Test Bank for Kuby
Immunology Covid-19
Digital Update, 8th
Edition by Jenni Punt,
Sharon Stranford, Patricia
Jones, Judy Owen.pdf
The first cells to exit the bloodstream and enter infected tissue in large numbers are
typically:
A. Naive CD8 T cells
B. Neutrophils
C. Plasma cells
D. NK T cells
Answer: B. Rationale: Neutrophils are rapid responders and dominate early acute
inflammation.
A pathogen that primarily replicates in the cytosol will be presented to CD8 T cells
via:
A. MHC I after proteasomal processing
B. MHC II after endosomal processing
C. CD1d after lipid loading
D. FcRn after transcytosis
Answer: A. Rationale: Cytosolic proteins are degraded by the proteasome; peptides
enter ER via TAP to load MHC I.
,Which PRR–ligand pair is correctly matched?
A. TLR3—dsRNA
B. TLR4—unmethylated CpG DNA
C. TLR5—lipoteichoic acid
D. NOD2—viral hemagglutinin
Answer: A. Rationale: TLR3 detects dsRNA; TLR4 detects LPS; TLR5 detects flagellin;
NOD2 senses muramyl dipeptide.
An isotype switch from IgM to IgG requires:
A. AID and T cell help (CD40–CD40L)
B. TLR signaling only
C. RAG1/2 activity in mature B cells
D. Fas–FasL signaling only
Answer: A. Rationale: Class switch recombination uses AID and requires T cell–
dependent signals.
Affinity maturation occurs primarily in:
A. Thymic cortex
B. Bone marrow
C. Germinal centers
D. Red pulp of spleen
Answer: C. Rationale: Somatic hypermutation and selection in GCs increase antibody
affinity.
A key difference between BCR and TCR antigen recognition is that BCRs:
A. Recognize only peptide fragments
B. Require antigen processing by APCs
C. Can bind native, conformational epitopes
D. Are MHC-restricted
Answer: C. Rationale: BCRs bind native antigen; TCRs recognize peptides presented
by MHC.
,The classical complement pathway is most efficiently triggered by:
A. C3 tick-over
B. Mannose residues on pathogens
C. Antigen–IgM/IgG immune complexes
D. Properdin on bacterial surfaces
Answer: C. Rationale: C1q binds Fc of IgM or clustered IgG in immune complexes.
A patient lacks C3. Which function is most compromised?
A. Opsonization for phagocytosis
B. IFN-α/β production
C. VDJ recombination
D. MHC I expression
Answer: A. Rationale: C3b is the principal opsonin; C3 deficiency causes recurrent
pyogenic infections.
Cross-presentation allows:
A. B cells to present lipid antigens on CD1
B. DCs to present exogenous antigens on MHC I
C. Macrophages to present cytosolic antigens on MHC II
D. NK cells to present antigen to T cells
Answer: B. Rationale: Specialized DCs can load exogenous antigens onto MHC I to
prime CD8 T cells.
SARS-CoV-2 entry into host cells primarily depends on:
A. Spike–ACE2 binding and TMPRSS2 priming
B. Hemagglutinin–sialic acid binding
C. GP120–CD4 binding
D. NS1-mediated membrane fusion
Answer: A. Rationale: Spike engages ACE2; proteases like TMPRSS2 facilitate fusion.
, The dominant antibody isotype in upper respiratory mucosa post-infection or
intranasal vaccination is:
A. IgM
B. IgE
C. IgA (dimeric/secretory)
D. IgD
Answer: C. Rationale: Secretory IgA is specialized for mucosal surfaces.
Adenoviral-vector COVID-19 vaccines most directly induce:
A. Only humoral responses
B. Robust CD8 and CD4 T cell responses plus antibodies
C. T-independent B cell responses
D. Tolerance via Tregs
Answer: B. Rationale: Vectors drive antigen expression in host cells → MHC I & II
presentation and antibody production.
A cytokine central to Tfh differentiation and GC help is:
A. IL-2
B. IL-4
C. IL-21
D. IFN-γ
Answer: C. Rationale: IL-21 supports B cell help and GC reactions.
Which scenario best illustrates “original antigenic sin” (immune imprinting)?
A. First exposure gives the strongest response
B. Later variant exposure recalls memory to ancestral epitopes, potentially limiting
breadth
C. IgM responses dominate all subsequent infections
D. T cells ignore mutated epitopes
Answer: B. Rationale: Memory biases responses toward initial epitopes even when
variants differ.
Immunology Covid-19
Digital Update, 8th
Edition by Jenni Punt,
Sharon Stranford, Patricia
Jones, Judy Owen.pdf
The first cells to exit the bloodstream and enter infected tissue in large numbers are
typically:
A. Naive CD8 T cells
B. Neutrophils
C. Plasma cells
D. NK T cells
Answer: B. Rationale: Neutrophils are rapid responders and dominate early acute
inflammation.
A pathogen that primarily replicates in the cytosol will be presented to CD8 T cells
via:
A. MHC I after proteasomal processing
B. MHC II after endosomal processing
C. CD1d after lipid loading
D. FcRn after transcytosis
Answer: A. Rationale: Cytosolic proteins are degraded by the proteasome; peptides
enter ER via TAP to load MHC I.
,Which PRR–ligand pair is correctly matched?
A. TLR3—dsRNA
B. TLR4—unmethylated CpG DNA
C. TLR5—lipoteichoic acid
D. NOD2—viral hemagglutinin
Answer: A. Rationale: TLR3 detects dsRNA; TLR4 detects LPS; TLR5 detects flagellin;
NOD2 senses muramyl dipeptide.
An isotype switch from IgM to IgG requires:
A. AID and T cell help (CD40–CD40L)
B. TLR signaling only
C. RAG1/2 activity in mature B cells
D. Fas–FasL signaling only
Answer: A. Rationale: Class switch recombination uses AID and requires T cell–
dependent signals.
Affinity maturation occurs primarily in:
A. Thymic cortex
B. Bone marrow
C. Germinal centers
D. Red pulp of spleen
Answer: C. Rationale: Somatic hypermutation and selection in GCs increase antibody
affinity.
A key difference between BCR and TCR antigen recognition is that BCRs:
A. Recognize only peptide fragments
B. Require antigen processing by APCs
C. Can bind native, conformational epitopes
D. Are MHC-restricted
Answer: C. Rationale: BCRs bind native antigen; TCRs recognize peptides presented
by MHC.
,The classical complement pathway is most efficiently triggered by:
A. C3 tick-over
B. Mannose residues on pathogens
C. Antigen–IgM/IgG immune complexes
D. Properdin on bacterial surfaces
Answer: C. Rationale: C1q binds Fc of IgM or clustered IgG in immune complexes.
A patient lacks C3. Which function is most compromised?
A. Opsonization for phagocytosis
B. IFN-α/β production
C. VDJ recombination
D. MHC I expression
Answer: A. Rationale: C3b is the principal opsonin; C3 deficiency causes recurrent
pyogenic infections.
Cross-presentation allows:
A. B cells to present lipid antigens on CD1
B. DCs to present exogenous antigens on MHC I
C. Macrophages to present cytosolic antigens on MHC II
D. NK cells to present antigen to T cells
Answer: B. Rationale: Specialized DCs can load exogenous antigens onto MHC I to
prime CD8 T cells.
SARS-CoV-2 entry into host cells primarily depends on:
A. Spike–ACE2 binding and TMPRSS2 priming
B. Hemagglutinin–sialic acid binding
C. GP120–CD4 binding
D. NS1-mediated membrane fusion
Answer: A. Rationale: Spike engages ACE2; proteases like TMPRSS2 facilitate fusion.
, The dominant antibody isotype in upper respiratory mucosa post-infection or
intranasal vaccination is:
A. IgM
B. IgE
C. IgA (dimeric/secretory)
D. IgD
Answer: C. Rationale: Secretory IgA is specialized for mucosal surfaces.
Adenoviral-vector COVID-19 vaccines most directly induce:
A. Only humoral responses
B. Robust CD8 and CD4 T cell responses plus antibodies
C. T-independent B cell responses
D. Tolerance via Tregs
Answer: B. Rationale: Vectors drive antigen expression in host cells → MHC I & II
presentation and antibody production.
A cytokine central to Tfh differentiation and GC help is:
A. IL-2
B. IL-4
C. IL-21
D. IFN-γ
Answer: C. Rationale: IL-21 supports B cell help and GC reactions.
Which scenario best illustrates “original antigenic sin” (immune imprinting)?
A. First exposure gives the strongest response
B. Later variant exposure recalls memory to ancestral epitopes, potentially limiting
breadth
C. IgM responses dominate all subsequent infections
D. T cells ignore mutated epitopes
Answer: B. Rationale: Memory biases responses toward initial epitopes even when
variants differ.
