Type O gene and type A and B genes What does type O gene do? It is almost functionless or functionless; it causes no significant type O agglutinogen What are the 3 primary characteristics about agglutinins? Gamma globulins; produced by bone marrow and lymph gland cells; most of them are IgG and IgM What is agglutination? Clumping of red blood cells What are the 6 common types of Rh antigen factors? C,c,D,d,E,e Someone who has no type D antigen is said to be? Rh- If a mother is Rh- and the father is Rh+, what will the baby be? Rh+ All transfusion reactions eventually cause what two things? Immediate hemolysis (from hemolysis); later hemolysis (from phagocytosis of agglutinated cells) How is blood inherited? From genotypes of the mother and father Can a child have a different blood type than both parents? Yes Which antibody mediates Erythroblastosis Fetalis? IgG CHAPTER 63: COMPLEMENT SYSTEM About how many proteins does the complement system consist of? Approximately 20 Complement proteins are synthesized mainly by? The liver Is complement a part of innate or adaptive immunity? Innate What are the 3 main effects of the complement system? Lysis of cells (bacteria, allografts, tumor cells); generates mediators that participate in inflammation and attract neutrophils; opsonization (enhancement of phagocytosis) What is the complement system activated by? Antigen/antibody complexes (immune complex); a variety of nonimmunologic molecules like endotoxins What are 3 pathways of the complement system? Classic, lectin, alternative What is the central molecule of the complement? C3b Which one of the 3 pathways NEEDS to be activated by the immune complex? Classic Which of the pathways DOES NOT need to be activated by the immune complex? Lectin and alternative Which complement pathways are more important in the first time we are infected by a microorganism? Lectin and alternative What are the 2 antibodies that are required to trigger the classic pathway? IgM and/or IgG All three complement pathways lead to the production of ___. C3b What does the C3b on the surface of a microbe mean? Marks foreign and targets it for destruction What are the functions of C3b? Combines with other complement components to generate C5 convertase; opsonizes bacteria What does the antigen-antibody complex activate in the classic pathway and to form what? C1 to form protease In the classic pathway, protease cleaves __ and __ to form __, __ complex. C2; C4; C4b, 2b What is another name for C4b, 2b complex? C3 convertase What is the first complex in the classic pathway? C1 complex What are the components of C3 convertase? C2b, C4b What does C3 convertase cleave into? C3a and C3b What is the anaphylatoxin of the classic pathway? C3a What produces C5 convertase? When C3b binds to C4b, 2b complex What are the components of the membrane attack complex? C5b, C6, C7, C8, C9 What does the membrane attack complex cause? Cytolysis What is the final product of all 3 pathways? Membrane attack complex What does the C1 complex form? Protease What is the central molecule of the complement system pathways? C3b What molecule is involved with the beginning of the lectin pathway that binds to the surface of microorganism? MBL (mannan-binding lectin) MBL activates the: Lectin pathway MBL cleaves C2 and C4 and activates which pathway for following steps? Classic How is the alternative pathway initiated? By binding of C3 (H2O) and factor B The alternative pathway is cleaved by? To produce what? Protease and factor D or produce C3b, Bb How is the complement system regulated at the antibody level? Without antigen-antibody binding, C1 complex cannot be formed and classic pathway cannot be activated; with binding of antigen-antibody complex, it will activate C1 and begin cascade What inactivates the protease activity of C1? C1 inhibitor What is regulation of the alternative pathway mediated by? Binding of factor H to C3b; cleavage of this complex by factor 1 (protease) What reduces the amount of C5 convertase produced? Regulation of alternative pathway Protection of human cells from lysis by the membrane attack complex of complement is mediated by? Decay accelerating factor (DAF, CD55) What is the opsonization effect on the complement system? Microbes are phagocytized much better in the presence of C3b Microbes are phagocytized much better in the presence of? C3b What is the Chemotaxis effect on the complement system? C5a and C5, 6, 7 complex attracts neutrophils What is the most potent anaphlyatoxin of complement? C5a What are the anaphylatoxins of complement? C3a, C4a and C5a What components of complement induce allergic responses? C3a, C4a, C5a How does the membrane attack complex cause Cytolysis? MAC inserts into a “pore” in the membrane where it induces lysis of many types of cells (sometimes good, sometimes bad) How does complement enhance antibody production? Binding of C3b to its receptors on the surface of activated B cells What components of the complement system greatly enhance susceptibility to Neisseria bacteremia and other infections? C5-C8 MBL predisposed to severe? Neisseria infection What component of complement system leads to severe, recurrent pyogenic sinus and respiratory tract infection? C3 What results in angioedema? Inherited deficiency of C1 esterase inhibitor What is an inherited deficiency of complement system? C1 esterase inhibitor If someone has a deficiency in DAF, what pathway is involved? Alternative pathway What is an acquired deficiency in the complement system? DAF resulting in hemolysis If a patient has DAF deficiency, they will have what in their urine? Blood T/F: In transfusion mismatches, complement is NOT activated False; complement is activated and large amounts of anaphylatoxins and membrane attack complexes are generated Anaphylatoxins cause? Shock Membrane attack complexes cause? Red cell hemolysis Patients with severe liver disease are predisposed to infections caused by what bacteria? Pyogenic bacteria Transfusion mismatches are involved in which pathway? Classic What is the slowest pathway and why? Classic because of immune complex required for activation CHAPTER 64: ANTIGEN ANTIBODY REACTIONS IN THE LAB T/F: Reactions between antigens and antibodies are very specific TRUE What is serology? The study of reactions between antibodies and antigens in body fluids What are the 3 major uses of serologic tests? Diagnosis of infectious diseases, diagnosis of autoimmune diseases, determination of blood type and HLA type What are the uses of agglutination? Example? To detect an antibody or antigen and involve agglutination (clumping) of bacteria, RBCs or latex particles; example: standard ABO and Rh blood typing What is the principle of agglutination testing? Based on the presence of agglutinating antibodies in patient sera that can react with specific antigens to form visible clumps What are possible antigens of the agglutination test? Particulate (bacteria and RBCs); inherit particle (latex beads) coated with antigen What are antibodies of agglutination test? Divalent or multivalent; cross links the antigenically multivalent particles and latticework/clumping can be seen Agglutination test determines what? ABO blood type What is the Coombs test for? Hemolytic anemia How does the Coombs test work? The autoantibodies on their surface directed against RBC antigens can be identified using anti-human r-globulin What does a direct Coombs test use? Infants serum What does an indirect Coombs test use? Mother’s serum What is the direct Coombs test? Detects antibodies already on infants RBCs; anti human r-globulin would be added directly to the cells > they would agglutinate (clump) What is the indirect Coombs test? Using the mother’s serum to detect antibodies against RhD+ cells; reaction involves RhD+ cells, mother’s serum and anti human r-globulin Soluble antigens result in the formation of? Insoluble precipitate Antigen precipitate tests can be done in what? Solution or a semisolid medium (agar) A blood specimen is mixed with test antigen to detect what? Patient antibodies What is Nephelometry? The amount of precipitate formed is measured by the optical density of the precipitate where specific antibody densities are measured and compared with a standard curve What are the uses of single diffusion? (Radial immunodiffusion) Measures IgG, IgM, IgA and complement components in serum; measure antibodies to influenza virus in serum; measure antigens in serum What is the principle of the single diffusion (radial immunodiffusion) test? Antibody is incorporated in agar gel; antigen is applied to the well; ring of precipitation is measured and will be directly proportional to the concentration of the antigen What radioimmunoassay (RIA) used to measure? The concentration of antigens through the use of antibodies directed against these antigens What is the principle measurement of radioimmunoassay? Radio emission which gives sensitivity What is the radioallergosorbent test (RAST) used for? To measure the amount of serum IgE antibody that reacts with a known antigen What is the use of the Enzyme Linked Immunosorbent Assay (ELISA) test? Designed for detecting and quantifying soluble substances (peptides, proteins, antibodies, antigens, and hormones) What is the principle of the ELISA test? Based on covalently linking an enzyme to a known antigen or antibody What is the immunofluorescence (fluorescent antibody) test used for? Serological diagnosis of bacterial, viral, fungal and parasitic diseases What is the principle of the immunofluorescence test? Based on the use of UV lights to show the specific combination of antigen with its antibody What is complement fixation test used for? To diagnose infections and rheumatic diseases What is the principle of the complement fixation test? Basis of some tests to detect the presence of specific antibodies or antigens What is the Western Blot test used for? To detect HIV; specific protein molecules from among a mixture of proteins What is the principle of Western Blot test? Detection of target protein by an enzyme reaction using PAGE gel and chemiluminescence What is the flow cytometry (FCM) test used for? To detect, identify and count specific cells and identity particular components within cells What is the principle of the flow cytometry test? Based on measurement of light scattered by particles and fluorescence observed when particles are passed through a laser beam