Ch13 Flashcards
Which cells are specialized interferon-producing cells that can produce high levels of Type I IFN without becoming infected?
a) B cells
b) Plasmacytoid dendritic cells (pDCs)
c) Natural killer (NK) cells
d) Macrophages
B
Type I IFN production is triggered by the recognition of what?
a) Host cellular components
b) Bacterial patterns
c) Molecular patterns characteristic of viruses
d) Fungal components
C
What do cytoplasmic PRRs such as RIG-I detect?
a) Bacterial proteins
b) Viral nucleic acids in the cytoplasm
c) Host DNA in the nucleus
d) Fungal cell walls
B
What is the immediate cellular response when cytoplasmic PRRs detect viral nucleic acids?
a) Production of antibodies
b) Activation of transcription factors
c) Release of histamines
d) Initiation of phagocytosis
B
What is the ultimate result of the activation of transcription factors by cytoplasmic PRRs in virally-infected cells?
a) Inhibition of viral replication
b) Transcription of interferon (IFN) genes
c) Cell apoptosis
d) Production of cytokines
B
How do plasmacytoid dendritic cells (pDCs) respond to the presence of a virus without becoming infected?
a) They produce antibodies
b) They up-regulate Type I IFN production
c) They phagocytize the virus
d) They produce complement proteins
B
When are natural killer (NK) cells typically activated following a viral infection?
a) Within a few hours
b) Within 1 day
c) Within 2 days
d) Within a week
C
What is the primary function of NK cells in response to a viral infection?
a) Producing antibodies
b) Presenting antigens
c) Being cytotoxic for virally-infected cells
d) Producing mucus
C
Which of the following cell types can detect the presence of a virus and up-regulate Type I IFN production without becoming infected?
a) NK cells
b) Macrophages
c) Plasmacytoid dendritic cells (pDCs)
d) Eosinophils
C
When does the adaptive immune response typically begin after the activation of the innate immune response?
a) Immediately
b) A few hours later
c) A few days later
d) A few weeks later
C
Which type of T cells start to appear at the site of infection around 4 days after the initiation of viral expansion?
a) CD4+ T cells
b) CD8+ T cells (CTL)
c) B cells
d) NK cells
B
What is the primary role of CD8+ T (CTL) cells in viral infections?
a) Producing antibodies
b) Presenting antigens
c) Directly killing infected cells
d) Producing cytokines
C
When are antibodies typically induced in response to a viral infection?
a) Around day 2
b) Around day 4
c) Around day 6 or 7
d) Around day 10
C
How do antibodies contribute to recovery from a viral infection?
a) By activating macrophages
b) By neutralizing the infectivity of viruses
c) By enhancing phagocytosis
d) By producing cytokines
B
What is an important factor in the prevention of reinfection by a virus?
a) Presence of memory T cells
b) Presence of virus-neutralizing antibodies in the circulation
c) Activation of NK cells
d) Production of cytokines
B
