DD- HOST RESPONSE

Question 1

Virus Structure/Function

Answer 1

Gene expression. Decode the information in the genome (make mRNA and translate proteins)

Replication. Make more copies of the genome

Assembly. Package the new genomes in infectious particles

Question 2

All RNA viruses encode an:

Answer 2

RNA-dependent RNA polymerase RdRp

Question 3

Seven Classes of Viral Genomes and Replication schemes

Answer 3

dsDNA
Gapped circular DNA
ssDNA
dsRNA
ss(+)RNA
ss(+)RNA with DNA intermediate
ss(-)RNA

Question 4

Production of virus particles depends on host cell machinery:
Assembly

Answer 4

• cellular proteins that catalyze or assist the folding of individual protein molecules
• cell transport systems move viral proteins and nucleic acids to sites of assembly
• Membrane proteins enter the secretory pathway
• Nuclear proteins use nuclear import machinery
• Subunits move on the cytoskeleton using cellular motors

Question 5

For helical nucleocapsids: Viral genomic RNA is generally _______during synthesis of the genome.

Answer 5

coated with nucleocapsid protein

Question 6

For icosahedral capsids Viral genomic RNA is generally _______during synthesis of the genome.

Answer 6

The capsid assembles around the virus genome.

The genome is “fed” into preformed capsids

Question 7

Enveloped viruses acquire the envelope from a variety of cellular membranes by

Answer 7

budding

Question 8

• cellular proteins that catalyze or assist the folding of individual protein molecules

Answer 8

Viral Assembly

Question 9

Viruses that bud into the plasma membrane are released into the extracellular environment ______

Answer 9

directly

Question 10

Viruses that bud into the membranes of the Golgi apparatus or endoplasmic reticulum are secreted from the _____.

Answer 10

infected cell

Question 11

• cell transport systems move viral proteins and nucleic acids to sites of assembly

Answer 11

Viral Assembly

Question 12

Viruses are obligate intracellular parasites, therefore we generally cannot see virus infection & replication, and instead we see the effects of viral infection & replication on_______

Answer 12

infected cells and tissues.

Question 13

The ______specific virus and the specific cell or target tissue.

Answer 13

result of viral infection of a cell depends on the

Question 14

• Membrane proteins enter the secretory pathway

Answer 14

Viral Assembly

Question 15

Viruses are _______, therefore a delicate balance with host is necessary for survival

Answer 15

obligate intracellular parasites

Question 16

______ or primary defenses are immediate and non- specific.

Answer 16

Innate

Question 17

• Nuclear proteins use nuclear import machinery

Answer 17

Viral Assembly

Question 18

Indirect cell damage from a virus can result from

Answer 18

• integration of the viral genome
• induction of mutations in the host genome
• inflammation
• host immune response

Question 19

________ result in the destruction of the host cell

Answer 19

Lytic infections

Question 20

Enveloped viruses acquire the _____ from a variety of cellular membranes by budding

Answer 20

envelope

Question 21

• Subunits move on the cytoskeleton using cellular motors

Answer 21

Viral Assembly

Question 22

Viruses are _______, therefore we generally cannot see virus infection & replication, and instead we see the effects of viral infection & replication on infected cells and tissues.

Answer 22

obligate intracellular parasites

Question 23

Innate or primary defenses are immediate and non- specific.

Adaptive immunity is acquired during infection and results in immunologic memory, that is a quantitatively and qualitatively _______ upon second exposure.

Answer 23

enhanced response

Question 24

__________ include enveloped viruses that are released by budding (without lysis of the cell) and may occur over relatively long periods of time

Answer 24

Persistent infections

Question 25

________show a delay between the infection and appearance of symptoms.

Answer 25

Latent infections

Question 26

_________ can be caused by some viruses, conferring cell growth without restraint. These are called oncogenic viruses.

Answer 26

Transformation

Question 27

Innate defenses include:

Answer 27

natural barriers, cells, soluble factors

Question 28

Type I IFNs (include IFNa and IFNb)

Answer 28

• antiviral cytokines transiently produced and secreted by most infected cells within hours of infection.

Question 29

Type II IFN (IFNg) is produced:

Answer 29

mainly by T cells and NK cells, more restricted than Type I IFN production.

Question 30

Cells respond to _____ through receptor activation of Jak/Stat signaling

Answer 30

IFN

Question 31

________ and the inflammatory response are critical precursors to the adaptive immune response to viruses.

Answer 31

Innate immunity

Question 32

IFN alters transcription of more than ______ cellular genes

Answer 32

100