DD- HOST RESPONSE Flashcards Preview

BL/DD USMLE and Basics > DD- HOST RESPONSE > Flashcards

Flashcards in DD- HOST RESPONSE Deck (32):
1

Virus Structure/Function

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

2

All RNA viruses encode an:

RNA-dependent RNA polymerase RdRp

3

Seven Classes of Viral Genomes and Replication schemes

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

4

Production of virus particles depends on host cell machinery:
Assembly

- 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

5

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

coated with nucleocapsid protein

6

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

The capsid assembles around the virus genome.

The genome is “fed” into preformed capsids

7

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

budding

8

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

Viral Assembly

9

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

directly

10

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

infected cell

11

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

Viral Assembly

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_______

infected cells and tissues.

13

The ______specific virus and the specific cell or target tissue. 

result of viral infection of a cell depends on the

14

- Membrane proteins enter the secretory pathway

Viral Assembly

15

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

obligate intracellular parasites

16

______ or primary defenses are immediate and non- specific.  

Innate

17

- Nuclear proteins use nuclear import machinery

Viral Assembly

18

Indirect cell damage from a virus can result from

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

19

________ result in the destruction of the host cell

Lytic infections

20

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

envelope

21


- Subunits move on the cytoskeleton using cellular motors

Viral Assembly

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.

obligate intracellular parasites

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.

enhanced response

24

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

Persistent infections

25

________show a delay between the infection and appearance of symptoms.

Latent infections

26

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

Transformation

27

Innate defenses include:

natural barriers, cells, soluble factors

28

Type I IFNs (include IFNa and IFNb)

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

29

Type II IFN (IFNg) is produced:

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

30

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

IFN

31

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

Innate immunity

32

IFN alters transcription of more than ______ cellular genes

100