Is there a specific Ig isotype for mucosa-associated lymphoid tissue (MALT)? Which one? only a little bit of IgE yes, IgG yes, dimeric IgA IgM yes, monomeric IgA.
Idiotype is: a set of allo-structures in the variable Ig domain self structure on the Ig molecule any structure in the variable Ig domain, including the paratope any self structure on the Ig molecule a set of allo-structures anywhere in the Ig molecule.
Which cytokine inhibits Th1 cell development? IL-2 IL-4 IL-10 IL-17 IFN-gamma.
Which molecular mechanism is taking part during the Ig isotype class switch recombination
(CSR)? RNA splicing somatic recombination transcriptional silencing cytidine deamination epigenetic regulation by cytokines.
Which genetic defect can cause severe combined immunodeficiency (SCID)? a mutation in the common gamma receptor chain for interleukin-2 family a mutation linked to thymic deficiency a mutation in TAP transporters a mutation in RAG recombinases a mutation in proteasome subunits.
The allergic reaction is a type of hypersensitivity. Which molecules are essential in the effector
phase? high-affinity Ig receptor on the surface of degranulating cells IgA IgE histamin heparin.
Which cytokine(s) stimulate the differentiation of Th1 cells? IL-18 IL-12 IFN-gamma IL-3 IL-4.
There are 3 critical pathways that regulate the T cell outcome. The following statement is true for
naive T cells: MAPK is the target of immunosuppressive drug widely used in clinics 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 cell FoxP3 pathway serves as a suppressive by binding to NFAT and blocking NFAT/AP-1 heterodimer
assembly.
Which molecule serves as a target for TLR receptors? viral ss/dsRNA and dsDNA LPS / endotoxin, peptidoglycan unmethylated CpG antigen PAMP and DAMP.
Antigen is: a structure, towards which the adaptive immune response is directed a structure, which initiates the innate immune response the target for generation of specific immune memory any foreign structure entering the organism proteolytically processed into antigenic peptides, which are then recognized by TCR.
Which basic killing mechanisms are used by T cells? release of granules containing biologically active amines and fatty acyl metabolites 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 perforin induces plasma membrane lysis in the target cell engulfment of target cell and its intracellular killing.
Which class of receptors use cytoplasmic signaling molecules of Jak and STAT families? IL-1 receptors BCR/TCR Fc receptors KIR Incorrect IL-2 family receptors.
What is the biological importance of MHC locus polymorphism? enhancement of the species survival (generation of the variability within the population of
individuals of a single species) establish high population diversity to be able to react against all viral and microbial mutant
variants keeping as many homozygotic combinations of MHC molecules as possible – necessary for effective
positive and negative selection in the thymus an efficient and broad antigenic peptide presentation within an organism to initiate adaptive
immune response in the population of individuals keeping tissue homeostasis within an individual and limit/restrict the cellular transmission between
organisms – e.g. transmissive cancers.
What is “transcytosis” and where it plays an important immunological role? 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 transport of immunoglobulins (IgA) from submucosa to the gut lumen transport of apoptotic bodies from submucosa into the intestinal lumen.
Affinity is: an equilibrium state with the ratio of ON (Kon) and OFF (Koff) rates between 2 interacting
partners (resulting in their actual concentrations in M) the strength with which a monovalent ligand interacts with a receptor binding site similar for immobilized (in 2D such as interacting opposing membrane receptor/ligand pairs) and in
solution (3D such as free ligand/immobilized receptor) interactions 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: 2 variable Ig domains encoded by a single gene after VDJ recombnation 1 variable and 1 constant Ig domain after class switch recombination encoded by a single gene 3 CDR loops 6 CDR loops 2 variable Ig domains encoded by 2 independent genes.
What is the main costimulatory receptor on T cell delivering 2nd signal during activation of naive
T cell? CD4 or CD8 CTLA4 CD40L CD28 CD40.
Which enzymes initiate TCR signal transduction? tyrosine kinases ubiquitinyl ligases proteases phospholipases serine/threonine kinases.
What are proteasomes doing in the cell? Where in the cell are these organelles present? 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 cytoplasmic (and also nucleoplasmic) organelles involved in protein degradation 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? fibronectin mucin immunoglobulin leucine-rich repeat C-lectin.
What is a xeno-transplant? is derived from a different individual, belonging to the same inbred strain of mouse is derived from an artificial tissue generated in the tissue culture is derived from a different species is derived from a different individual, belonging to a different inbred strain of mouse is derived from the same individual but a different body location.
What is the major difference between innate and adaptive immune systems? dominant inhibition is crucial for innate immunity immediately at the onset of the response memory is higher in adaptive immunity diversity is higher in innate immunity Incorrect speed of the response is higher in innate immunity inherited variation in the germline is high in innate immunity.
What is the major role of MHC glycoproteins? antigen presentation to T cells regulation of apoptosis in antigen-presenting cells costimulation of antigen-presenting cells adhesion and homing of T cells targeting of endocytosed material for proteolytic degradation.
What are the mechanisms used by tumors to prevent attack by the immune system? attraction and education of immunosuppressive cells (Treg, MDSC) induction of neovascularization with excessive tight junctions resembling blood-brain barrier and
preventing immune cells to enter the tumor production of immunosuppressive cytokines in the tumor expression of Fas ligand – mimicking immunologically privileged sites downmodulation of MHC class I expression to prevent T cell recognition.
Which cells are the major targets of the following cytokines: neutrophil / IL-17 macrophage / IL-12 bone marrow hematopoetic stem cells / G-CSF B cells / IL-2 T cells / IL-4.
Which cells are the major phagocytic cell types? basophil and mast cell macrophage T cells and NK cells dendritic cell neutrophil.
The invariant TCR clones do show distinct function from conventional T cells - identify those
oligoclonally-reactive T cell subsets. all CD8+ T cells all CD4+ T cells gamma delta T cells (mainly Vg9/Vd2) T regulatory cells NKT cells.
What is the role of M-cells? transfer of material (antigens and microbes) from gut lumen to the mucosa-associated lymphoid
tissue (MALT) 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 bronchial and gut sampling of ingested antigens.
Innate immunity is: not essential for pathogen removal - this is the duty of adaptive response only composed of anatomic barriers, potent endocytic/phagocytic activity, killing and inflammatory
mechanisms clonal at the cellular level targeting hundreds of conserved structures (PAMPs and DAMPs) non-antigen specific host defense mechanisms that initiate immune response prior to the response to
an antigen.
Which immune mechanism is important in defense against multicellular parasites? IgE bound to FcERI receptors cytoxicity mediated by NK cells production of extracellular matrix activity of mast cells, basophils and eosinophils 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 minutes to hours seconds to minutes - since all are based on the systemic presence of high levels of preformed soluble
molecules of (usually antibodies) or T cell clones and are all therefore very fast - both in case of
humoral and cellular immunity variable, since it matters if there is a local or systemic presence of the target and effector
molecules - more systemic mean faster there is simply a continuum of time courses of hypersensitivity categories, since there are
intermediate states of involving more mechanisms.
What is the biological role of the “invariant chain” (Ii, CD74) of MHC class II? filling the antigen binding groove in the secretory pathway (namely ER and Golgi apparatus) minimize the loading of self peptides on MHC II target and recycle MHCII to MHC II compartment (MIIC) the facilitation of exogenous peptide binding trimerization of de novo synthesized MHC II molecules.
Secreted immunoglobulin binds with its CDR loops to: virions and bacterial cells directly native unprocessed structural antigen (can be also discontinuous) T cells MHCI/MHCII with loaded peptide B cell to form surface BCR.
What is the physiological effector mechanism of antibodies? activation of effector leukocyte populations (NK cells, Macrophages) initiating killing or
phagocytosis after opsonizing antibodies bind to their Fc receptors initiate inflammation via the process of neutrophil degranulation neutralization of viruses and microbes - blocking the pathogen binding to the target cells opsonization - targeting complement and other bridging molecules (including antibodies) to the
target cell surface membrane Ig form transduce signal in B cell development.
Which Ig isotype or its form is characteristic for the mucosal humoral response? IgE monomeric IgA dimeric IgA IgM IgG.
In TCR and BCR receptor complexes, the ITAM motifs are present in: transmembrane adaptor proteins associated CD4/CD8 coreceptors in their intracellular tails CD3 (epsilon, gamma, delta, zeta chains) and CD79 (Ig-a and -b) associated signaling molecules, such as Src family kinases TCR and BCR itself.
Whis type of immune response is effective in tumor elimination? NK cell killing in both directions of missing-self and stress-induced self chronic inflammatory response T cell response - both CD4+ and CD8+ T cells cooperate macrophage phagocytosis antibody response.
Substances in neutrophil superoxide hydrogen peroxide HCl acid ...
What is an allo-transplant? is derived from a different individual, belonging to the same inbred strain of mouse is derived from a different individual, belonging to a same population (within a one species) is derived from a different species is derived from a different individual, belonging to a different inbred strain of mouse is derived from the same individual but a different body location.
Adhesion molecules of a cell of innate immunity C-lectin molecules integrines selectins TCR/BCR.
Signal transduction of TCR phophatases signales strongly, they first need to be turn off SHIP phospatases Src first wave, Syk second wave of phosporylation Syk first vawe, Src second wave of phosphorylation.
Valency number of ligands numeric count of overall binding sites of molecule.
Recognizing receptors of DAMPS and PAMPs on dendritic cells? PRR NLR TLR.
What are Th17 CD4+ NOT? Involved in the immune response against extracellular bacteria Involved in the immune response against intracellular pathogens Selected in secondary immune organs Produce IL17.
Which cell types belong to innate immune system? NK cell B cell mast cell neutrophil dendritic cell.
The signalling pathways/transcription factors driving inflammation include: FoxP3 IRF NF-kB NFAT PI3K.
Which lymphocyte cell types are selected by both positive selection (results in proliferation) AND
negative selection (results in apoptosis) during the development phase? Just the conventional alphabeta T cells undergo both selection processes in thymus. B cells
in bone marrow undergo only negative selection. NK cells throughout the body undergo
positive selection (so-called licensing). All T cells and B cells are cells of adaptive immune system and therefore must undergo both positive
selection (as a safe mechanism that TCR and BCR have been rearranged correctly) as well as
negative selection to prevent autoimmunity. NK cells do not undergo any selection process. All T cells undergo positive (so-called MHC restriction to recognize our own MHC molecules class I
and II) in thymic cortex and negative selection in thymic medulla to prevent autoimmunity. On the
other hand, B cells do not have to be selected during development, since these cells do mutate their
Ag-specific site in BCR all the time and are therefore eliminated in the lymph nodes at any time by the
control of T cell help. NK cells in the body undergo positive selection (licensing). Only a minor subset of T cells undergo both positive and negative selection in thymus in order to
minimize autoreactivity.B cells are selected in bone marrow in the process of negative selection,
though it has to repeat the selection later as well since their BCR mutates the Ag-binding site and can
become autoreactive at any time.NK cells do not need any selection, all of them do recognize our
own MHC-I molecules since all of them do express a combination of KIR receptors. The majority of T cells expressing alphabeta TCR undergo both positive and negative
selection, although some minor populations (so-called invariant T cells) escape the deletion
and are autoreactive in the periphery. B cells do not need to become positively selected since
there is no antigen presentation and these cells recognize native antigen. Negative selection
minimizes autoreactive clones. The same happens in the lymph nodes, where follicular
dendritic cells do not display auto-antigens but only those antigens, which leads to productive
response in the past forming Ag-specific antibodies and complement - in so-called immune
complexes. NK cells must be selected positively in order to check whether their KIR receptors
are capable to signal after binding to self-MHC molecules.
How do macrophages and natural killer cells select their targets (a friend or a foe)? various complement receptors are expressed on both cell types and the positive signal leads to target
cell killing (phagocytosis in case of a macrophage and perforin/granzyme in case of NK cell) since both macrophage and NK cell belong to the innate immunity, both recognize only complement
proteins as opsonins (complement is the major soluble product of innate immunity) when a common self-signature is missing (e.g. MHC molecule or CD47) both cell types are sitting in the tissues as resident cells and are capable of recognizing PAMPs and DAMPs via their pattern recognition receptors (PRR) - thus this signaling promotes inflammatory response leading to more efficient killing when a soluble product of innate or adaptive immunity is bound to the target cell.
How does the naive T cell gets to lymph nodes on the way from bone narrow? through thymus then entering peripheral tissues via venous capillaries and through lymfatics to the
lymph nodes through thymus (positive selection), exit to peripheral tissues and later after returning to thymus
(negative selection), all through blood circulation directly via the lymphatic system to the lymph nodes through thymus and spleen via lymphatics to the lymph nodes through thymus and systemic blood circulation to the lymph nodes.
How the naive B cell gets activated for clonal expansion and antibody production? In any scenario, there must be a 2-step signal in order to add the danger information to the
native antigen-BCR crosslinking. There is just BCR crosslinking needed in order to activate a B cell to clonal expansion and
differentiation to plasma cell producing antibodies. Since B cell is part of adaptive immunity, it is solely dependent on the antigen stimulation, in both T
cell-dependent and -independent fashion. For T cell-dependent antigens, a costimulation from activated T-cell reflects the danger sensed
by professional APC and for T cell-independent antigens there are PRR on the B cell triggered
by danger signals. During the initial stage of activation, a B cell needs to balance the costimulation via its Fc receptors
(inhibition of excessive response) and complement receptors (activation of acute response) in order
to reflect the previous immune experience.
Which is the major reactive species molecule in neutrophils? hydrogen peroxide hypochlorous acid/hypochlorite nitrogen superradical peroxynitrite oxygen superradical.
Name TCR coreceptors and their recognized ligands on APC. CD4/CD40, CD8/CD80 CD40L/CD40 CD4/MHC-II CD8/MHC-I CD4/CD80, CD8/CD40.
What is the TRUE statement when comparing three activation pathways of complement cascade? the mannose-binding lectin inducing the lectin pathway does NOT bind to the carbohydrates
found on healthy human cells and tissues the alternative pathway is spontaneous (random) based on very short half-life of its C3b
component compared to both lectin and classical pathways (dependent on MBL and antibody
targeting, respectively) the alternative pathway is evolutionary older compared to the lectin and classical pathways the lectin but NOT alternative NOR classical pathways is independent of serine protease activity in
the cascade propagation the alternative but NOT the lectin pathway can destroy our own cells.
Which cytokine(s) stimulate the differentiation of Th2 cells? IFN-gamma IL-3 IL-12 IL-2 IL-4.
Can B cells be activated without T cell help? If so, why is T cell-independent activation of B cells so
important in defending us against certain pathogens? T cell help is only necessary for the class switch of Ig isotypes which is related to the function of the particular isotype, not the Ag-specificity. B cells do need a T cell help - a costimulatory signal - only during the primary response to make it faster and clear the pathogens from the body faster. Without the T cell help, B cells would act slower but still efficiently enough. There is only a quantitative difference between help/no help scenario. Via massive crosslinking of BCR using polyvalent ligands - here it is clonal, yet with no need
for T cell help in the form of CD40-CD40L interaction. Via crosslinking of another receptors (not BCR), often PRR - leading to polyclonal response
(not Ag-specific). This is mostly IgM isotype and carbohydrate-specific, recognizing patterns
of danger. T cell help is NOT essential for the majority of B cells since their BCR can mutate its Ag-recognition CDR loops, and therefore it makes no sense to provide help in this ever-changing situation.
What does passive immunization mean? immunization delivered via digestive tract – also called oral immunization immunization using a needle penetrating through skin and delivering the vaccine directly into body immunization using immortalized bacterial vaccine immunization using immortalized virus-derived vaccine immunization using immunoglobulins - e.g. previously generated specific antibodies.
Which approaches are used before/during/after organ transplantation in clinics? immunosuppression using drugs targeting NFAT signaling pathway in T cells immunosuppression using drugs targeting mutations in TAP transporters host/donor HLA match testing search for the best match between host and donor in their TCR-repertoire KIR/MHC mismatch for assessment of the NK cell reactivity.
Which mechanisms are specific for rapid innate immune response against pathogens? complement and coagulation cascades antibody production cytokine production ADCC and missing -self targeted cellular cytotoxicity phagocytosis.
After their development in the thymus naive T cells... exit to the blood stream and migrate to secondary lymphoid organs, where they become primed by
follicular B cells in Germinal centers exit to the lymphatics through which they migrate either to secondary lymphoid organs or sites of
infection, where they become activated by antigen presenting cells exit to the blood stream and migrate to secondary lymphoid organs, where they become
primed by dendritic cells exit to the blood stream where they follow pro-inflammatory signals leading them to the sites of
infection, where they become activated by dendritic cells, presenting processed foreign antigens.
Differentiation of naive T cells into CD4 Th2 subset is mainly driven by: IL-4 stimulation TCR stimulation TGFbeta stimulation IFNgamma stimulation.
Initiating enzymes of signaling cascades are kinases and phosphatases. Which ones are critical for
initiating lymphocyte signaling cascades in general? SHP-1, SHP-2 inhibitory phosphatases must be first inactived in order to allow Src kinases to
phosphorylate Syk kinases which then phosphorylate downstream substrates - adaptor proteins. Src family kinases phosphorylate ITAM motives, which serve as docking platforms for Syk
family kinases. Since phosphatases are more active that kinases in the basal state these must be switched off first,
and then both kinase families (Src, Syk) become active at the same time. Syk family kinases in the first wave and Src family kinases in the second wave of phosphorylation Src family kinases in the first wave and Syk family kinases in the second wave of phosphorylation.
In which cellular compartment/organelle does the peptide bind to MHC class I molecule? secretory vesicle of endosomal origin phagolysosome endoplasmic reticulum positive for TAP transporters Golgi apparatus cytoplasm with proteasome - cleaving antigens to short peptides.
Which structural feature is typical for T-independent antigens? repetitive structural motifs small size (less than 5kDa) and a globular shape structures that bind to other receptors than BCR itself large and stable polymeric structures in the case of a protein molecule - its glycosylation or other posttranslational modifications.
Adaptive immunity is a mode of function where: all lymphocyte cell lineages can adopt to any new mutation occurring in the body antigen specific memory is generated immune cells are clonally regulated evolutionary young diversification of immunoreceptors forms the base for the recognition of... immune cells can clear the pathogen efficiently and completely.
What is the major difference between the cognate receptors of the innate (for danger) and adaptive... innate receptors are more polymorphic innate receptors show population distribution among cells innate receptors are much less specific adaptive receptors show clonal distribution among cells adaptive receptors show diversity of > 10 ~ 14.
What is the mechanism of particle engulfment and destruction? transcytosis phagocytosis endocytosis micropinocytosis exocytosis.
Which types of ligands do alpha/beta T cells generally recognize using TCR? highly hydrophobic substances derived from bacterial cell walls posttranslationally modified peptides NK cells must be selected positively in order to check whether their KIR receptors are capable
to... B cells do not need to become positively selected since there is no antigen presentation and
these... happens in the lymph nodes, where follicular dendritic cells do not display autoantigens
but only... complement - in so-called immune complexes. The majority of T cells expressing alphabeta TCR undergo both positive and negative
selection... autoreactive in the periphery.
Which molecules belong to leukocyte adhesion receptors: complement receptors TLR Selectins Integrins C-type lectins.
Which cell type belongs to lymphoid lineage? B cell NK cell NKT cell T cell M cell.
Which cell type/mode of phagocytosis is true? dendritic cells phagocytose moving objects macrophages phagocytose stable objects dendritic cells phagocytose stable objects neutrophils phagocytose stable objects macrophages phagocytose moving objects.
Higher diversity within the V domain of BCR and TCR occurs at: the contact site with the pMHC or antigen CDR3 randomly generated variation throughout the V domain after VDJ recombination heavy chain compared to light chain of antibody molecule all CDRs – all are diversified more compared to the rest of V domain.
What is beta2-microglobulin? protein fold involved in the formation of the antigenic binding part of the antibody inhibitor of alpha2-macroglobulin a molecule produced into serum as one of the proteins of acute phase during inflammation a protein fold involved in the formation of the peptide-loading groove of MHC molecules a molecule forming non-covalent dimers with classical and some non-classical MHC-I molecules.
Helper T cells are polarized into the following populations: Th1 Th2 Th17 Treg.
Class switch recombination (CSR) is responsible for some Ig (C- domain usage). Which ones? IgG IgA IgE IgM.
How to treat an acute hypersensitivity reaction of type I? epinephrine beta-sympatomimetics surgically - open trachea high i.v. dose of Ca2+.
What the hygiene hypothesis means and how does it shape the immune system? lack of natural infections low Th1 polarization in the early childhood lack of PAMP availability in childhood leads to hyper-reactivity in the adulthood.
Which is the most frequent target molecule of immune intervention in clinical practice? TNF.
Migration of immune cells is regulated by: Chemokines adhesion molecules.
Why there is only one gene product of TCR or BCR expressed in a single cell? due to allelic exclusion (recombination from a single allele) controlled by epigenetic regulation There is no strict rule single cell = single receptor, it is leaky. Therefore, in some cells there are more
alleles expressed resulting in more than 1 receptor / cell.
Which Ig classes (isotypes) are developmentally regulated by alternative mRNA splicing? IgM IgD IgE IgA.
Which processes are initiated by the action of activation-induced deaminase (AID)? class switch recombination somatic hypermutation gene conversion.
At which stage of selection is the TCR tested for the recognition of self MHC recognition? positive selection negative selection.
Which somatic processes are responsible for antigen receptor diversification in order to bind all possible
antigens? Recombination gene conversion nucleotide addition somatic hypermutation.
adjuvant is: any trigger that can initiate and later boost the immune response PAMPs or DAMPs stimulating PRR receptors PAMPs or DAMPs stimulating PRR receptors
- any compound which is necessary to increase the quantity of already initiated immune response (boosting effect) - remember the difference of depot and PRR-stimulating effects.
the mobile sentinel cell type activated after tissue damage, capturing and distributing Ag from the damaged site to the adaptive immune cell is: dendritic cell.
select the particular functional IR process responsible for the full tissue homeostasis = from start to the
contraction of the IR: resistance costimulation wound repair tolerance cell death.
which cell death type is triggering immune response and why? necrosis, bcs it is releasing the cytoplasm material outside of the cell pyroptosis and pyronecrosis, bcs it releases pyrogens (cytokines to promote inflammation) in a large excess apoptosis.
is the immune privileged organ devoid of the IS components? no, the critical organs for developement (testes, decidua) or sensors (eyes, brain) can mount a
different type (class) of IR no, but the immune cells present are of special phenotype, usually the suppresors.
what is the target category to be recognized by NK cells? missing self stress-induced self infectious non-self.
which enzymes are balancing each other during the immune cell activation and signaling? kinases / phosphatases.
antigenic protein structure recognized by BCR can be: an epitope on the naive surface of the folded protein structure a continuous linear sequence of a few aminoacids a discontinuous epitope composed of a few independent fragments of a polypeptide polymeric non-processed structure effectively crosslinking BCR.
Allograft Transplant from the same species, different individuals Transplant from the same inbred strain Transplant from different species Transplant from genetically identical individuals.
Which cytokines do NK and NTK cells produse? IL10 IL2 INF gamma TGF beta IL4/IL13.
What is graft versus leukemia reactivity based on? Non-licensed donor NK cells kill leucemic cells via their activating KIRs Licensed donor NK cells kill host leukemic cells via their inhibitory KIRs Donor T cells recognize residual host leukemic cells as these express allo peptide MHC molecules and kill them.
What is a superantigen and the result of its presence in the body? an antigen stimulating TCR with very high efficiency solube bacterial enterotoxin stimulating many clones of T cells leading to the exhaustion of the immune response a viral product crosslinking TCR V beta domain with MHC molecule independent of a peptide.
What is the most important feature of T-independent antigens for B cells? polymeric structure of Ag and other receptors involvement than just BCR multivalent interaction of BCR with Ag cleaved antigen via Ag processing native structure of Ag immobilization of an antigen in the form of an immune complex (with antibody and complement).
What is the antigen binding site of an immunoglobulin? V domain Fab fragment CDR (complementarity determining region) loops Fc fragment paratope.
Which pair of receptors is essential for T cell costimulation? CD80(CD86)/CD28 PDL1/PD1 CD80(CD86)/CTLA4 CD40L/CD40 CD4(CD8)/MHC-II(MHC-I).
Which signaling pathways are central to T cell activation? STAT NF-kB NFAT PI3K MAPK.
Migration of immune cells is regulated by: hormones cytokines adhesion molecules ion gradient chemokines.
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