CUNI Immunology

Which cells are of the lymphoid lineage?. B cells. T cells. NK cells. Dendritic cells. Macrophages. Neutrophils. Eosinophils. Mast cells. Red blood cells. Megakaryocytes.

Is there a specific Ig isotype for mucosa-associated lymphoid tissue (MALT)?. Yes, dimeric IgA. Yes, monomeric IgA. Yes, IgG. only a little bit of IgE. IgM.

Idiotype is a... Set of allo-structures in the variable Ig domain. Self structure on the Ig molecule. Any self structure on the Ig molecule. Set of allo-structures in the anywhere in the Ig molecule.

Which cytokine inhibits Th1 cell development?. IL-4. IL-2. IL-10. IL-17. IFN-gamma.

Which molecular mechanism is taking part during the Ig isotype class switch recombination (CSR)?. Cytidine deamination (induces DNA breaks). somatic recombination (removal of DNA pieces). epigenetic regulation by cytokines (turns heterochromatin to euchromatin). RNA splicing. transcriptional silencing.

Which genetic defect can cause severe combined immunodeficiency (SCID)?. Mutation in the common gamma receptor chain for IL-2 family. mutation linked to thymic deficiency. mutation in TAP responders. mutation in RAG recombinases. mutation in proteasome subunits.

The allergic reaction is a type of hypersensitivity. Which molecules are essential in the effector phase?. IgE. histamin. the high-affinity Ig receptor on the surface of degranulating cells. heparin. IgA.

Which cytokines stimulate the differentiation of Th1 cells?. IFN-gamma. IL-12. IL-18. IL-3. IL-4.

There are 3 critical pathways that regulate the T-cell outcome, the following statement is true for naive T-cells: NF-kB and PI3K pathways serve as survival pathways promoting long term cycling and are considered as costimulatory. MAPK pathway activity is being upregulated after the costimulation signal. the balance between NFAT/MAPK (AP-1~Fos-Jun) regulates the decision between full activation and anergy of T-cells. FoxP3 pathway serves as a suppresive by binding to NFAT and blocking NFAT/AP-1 heterodimer assembly. MAPK is the target of immunosuppresive drugs widely used in clinics.

Which molecule serves as a target for the TLR receptor?. Viral ss/dsRNA and dsDNA. LPS/endotoxins/peptidoglycans. unmethylated CpG. PAMP and DAMP. antigen.

Antigen is: a structure towards which the adaptive immune response is directed. the target for generation of specific immune memory. proteolytically processed into antigenic peptides, which are then recognized by TCR. a structure which initiates the innate immune response. any foreign structure entering the organism.

Which basic killing mechanisms are used by T cells?. contact-dependent Fas ligand binding to the Fas receptor on the target cell. release of granules containing perforin and granzymes inducing apoptosis in target cell. release of granules containing biologically active amines and fatty acyl metabolites. perforin induces plasma membrane lysis in the target cell. engulfment of the target cell and its intracellular killing.

Which class of receptors use cytoplasmic signaling molecules of Jak and STAT families?. the IL-2 family. BCR/TCR. IL-1 receptors. Fc receptors. KIR.

What is the biological importance of MHC locus polymorphism?. enhancement of species survival (generation of variability within the population of a single species). establishment of a high population diversity to be able to react against all viral and microbial mutants. an efficient and broad antigenic peptide presentation within an organism to initiate adaptive immune response in the population. keeping tissue homeostasis within an individual and limiting/restricting the cellular transmission between organism (transmissive cancers, e.g.). keeping as many homozygotic combinations of MHC molecules as possible – necessary for effective positive and negative selection in the thymus.

What is "Transcytosis"? Where does it play an important immunological role?. the transport of immunoglobulins (mainly IgA) from submucosa to gut lumen. entry of cells into the lymph node via HEV (high endothelial venules). transport of cells through the endothelial layer of veins and capillaries. transport of the material from the capillaries to the CNS through blood-brain barrier.

Affinity is... the strength with which a monovalent ligand interacts with a receptor binding site. an equilibrium state with the ratio of ON (Kon) and OFF (Koff) rates between 2 interacting partners (Resulting in their actual concentrations in M). similar for immobilized (in 2D such as interacting opposing membrane receptor/ligand pairs) and in solution (3D such as free ligand/immobilized receptor) interaction of the reactants. measured quantitatively as the affinity constant Ka, equals to inverted dissociation constant 1/Kd. the result of the process of somatic hypermutation in Ig locus in the lymph node germinal centers.

Each antigen binding site is composed of these structural and genetic elements: 6 CDR loops. 2 variable Ig domains encoded by 2 independent genes. 3 CDR loops. 2 variable IG domains encoded by a single gene after VDJ recombination. 1 variable and 1 constant Ig domain after class switch recombination encoded by a single gene.

What is the main costimulatory receptor on a T-cell delivering 2nd signal during naive T-cell activation?. CD28. CD4 or CD8. CD40. CD40L. CTLA4.

Which enzymes initiate TCR signal transduction?. Tyrosine kinases. Ser/Thr kinases. ubiquitinyl ligases. proteases. phospholipases.

What are proteasomes doing in the cell? Where are they?. cytoplasmic (and nucleoplasmic) organelles involved in protein degradation. extracellular organelle important for primitive antiviral response degrading viruses (also present in plants). organelles derived from endosomes/lysosomes where MHC-II molecules bind antigenic peptides. organelles localized in the nucleus involved in alternative splicing of hnRNA. cytoplasmic organelles involved in protein synthesis.

Which type of protein superfamily domains are the most frequent ones in the extracellular part of membrane receptors?. immunoglobulin. leucine-rich repeats. C-lectin. mucin. fibronectin.

What is a xenotransplant?. transplant derived from a different species. transplant derived from a different individual, belonging to the same inbred strain. transplant derived from a different individual, belonging to a different inbred strain. transplant derived from a the same individual, but from a different body location.

What is the major difference between innate and adaptive immune systems?. memory is higher in adaptive immunity. dominant inhibition is crucial for innate immunity immediately at the onset of a response. speed of the response is higher in innate immunity. innate immunity has a high inherited variation in the germline. diversity is higher in innate immunity.

What is the major role of MHC glycoproteins?. Antigen presentation to T-cells. regulation of apoptosis in antigen-presenting cell. costimulation of antigen-presenting cells. adhesion and homing of T cells. targeting of endocytosed material for proteolytic degradation.

Which mechanisms do tumors use to prevent immune system attacks?. attracting and educating immunosuppressive cells (producing Treg and MDSC). expressing of the Fas ligand (mimicking immunologically privileged sites). downmodulating MHC-I expression to prevent T-cell (and other leukocyte) recognition. induction of neovascularization with excessive tight junctions resembling the blood-brain barrier and preventing immune cells from entering the tumor. production of immunosuppressive cytokines in the tumor.

Which cells are major targets for the following cytokines?. Neutrophils -> IL-17. Bone marrow hematopoetic stem cells -> G-CSF. T-cells -> IL-4. B cells -> IL-2. Macrophages -> IL-12.

Which cells are the major (professional) phagotic cell types?. neutrophils. macrophages. basophils and mast cells. T cells and NK cells. dendritic cells.

The invariant TCR clones do show distinct function to conventional T-cells - which subsets are these?. Gamma-delta T-cells (Vg9/Vd2). NKT cells. All CD8+ T cells. All CD4+ T cells. Treg cells.

What role do M-cells serve?. transfer material (antigens or microbes) from the gut lumen to mucosa-associated lymphoid tissue (MALT). bronchial and gut sampling of ingested antigens. mucosa-associated inhibition of T-cell responses. support for epithelial regeneration in the gut from stem cells. maturation of B-cell precursors into B1 cell population.

Innate immunity is... Composed of anatomic barriers, potent endo/phagocytic activity, killing and inflammatory mechanisms. Targeting hundreds of conserved structures (DAMPs and PAMPs). Non-antigen-specific host defense mechanisms that initiate response prior to antigen response. Clonal at the cellular level. not essential for pathogen removal - this is the duty of adaptive response only.

Which immune mechanism is important in defense against multicellular parasites?. IgE bound to FcERI receptors. mast cell+basophil+eosinophil activity. cytotoxicity mediated by NK cells. production of extracellular matrix. activation of surface Fc gamma receptors via crosslinking followed by elevation of intracellular Ca2 ion concentration triggering exocytosis.

The effector phase of diverse hypersensitivity types of immune reaction spans the time of... seconds to days. variable, since it matters if there is a local or systemic presence of the target and effector molecules (more systemic=faster). there is simply a continuum of time courses of hypersens. categories, since there are intermediate states involving more mechanisms. seconds to minutes - since all are based on the systemic presence of high levels of preformed soluble molecules of T cell clones and are all therefore very fast, both in the case of humoral and cellular immunity. minutes to hours.

What is the biological role of the invariant chain of MHC-II?. filling the antigen binding groove in the secretory pathway (namely ER and GA). minimizing the loading of self-peptides on MHCII. targeting and recycling MHCII to the MHCII compartment (MIIC). trimerisation of de-novo synthetised MHCII molecules. the facilitation of exogenous peptide binding.

Secreted immunoglobulin binds with CDR loops to... virions and bacterial cells directly. naive unprocessed structural antigen (which can also be discontinuous). T cells. MHC-I/II loaded with a peptide. B cells to form surface BCR.

What is the physiological effector mechanism of antibodies?. activation of effector leukocyte populations (NK cells and macrophages) initiating killing or phagocytosis after opsonization and binding to their Fc-ends. neutralization of viruses and microbes by blocking their binding to target cells. opsonization (by targeting complement or other brigading molecules to the cells surface (includes antibodies). signal transduction in B-cell development through membrane Ig. initiate inflammation via the process of neutrophil degranulation.

Which Ig isotype is characteristic for the mucosal humoral response?. IgE. dimeric IgA. monomeric IgA. IgM. IgG.

In TCR and BCR receptor complexes, the ITAM motifs are present in... transmembrane adaptor proteins. CD3 (epsilon, gamma, delta, zeta chains) and CD79 (Ig-a and -b). associated CD4/CD8 coreceptors in their intracellular tails. associated signaling molecules, such as Src family kinases. TCR and BCR itself.

Which type of immune response is effective in tumor elimination?. NK cell killing in both directions of missing-self and stress-induced self. T-cell response (by both CD4+ and CD8+). macrophage phagocytosis. antibody response. chronic inflammatory response.

Which substances are in a neutrophil?. superoxides. hydrogen peroxide. HCl acid.

What facilitates the adhesion of innate immunity cells?. integrins. selectins. TCR/BCR. C-lectin.

What are the waves of signal transduction via TCR?. first wave is Src, second wave is Syk (of phosphorylation). first wave is Syk, second wave is Src (of phosphorylation). waves involving SHIP phosphatases.

Valency is... the numeric count of overall binding sites of a molecule.

Which receptors recognize DAMPs and PAMPs on dendritic cells?. PRR. NLR. TLR.

*Which are the effector cytokines driving suppression in the immune system?. IL-10. TGF-beta. IFN-gamma. IL-4. IL-17.

*In which cellular compartments/organelles does the peptide bind to the MHC-I molecule?. ER positive for TAP transporters. Golgi apparatus. endosomal secretory vesicle. cytoplasm with proteasome. phagolysosome.

*What receptors/coreceptors does HIV bind to?. CD4. CCR5/CXCR4. CD8. MHC-I/II. gp120.

*Th17 CD4+ T-cells are NOT... differentiating from naive CD4 Th in secondary lymphoid organs. characterized by IL-17 production. playing an indispensable role in intracellular pathogen protection. playing a critical role in extracellular pathogen protection in mucosal tissues.

*Which mechanisms are specific for rapid innate IS response against pathogens?. phagocytosis. complement and coagulation cascades. ADCC and missing self-targeted cellular cytotoxicity. cytokine production. antibody production.

*Name TCR coreceptors and their recognized ligands on APC. CD-8 -> MHC-I. CD4 -> MHC-II. CD4 -> CD80. CD8 -> CD40. CD40L -> CD40.

*Which antibody part is responsible for any of its effector function?. whole Fc part - each particular function is associated with a different function. Fab part. CDR loops in the antigen binding site. hinge region. specific region in the Fc part to.

*Which cell type is removing dead/dying cells from tissues?. macrophages. neutrophils. mast cells. eosinophils. basophils.

*Positive selection of thymocytes in the thymus is mediated by... cortical Thymic Epithelial Cells (cTECs). medullary Thymic Epithelial Cells (mTECs). thymic Dendritic cells. all of the above.

*Which approaches are used before/during/after organ transplantation in clinics?. host/donor HLA match testing. KIR/MHC mismatch for assesment of NK cell reactivity. immunosuppression using drugs targeting NFAT signaling in T-cells. search for the best host-donor match in their TCR repertoire. immunosuppression using drugs targeting TAP responder mutations.

*Which cells initiate the allergic reaction?. mast cells. basophils. macrophages. eosinophils. dendritic cells.

Epitope is a... part of an antigen recognized by the immune system (CDR loops of Ig specifically). part of an Ig molecule containing CDR loops that binds to a specific part of an antigen. a particle that has the capability of mitigating immune response. a particle that propagates the immune system.

B-cell receptors can be... monovalent. bivalent. decavalent.

The most common leukocyte in the blood is a... neutrophil. macrophage. NK cell. eosinophil. basophil.

Immunoglobulins capable of complement activation are... IgG. IgM. IgE. IgA. IgD.

The most common Immunoglobulin type is... IgG. IgM. IgA. IgE. IgD.