Immediate
C-type lectins are so called because of the role of _____ in facilitating receptor:ligand interactions.
a. carbohydrate
b. CR1
c. calcium
d. chemokines
e. caspases.
c. calcium
_____ is a soluble protein. (Select all that apply.)
a. TLR4
b. CD14
c. lipopolysaccharide-binding protein (LBP)
d. CXCR1
e. mannose-binding lectin.
c. lipopolysaccharide-binding protein (LBP)
e. mannose-binding lectin
Which of the following is an acute-phase protein that enhances complement fixation?
a. TNF-\alpha
b. mannose-binding lectin
c. fibrinogen
d. LFA-1
e. CXCL8.
b. TNF-/alpha
The name given to a fully activated and differentiated B cell that secretes antibody is
a. T cell
b. antigen-presenting cell
c. hematopoietic cell
d. secretory cell
e. plasma cell.
e. plasma cell
Which of the three complement pathways becomes activated soonest after an initial infection?
a. the classical pathway
b. the lectin pathway
c. the alternative pathway.
c. the alternative pathway
Lectins recognize microbial _____.
a. phosphate-containing lipoteichoic acids
b. nucleic acids
c. carbohydrates
d. flagellin
e. sulfated polysaccharides.
c. carbohydrates
Which of the following properties is common to macrophages and neutrophils in an uninfected individual?
a. life-span
b. anatomical location
c. ability to phagocytose
d. morphology
e. formation of pus.
c. ability to phagocytose
Which of the following best describes an endogenous pyrogen?
a. cytokines made by pathogens that decrease body temperature
b. pathogen products that decrease body temperature
c. pathogen products that increase body temperature
d. cytokines made by the host that decrease body temperature
e. cytokines made by the host that increase body temperature.
e. cytokines made by the host that increase body temperature
_____, _____, and _____ are the three most abundant antibodies in blood:
a. IgA, IgD, and IgE
b. IgA, IgE, and IgG
c. IgA, IgG, and IgM
d. IgE, IgG, and IgM
e. IgD, IgE, and IgM.
c. IgA, IgG and IgM
The plasma proteins that counteract the activity of factor P by inactivating C3 convertase through the cleavage of C3b are _____.
a. factor B and factor H
b. factor H and factor I
c. factor B and factor I
d. decay-accelerating factor and factor H
e. decay-accelerating factor and membrane cofactor protein.
b. factor H and factor I
Scavenger receptor SR-B recognizes _____.
a. lipopolysaccharides
b. teichoic acid
c. filamentous hemagglutinin
d. CpG-rich bacterial DNA
e. lipids.
e. lipids
Which of the following does not describe a safety mechanism to ensure that only infected cells are attacked by NK cells?
a. The default state is one of active inhibition, which must be overcome by activating signals before killing occurs.
b. Intimate contact with target cells is required.
c. No single receptor–ligand interaction induces cytotoxicity, but instead many combinations of receptor–ligand interactions influence the decision to kill or not to kill a target cell.
d. All of the above are safety are safety features that have evolved to prevent NK cells from attacking healthy cells.
d. all of the above are safety are safety features that have evolved to prevent NK cells from attacking healthy cells
Which of the following adaptor proteins participates in the activation pathway induced through either TLR3 or TLR4 that culminates in the synthesis of type I interferons?
a. C-reactive protein
b. MyD88
c. LPS-binding protein
d. TRIF
e. NF\kappaB.
d. TRIF
Which one of the following features renders all IgG antibodies less susceptible to proteolysis than the other antibody classes?
a. length of the hinge region
b. ability to exchange chains with other IgG antibodies
c. presence of additional disulfide bonds
d. capacity to activate complement
e. degree of accessibility for binding to C1.
c. presence of additional disulfide bonds
_____ are soluble complement fragments that mediate localized and systemic inflammatory responses.
a. cryptdins
b. defensins
c. anaphylatoxins
d. selectins
e. C-reactive proteins.
c. anaphylatoxins
Macrophages bear on their surface receptors for all of the following except _____. (Select all that apply).
a. mannose
b. glucans
c. C3b
d. muramyl dipeptide
e. lipopolysaccharide
f. lipoteichoic acid
g. CpG-rich bacterial DNA.
d. muramyl dipeptide
g. CpG-rich bacterial DNA
Which of the following is not a characteristic of C-reactive protein?
a. acts as an opsonin by binding to phosphorylcholine of pathogens
b. synthesized by spleen
c. induced by elevated IL-6 levels
d. a member of the pentraxin family
e. triggers the classical pathway of complement activation.
b. synthesized by the spleen
Which of the following does not describe a feature observed when a target cell is induced to commit apoptosis by an NK cell?
a. DNA fragmentation by target cell nucleases
b. target cell shrinkage
c. shedding of membrane-enclosed vesicles by the target cell
d. chromatin extrusion in the form of decondensed DNA by the target cell
e. macrophage disposal of apoptotic remains of the target cell.
d. chromatin extrusion in the form of decondensed DNA by the target cell
In contrast with leader peptides and the C regions, the V regions in immunoglobulin heavy-chain genes
a. encode hydrophobic amino acids that anchor the immunoglobulin chains to B-cell membranes
b. comprise the smallest number of gene segments in the human immunoglobulin loci
c. are composed of V, D, and J gene segments that must undergo gene rearrangement to generate a transcribable exon
d. do not undergo somatic hypermutation
e. are not subject to allelic exclusion.
c. are composed of V, D, and J gene segments that must undergo gene rearrangement to generate a transcribable exon
Damage to tissues triggers a cascade of plasma proteins involving bradykinin and is known as _____.
a. the alternative pathway of complement
b. the coagulation system
c. the kinin system
d. receptor-mediated endocytosis
e. the acute-phase response.
c. the kinin system
_____ help to prevent systemic bacterial dissemination by producing chromatin structures loaded with antimicrobial substances.
a. Inflammasomes
b. Neutrophil extracellular traps
c. RIG-1-like helicases
d. Granulomas
e. Plasmacytoid dendritic cells.
b. neutrophil extracellular traps
On the basis of laboratory experiments, a possible scenario for the activation of an adaptive immune response would involve _____ within an infected tissue. (Select all that apply.)
a. a balanced number of myeloid dendritic cells and NK cells
b. an abundance of NK cells compared with myeloid dendritic cells
c. a shortage of NK cells compared with myeloid dendritic cells
d. migration of myeloid dendritic cells to secondary lymphoid tissue
e. migration of NK cells to secondary lymphoid tissue.
c. shortage of NK cells compared with myeloid dendritic cells
d. migration of myeloid dendritic cells to secondary lymphoid tissue
All of the following are true of MyD88 except _____.
a. It binds to the TIR domains of all Toll-like receptors except TLR3.
b. It binds to IRAK4, a protein kinase, causing the kinase to phosphorylate itself.
c. It is an adaptor protein with similar function to TRIF.
d. A genetic deficiency of MyD88 causes the disease X-linked ectodermal dysplasia and immunodeficiency.
d. a genetic deficiency of MyD88 causes the disease X-linked ectodermal dysplasia and immunodeficiency
Neutralizing antibodies
a. interfere with antigen degradation
b. facilitate uptake of antigen through Fc regions
c. stimulate complement activation
d. inhibit interaction of antigen with human cell surfaces
e. sensitize mast cells and basophils.
d. inhibit interaction of antigen with human cell surfaces
Which of the following does not describe defensins?
a. highly conserved with few variants
b. contain a large proportion of arginine residues
c. contain three intra-chain disulfide bonds
d. amphipathic, with hydrophobic and hydrophilic regions
e. disrupt pathogen membranes by penetrating them and disrupting their integrity.
a. highly conserved with few variants