Immuno Set 2 (Innate Immunity) Flashcards
Which of the following DOES NOT accurately describe the complement components?
A. soluble proteins
B. made by the spleen
C. located in extracellular spaces
D. some function as proteases once activated
E. activated by a cascade of enzymatic reactions
B. made by the spleen
Which of the following TLRs do not use a signal transduction cascade involving MyD88?
A. TLR1:TLR2 B. TLR3 C. TLR4 D. TLR2:TLR6 E. TRL7
B. TLR3
Which of the following is an acute-phase protein that activates complement?
A. TNF-α B. mannose-binding lectin C. fibrinogen D. LFA-1 E. CXCL8
B. mannose-binding lectin
Which of the following is a receptor on macrophages that is specific for PAMPs?
A. Receptor for C5a B. Fc receptor C. Complement receptor D. Mannose receptor E. ICAM-1
D. Mannose receptor
A 4-year-old girl stepped on a rusty nail in her backyard. Two days later, she is taken to the pediatrician because her heel is painful, red, and swollen and is warm to the touch. All of the following are mechanisms of innate immunity that may be protecting the patient against pathogenic microbes in the heel wound EXCEPT:
A. Epithelial barrier function of the skin of her foot
B. Complement proteins present in the interstitial fluids
C. Circulating anti-tetanus toxin antibodies
D. Circulating neutrophils migrating to the site of the wound
E. Soluble cytokines that induce a local inflammatory response
C. Circulating anti-tetanus toxin antibodies
Which of the following molecules is a component of NK cell granules and is important in killing of target cells?
A. P-selectin
B. Major basic protein
C. C9 complement component D. ICAM-1
E. Perforin
E. Perforin
A common strategy by which microbes survive their host’s immune responses involves changing the structures of the molecules they produce so that they are no longer recognized by the host’s immune system. This strategy, called an antigenic variation, is most likely to allow evasion of which type of immune recognition?
A. Toll-like receptor-dependent recognition of microbes by cells of the innate immune system
B. Antibody recognition of microbial cell surface molecules
C. Mannose receptor-dependent recognition of microbes by cells of the innate immune system
D. Natural killer cell inhibitory receptor recognition of class I MHC molecules on infected cells
E. T cell receptor recognition of microbial cell wall lipid antigens
B. Antibody recognition of microbial cell surface molecules
Which of the following is NOT part of the innate immune response to extracellular bacteria?
A. Alternative pathway of complement activation
B. Lectin pathway of complement activation
C. Activation of phagocytosis by Toll-like receptors
D. Natural killer cell activation
E. Inflammation
D. Natural killer cell activation
All of the following are known mechanisms by which extracellular bacteria evade the immune system EXCEPT:
A. Capsules prevent phagocytosis B. Inhibition of class I MHC expression C. Genetic variation of surface antigens D. Inhibition of complement activation E. Neutralization of reactive oxygen intermediates
B. Inhibition of class I MHC expression
Which of the following is a feature of Natural Killer (NK) cells?
A. They express antigen receptors that directly bind antigens on the surface of microbes
B. They are activated by recognizing microbial peptides bound to host class I MHC molecules
C. They kill virally infected cells by a perforin/granzyme dependent mechanism
D. Upon activation, they secrete abundant IL-4
E. They secrete natural IgM antibodies
C. They kill virally infected cells by a perforin/granzyme dependent mechanism
All of the following molecules are opsonins that facilitate efficient phagocytosis of microbes by neutrophils and macrophages EXCEPT:
A. C3b B. C5a C. C-reactive protein D. IgG E. Mannose-binding lectin
B. C5a
Toll like receptors (TLRs) located in endosomal membranes of cells recognize which of the following?
A. Nucleic acids
B. Bacterial cell wall lipoteichoic acid
C. Bacterial cell wall lipopolysaccharide
D. Uric acid crystals
E. Peptides containing N-formylmethionyl residues
A. Nucleic acids
Which of the following statements about the recognition receptors of the innate immune system, such as Toll like receptors, is correct?
A. They are encoded by genes produced by somatic recombination of gene segments that are separated in inherited germline DNA
B. Each clone of macrophages express a unique set of these receptors that differs in specificity from those receptors on all other clones of macrophages
C. They recognize pathogen associated molecular patterns, such as viral nucleic acids, bacterial cell wall constituents, and terminal mannose residues.
D. They function to neutralize microbes, but do not initiate signal transduction pathways that activate cells.
E. They undergo somatic mutation and affinity maturation in response to microbial antigens.
C. They recognize pathogen associated molecular patterns, such as viral nucleic acids, bacterial cell wall constituents, and terminal mannose residues.
Which of the following IS NOT a function of the innate immune system?
A. Rapidly respond to microbial infections by promoting acute inflammation
B. Respond to viral infections by inducing the expression of type I interferons
C. Respond to microbial infections by inducing expression of T cell costimulators on antigen presenting cells
D. Respond to damaged and dying host cells by inducing acute inflammation
E. Respond to microbial infections by inducing a state of long lived memory that prevents repeat infections by the same microbe
E. Respond to microbial infections by inducing a state of long lived memory that
prevents repeat infections by the same microbe
A child with a mutation in the gene encoding one of the polypeptide chains of the integrin LFA-1 suffers from recurrent serious bacterial and fungal infections, and the sites of infection contain
few inflammatory leukocytes. Which of the following accurately describes the required function
of host defense that is missing in this child?
A. LFA-1 on endothelial cells binds to carbohydrate ligands on neutrophils and monocytes, causing these leukocytes to stably arrest on the endothelial surface.
B. LFA-1 on neutrophils and monocytes binds to ICAM-1 on endothelial cells causing the leukocytes to stably arrest on the endothelial surface.
C. LFA-1 on leukocytes binds to chemokines in tissues, which direct leukocytes to migrate into sites of infection
D. LFA-1 on endothelial cells binds to VCAM-1 on T cells, which supports migration of activated T cells into tissues
E. LFA-1 on neutrophils binds to ICAM-1 on bacterial cell walls, which supports phagocytosis of the bacteria.
B. LFA-1 on neutrophils and monocytes binds to ICAM-1 on endothelial cells causing the leukocytes to stably arrest on the endothelial surface.