test Questions FOR DENTISTRY – Immunology2016/2017
- To primary lymphoid organs belong
- thymus
- spleen
- bone marrow
- lymph nodes
- gut
- Peyer´s patches
- appendix
- tonsils
- The thymus is
- a lymphoid organ where intensive cell proliferation and cell death occur
- an organ where T cells aquire antigen-specific receptors
- an organ where T cells aquire markers enabling them to leave the circulation
- an organ where B cells aquire antigen-specific receptors
- an organ that is maximally active late in life
- To secondary lymphoid organs belong
- thymus
- spleen
- appendix
- bone marrow
- lymph nodes
- MALT (mucosa associated lymphatic tissue)
- Peyer´s patches
- Which of the following applies to innate immunity
- high specificity
- involvement of phagocytes and NK cells
- involvement of lymphocytes
- presence of a memory component
- involvement of the complement cascade
- represents an evolutionary young defence strategy
- For adaptive humoral immunity is true that it
- involves HLA class I molecules
- involves helper T cells
- includes antigen presentation to cytotoxic T cells
- involves B cells
- most likely responds to bacterial infections
- involves antibody secretion
- For adaptive cell mediated immunity is true that it
- involves HLA class I molecules
- most likely responds to viral infections
- involves T helper cells
- involves cytotoxic T cells
- involves B cells
- involves antibody secretion
- Mechanisms of adaptive (specific) imunity involve:
- complement system
- T and B cells
- IgE antibodies
- NK cells
- phagocytosis
- secretory IgA antibodies
- Which of the following statements are true for the humoral innate imunity?
- responds to extracellular bacterial infection
- always requires the help from T helper cells
- is responsible for the chronic rejection following the organ transplantation
- involves cytotoxic T cells
- involves B cells
- involves complement activation
- involves secreted antipody
- participates in immunity against intracellular pathogens
- Typical features of specific (adaptive) immunity that distinguish it from non-specific (innate) immunity are:
- memory
- specificity
- immortality
- ability to act against extracellular bakteria
- no role in antitumor immune response
- Which of the following statements are true?
- TH cells express CD4 and recognize antigenic peptides associated with class II MHC molecules
- the pluripotent stem cell is one of the most abundant cell types in the circulation
- activation of macrophages increases their expression of class I MHC molecules, enabling them to present phagocytosed antigen more effectively
- lymphoid follicles are present only in the spleen and lymph nodes
- infection has no influence on the rate of hematopoiesis
- all lymphoid cells have specific antigen-binding receptors in their membranes
- all vertebrates generate B lymphocytes in the bone marrow
- At what age does the thymus reach its maximal size?
- during the first year of life
- teenage years (puberty)
- between 40 and 50 years of age
- after 70 years of age
- Haptens
- require carrier molecules in order to be immunogenic
- are small molecules
- are immunogenic
- are usually lipids
- cannot induce an immune response by themself
- are able to bind to specific antibodies
- can stimulate secondary antibody responses without carriers
- can induce only cell-mediated immune response
- Which of the following statements are true?
- most antigens induce a response from more than one clone of lymphocytes
- a large protein antigen generally can combine with many different antibody molecules
- a hapten can stimulate antibody production but cannot combine with antibody molecules.
- MHC genes play a major role in determining the degree of immune responsiveness to an antigen
- epitopes recognized by B-cell receptors can be nonsequential amino acids brought together by the tertiary conformation of a protein antigen
- both TH and TC cells recognize antigen that has been processed and presented with an MHC molecule
- each MHC molecule binds a single unique peptide
- all proteins are immunogens
- Indicate, which of the following statements regarding haptens and carriers are true:
- haptens are large protein molecules such as bovine serum albumine
- when a hapten-carrier complex containing multiple hapten molecules is injected into an animal, most of the induced antibodies are specific for the hapten
- carriers are needed only if one wants to elicit a cell-mediated response
- it is always necessary to immunize with a hapten-carrier complex in order to obtain antibodies directed against the hapten
- haptens include small molecules such as dinitrophenol and penicillinic acid (derived from penicillin)
- carriers include small molecules such as dinitrophenol and penicillinic acid (derived from penicillin)
- Indicate which of the following statements is true
- Most antigens induce a polyclonal response.
- A large protein antigen generally can combine with many different antibody molecules.
- A hapten can stimule antibody formation but cannot combine with antibody molecules.
- Proteins are better antigens than lipids.
- Small molecules are better antigens than large molecules.
- All protein molecules have the same immunogenicity.
- To the features of antigens belong:
- high molecular weight
- chemical complexity
- sufficient degradability
- foreigness
- opsonisation
- memory
- An immunologic adjuvant is a substance that
- reduces the toxicity of an immunogen
- enhances the immune response against the immunogen
- enhances hematopoiesis
- enhances the immunogenicity a hapten
- modifies the specificity of T-cell receptors
- decreases the avidity of antibodies
- Binding between an antigen and antibody:
- is reversible
- is covalent
- contains hydrogen bonds
- is irreversible
- contains disulfidic bonds
- is non-covalent
- contains van der Waals forces
- contains electrostatic bonds
- Indicate which statements are true for epitopes recognized by B-cells
- they always consist of a linear sequence of amino acid residue
- they may lose their immunogenicity when a protein antigen is denatured by heat
- immunodominant epitopes are determined in part by the MHC molecules expressed by an individual
- they are present in protein antigens only
- multiple different epitopes may occur in the same antigen
- their immunogenicity may depend on the three-dimensional structure of the antigen
- Complete antigens include:
- proteins
- polysaccharides
- glycolipids
- lipids
- native nucleic acids
- Which of the following cells are phagocytic?
- macrophages
- T-lymphocytes
- B-lymphocytes
- NK cells
- monocytes
- neutrophils
- eosinophils
- polymorphonuclear leukocytes
- Which of the following white blood cells further differentiate in tissues?
- neutrophils
- eosinophils
- basophils
- monocytes
- Professional phagocytes are:
- neutrophils
- eosinophils
- basophils
- monocytes
- macrophages
- T lymphocytes
- B lymphocytes
- plasma cells
- The structure formed by the fusion of engulfed material and lysosomes within the phagocytic cell is called a
- phagosome
- vacuole
- lysosome
- phagolysosome
- endolysosome
- Indicate which of the following statements concerning phagocytosis are true
- opsonisation involves adsorption of opsonins to the surface of bacteria or other particles
- opsonisation means chemical degradation of bacteria cells or other particles
- C3b is an important opsonin
- the main serum opsonin is CRP
- endogenous chemotaxins (chemoattractants) include C5a, IL-8, leukotriens
- phagocytosis can be realized only through Fc-receptors, CR1 and CR3
- respiratory burst is a dramatic increase in oxygen consumption and superoxide formation
- the basic enzyme of respiratory burst is myeloperoxidase
- the basic enzyme of respiratory burst is NADPH oxidase
- Components of the complement system are synthesised by
- lymphocytes
- plasma cells
- eosinophils
- hepatocytes
- monocytes/macrophages
- neutrophils
- Alternative complement pathway is activated by
- mannose-binding lectins
- yeast walls
- bacterial cell walls
- bacterial lipopolysaccharides
- nucleic acids
- aggregated immunoglobulins
- viruses
- To regulators of the complement system belong
- Lactoferrin
- Myeloperoxidase
- Factor Q
- Membrane attack complex (MAC)
- C1 inhibitor
- C4-binding protein
- Factor H
- Decay accelerating factor DAF
- Factor I
- Consequences of complement activation are
- enhancement of opsonisation
- enhancement of chemotaxis
- major basic protein formation
- decrease of inflammation
- removal of immune complexes
- complement mediated cytolysis
- production of anaphylatoxins
- Indicate which of the following statements is true
- A single molecule of bound IgM can activate the C1q component of the classical complement pathway.
- C3b fragment can act as an opsonin.
- All complement components are present in serum in a functionally inactive proenzyme form.
- Nucleated cells tend to be more resistant to complement-mediated lysis than red blood cells.
- Enveloped viruses cannot be lysed by complement because their outer envelope is resistant to pore formation by MAC.
- C4-deficient individuals have difficulty eliminating immune complexes.
- The classical complement pathway is activated by:
- most viruses
- antigen-antibody complexes
- antigen-antibody complexes containing only secretory IgA
- CRP
- haptens
- What is true for complement components:
- They are normally present in serum.
- They are synthesised in the liver.
- The complex C4b2a acts as C5 convertase.
- The most important complement component is factor C3.
- C1q is involved in the lectin pathway of activation.
- They can be ocasionally produced by plasma cells.
- Indicate the correct statements:
- Classical pathway is activated by binding C1 to antigen-antibody complexes.
- MAC forms a channel in the target cell membrane.
- Small amounts of C3b are continously present in plasma.
- Lectin pathway is activated by MBL.
- Complement activation is regulated by the blood clotting system.
- There are three pathways of complement activation: classical, altenative and lactoferrin.
- Classical pathway is activated mainly by complexes of antigens and IgE antibodies.
- Which of the following is referred to as C3 convertase?
- C4b2a
- C3bBb
- C3bD
- C3b(H2O)Bb
- C4b2aC3b
- C3bBbC3b
- Which of the following is true for the membrane attack complex?
- The same components are involved in all pathways of activation.
- MAC has a composition of C5bC9n.
- MAC causes polymerization of the target cells.
- MAC allows passage of ions and water and subsequent lysis of target cells.
- C9 must always be attached for lysis to occur.
- C9 polymerizes to form a transmembrane channel.
- A lack of CR1 receptors on red blood cells results in
- decreased binding of C3b to red blood cells
- lack of clearance of immune complexes by the spleen
- increased breakdown of C3b to C3Bb and C3BbC3
- increased production of C3 convertase
- Which complement-mediated functions remain intact in a patient lacking C3?
- lysis of bacteria caused by MAC
- opsonisation of bacteria
- generation of anaphylatoxins
- generation of chemotactic factors for neutrophils
- Active fragments of complement component C5 cause
- contraction of smooth muscles
- attraction of neutrophils
- vasodilation
- degranulation of mastocytes and basophills
- clearens of immunocomplexes
- Which of the following molecules act as complement regulatory proteins?
- membrane inhibitor of reactive lysis
- protectin
- membrane-attack complex (MAC)
- interleukin-1
- factor E
- membrane cofactor protein (MCP)
- ceruloplasmin
- C-reactive protein (CRP)
- α-antitrypsin
- What is true for positive acute phase proteins?
- rapid increase following infection
- nonspecific indicators of inflammation
- include pentraxin 3 and α2-macroglobulin
- the major members are CRP and serum amyloid A
- C-reactive protein acts as a non-specific opsonin
- C-reactive protein decreases 100 -1000 fold during inflammation
- include IL-1, IL-6 and TNF
- are synthesised in the liver
- they synthesis is under the control of TNF, IL-1 and IL-6
- are synthesised by plasma cells
- Indicate which of the following statements are true:
- chemokines are chemoattractants for lymphocytes but not for other leukocytes
- integrins are expressed on both leukocytes and endothelial cells
- leukocyte extravasation involves multiple interactions between cell-adhesion molecules
- most secondary lymphoid organs contain high-endothelial venules (HEVs)
- ICAM-1 is an endothelial adhesion molecule that binds to E-selectin
- granuloma formation is a common symptom of local inflammation
- Which of the following components of natural immunity contribute to acute inflammation?
- cyclosporine A
- histamine
- PGE2
- hydrocortizone
- neutrophils
- interleukin-1
- interleukin-6
- tumor necrosis factor
- According to the clonal selection theory
- lymphocytes bear multipotential receptors that become specific after contact with antigen
- lymphocytes bear receptors that have genetically determined specificities
- macrophages ingest antigens and make RNA copies that are transferred to T cells
- virgin B cells acquire specific receptors only after contact with antigen
- both B- and T-cell precursors in the bone marrow already have their specificities fixed
- Which of the following cells produce IgE?
- mast cells
- basophils
- eosinophils
- plasma cells
- neutrophils
- Human IgM
- is involved in ADCC reactions
- can pass through the placenta
- can activate the complement
- is a pentamer or a hexamer
- is produced in the primary immune response
- IgM is usually present in monomeric as well as dimeric form.
- include natural isohemagglutinins
- has a half-time of 5 days
- Monoclonal antibodies (MoAb):
- are formed exclusivelly to protein antigens
- contain only one binding site
- are only of the IgM class
- are produced in vitro by the hybridoma technique
- have identical antigen binding sites
- have been used with linked toxins as immunotoxins
- are produced by hybridisation of myeloma cells and B cells
- Immunoglobulin IgA
- binds to Fc receptors on masts cells
- is the most abundant immunoglobulin class in serum
- is present in secretions such as saliva, tears, and colostrum
- is present on the surface of immature B cells
- is the first serum antibody made in a primary immune response
- plays an important role in type I hypersensitivity
- plays an important role in protecting against pathogens that that invade trought the gut or respiratory mucosa
- activates complement by the classical pathway
- participates in antibody-dependent cell-mediated cytotoxicity (ADCC)
- Immunoglobulin IgG
- binds to Fc receptors on masts cells
- is the most abundant immunoglobulin class in serum
- is present on the surface of immature B cells
- is the first serum antibody made in a primary immune response
- plays an important role in type I hypersensitivity
- plays an important role in protecting against pathogens that that invade trought the gut or respiratory mucosa
- activates complement by the classical pathway
- participates in an antibody-dependent cell-mediated cytotoxicity (ADCC)
- Physiologic function of IgE molecules is mediating/providing
- immunity to parasites and helmints
- anaphylactic reactions
- contractions of smooth muscles
- immunity to viruses
- mucosal immunity
- function is unknown
- Human IgG
- can pass the placenta
- can be cleaved by pepsin and yet remains divalent
- has a half-time of app. 23 days
- can activate the complement
- is involved in hypersensitivity type I reactions
- is an opsonizing antibody
- is involved in ADCC reactions
- can neutralize toxins
- is present on basophils and mast cells in allergic people
- Which of the following statements are true for IgG?
- secreted form is a pentamer of the basic H2L2 unit
- binds to Fc receptors on mast cells
- multimeric forms have a J chain
- present on the surface of mature, unprimed B cells
- the most abundant isotype in human plasma
- major antibody in secretions such as saliva, tears, and breast milk
- present on the surface of immature B cells
- the first serum antibody produced in the primary immune response
- plays an important role in immediate hypersensitivity
- activates the classical pathway of the complement system
- Which of the following statements are true for IgM?
- secreted form is a pentamer of the basic H2L2 unit
- binds to Fc receptors on mast cells
- multimeric forms have a J chain
- present on the surface of mature, unprimed B cells
- the most abundant isotype in serum
- major antibody in secretions such as saliva, tears, and breast milk
- present on the surface of immature B cell
- the first serum antibody produced in the primary immune response
- plays an important role in immediate hypersensitivity
- activates classical pathway of complement
- Which of the following statements are true for IgE?
- secreted form is a pentamer of the basic H2L2 unit
- binds to Fc receptors on mast cells
- multimeric forms have a J chain
- present on the surface of mature, unprimed B cells
- the most abundant isotype in serum
- major antibody in secretions such as saliva, tears, and breast milk
- present on the surface of immature B cells
- the first serum antibody produced in the primary immune response
- plays an important role in immediate hypersensitivity
- activates classical pathway of complement
- Which of the following statements are true for IgA?
- secreted form is a pentamer of the basic H2L2 unit
- binds to Fc receptors on mast cells
- multimeric forms have a J chain
- present on the surface of mature, unprimed B cells
- the most abundant isotype in serum
- major antibody in secretions such as saliva, tears, and breast milk
- present on the surface of immature B cells
- the first serum antibody produced in the primary immune response
- plays an important role in immediate hypersensitivity
- activates classical pathway of complement
- Indicate which of the following statements is true (+) or false (-):
- J-chain is a part of the IgE dimer
- In the primary immune response, IgM antibodies appear first
- IgG antibodies are formed mainly to corpuscular antigens
- IgD antibodies are formed mainly to food allergens
- IgM is present mainly in human plasma
- Antibodies represent the gammaglobulin fraction of the human serum.
- Polyclonal antibodies are normally produced in vivo, whereas monoclonal antibodies in vitro.
- Monoclonal antibodies are prepared by lymphocyte hybridisation with myeloma cells.
- Immunotoxins are conjugates of monoclonal antibodies and cytotoxic molecules.
- Indicate which of the following statements is true (+) or false (-)
- Allotypes represent allelic alternatives of a single structural gene.
- Class switching arises when a B cell switches the type of light chain expressed.
- Class switching arises when a B cell switches the type of heavy chain expressed
- Antibody diversity arises from a variety of mechanisms including multiple germline V genes, combinatorial joining of the variable region gene segments, and somatic mutation.
- Idiotypes are antigenic determinants found only in the antigen-binding sites of antibodies
- The secretory IgAmolecule has a monomeric structure.
- The IgM molecule is a pentamer combined with one J chain.
- The class-specific antigenic determinants of immunoglobulins
- determine isotypes
- determine idiotypes
- determine allotypes
- are the same within species
- are located in the constant domains of H and L chains
- are located in the constant domains of the H chains only
- are located in the constant domains of the L chains only
- are located in in the variable regions of the H and L chains
- Indicate which of the following statements is true (+) or false