Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Immunology > Lecture 19 - Viruses And Immune Evasion > Flashcards

Lecture 19 - Viruses And Immune Evasion Flashcards

1
Q

What is a virus?

A

A package of genetic information protected by a protein shell for delivery into a hostel cell to be expressed and replicated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

How old is Virology?

A

Approx 100 years old

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

I’m Ancient Greece, what does ios mean?

A

A poisonous substance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

In Latin, what is Virus?

A

A poisonous malodorous substance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What dates before 1,000 B.C.E?

A

Mesopotamian laws concerning rabid dogs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Where was Small pox endemic in?

A

Ganges river basin by the 5th century B.C.E

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Who was the first to attempt to rationalise plagues?

A

Hippocrates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What did Hippocrates conclude about plagues?

A

caused by small animals in the air too small for human vision

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the order of Viral Replication?

A
  1. Virus Entry
  2. Uncoating
  3. Genome replication
  4. Protein synthesis
  5. Virus-assembly and maturation
  6. Virus release
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is Primary Replication ?

A

The place of primary replication is where the virus replicates after gaining initial entry into the host
This determines whether the infection will be localised at site of entry or spread to become a systematic infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is systemic spread?

A

Apart from direct cell-to-cell contact, the virus may spread via blood stream and the the CNS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Where does secondary reviews location take place?

A

Susceptible organs/tissues following systemic spread

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is disease mechanisms for Rabies virus?

A

Transmitted by saliva
Bite of rabid animal
Aerosois in caves populated by infected bats

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Where does Rabies Virus replicate?

A

Muscle at bite site

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How long is the incubation period and what does it depend on (Rabies Virus)?

A

Weeks to months

Depend on: inoculum and distance of bite from CNS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What does Rabies Virus infect?

A

Peripheral nerves and travels to brain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

(Rabies Varies) what does Replication in Brain cause?

A 
Hydrophobia 
seizures 
Hallucinations
Paralysis 
Coma 
Death
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Where does Rabies Virus spread to?

A

Salivary gland from where it is transmitted

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What can prevent disease due to long incubation period (Rabies Virus)?

A

Post exposure immunisation

20
Q

Rabies Virus

A

Virus Inoculated
Viral replication in muscle
Virion enters peripheral nervous system
Replication in dorsal ganglion
Rapid ascent in spinal cord
Infection of spinal cord, brain stem, cerebellum and other brain structures
Descending infection via nervous system to eyes, salivary gland, skin, and other organs

21
Q

What is co-evolution with Host?

A

Host and parasite exert reciprocal selective pressure on each other
Rapid reciprocal adaptation

22
Q

What is advantage of co-evolution with Host?

A

Prosperous host = prosperous Virus

23
Q

What is disadvantage of co-evolution?

A

Virus shares same fate as host
Genetic bottleneck events can be fatal
Typically used by DNA viruses

24
Q

What is adavantage of multiple host species?

A

If one host species is compromised, Virus can replicate in another

25
Q

What is disadvantage in infection of multiple host species?

A

Cannot optimise for any one situation

26
Q

What uses infection of multiple host species?

A

RNA viruses

27
Q

Define viral evolution

A

The constant change of viral population In the face of selection pressures

28
Q

What happens if population can’t change or adapt?

A

It disappears

29
Q

What does viral population display?

A

Spectacular diversity

30
Q

What are sources of diversity?

A

Mutation

Recombination

31
Q

What are mechanisms of viral evolution?

A

Mutation (adaptation)
Recombination
Ressortment
Selection

32
Q

What does mechanisms of viral evolution depend on?

A

Large population size

Progeny

33
Q

What are the features of DNA viruses?

A 
Narrow host range 
Persistent infection common 
Not as much Replication 
Genome replication not as error prone 
Proof reading 
Generate less diversity 
Evolve slower
34
Q

Features of RNA viruses

A

Masters of error prone replication

RNA polymerase cannot correct errors

35
Q

What is the average error frequency of RNA viruses ?

A

1 in 10^4 or 10^5 nucleotides polymerised

36
Q

In 10kb RNA Virus genome, what is mutation frequency of RNA virus?

A

1 in 10^4

37
Q

What is quasispecies?

A

Virus population exist as dynamic distribution of non-identical but related replicons

38
Q

What is an example of small RNA virus?

A

Human influenza virus

39
Q

What are features of small RNA virus ?

A

Interference with innate immunity (type I interferon)
Blockade of host gene transcription
Antigenic hypervariability

40
Q

What is small RNA virus also known as?

A

Hit and run

41
Q

What does small RNA virus cause?

A

Elimination of virus

42
Q

What is an example of large DNA virus?

A

CMV

43
Q

What are features of large DNA virus ?

A

Interference with adaptive immunity
Replication at immunoprivileged sites
Molecular latency

44
Q

What can large DNA virus cause ?

A

Persistent infection

45
Q

What is large DNA virus also known as?

A

hit and hide

46
Q

What are the viral immune evasion strategies?

A

Viral evasion of MHC class-I mediated Antigen presentation
Viral evasion of MHC class-II mediated Antigen presentation
Viral evasion of natural killer cell activation
Viral evasion of antibody responses and complement attack

Immunology (20 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions