L33_RNA Viruses 2

Question 1

What type of virus is rotavirus, what type of genome, is it segmented, is it enveloped, what shape capsid?

Answer 1

Reovirus, dsRNA, segmented, naked, icosehedron

Question 2

What type of virus is the influenza virus, what type of genome, is it segmented, is it enveloped, what shape capsid?

Answer 2

Orthomyxovirus, - ssRNA, segmented, enveloped

Question 3

What type of virus is HIV, what type of genome, is it segmented, is it enveloped, what shape capsid?

Answer 3

Retrovirus, + ssRNA (2copies), enveloped

Question 4

What does rotavirus cause, and what are the main symptoms?

Answer 4

Causes severe gastroenteritis, profuse watery diarrhea, dehydration, maladsoption

Question 5

What demographic does rotavirus generally infect and what is the peak season?

Answer 5

Affects infants and children, peak incidence during the winter.

Question 6

What is unique about rotavirus uncoating?

Answer 6

It never fully uncoats, it just loosens and allows necessary particles to enter and leave, so it protects it mRNA

Question 7

How does rotavirus egress?

Answer 7

Either through cell lysis, or it buds into the RER and uses the secretory pathway (when doing this it acquires a temporary lipid envelope)

Question 8

When does a rotavirus virion become infectious?

Answer 8

After processing in the gut lumen

Question 9

What prevention and treatment methods are used for rotavirus?

Answer 9

Prevention: Two live attenuated vaccines
Treatment: Oral rehydration

Question 10

What are the common symptoms of the flu?

Answer 10

Headache, Fever, Muscle weakness, joint aches, limited runny or stuffed nose, sore throat, coughing, nausea and vomiting

Question 11

How many segments are in an influenza genome?

Answer 11

8

Question 12

Where does flu virus transcription and replication take place?

Answer 12

In the nucleus, each segment of DNA has a nuclear localization signal. Each segment has RDRP on its end.

Question 13

How do new flu virions assemble and egress?

Answer 13

They assemble at the plasma membrane and bud outwards.

Question 14

What is the last step required to release a new flu virion?

Answer 14

The haemaglutinin is stuck to all sialic acid on surface of cell, so you need Neuraminidase to cleave these bonds and release the new virion into the extracellular space.

Question 15

How is the flu virus transmitted from person to person?

Answer 15

respiratory droplets

Question 16

What is a major target of flu drugs?

Answer 16

Inhibiting neuraminidases from cleaving hemaglutinin-sialic acid link

Question 17

What type of treatments are available for people with the flu?

Answer 17

Antiviral drugs

Question 18

Is the flu shot a live vaccine?

Answer 18

No it is inactivated

Question 19

Is the flu mist a live vaccine?

Answer 19

Yes but it is attenuated given that it can only replicate in the cool parts of your respiratory tract.

Question 20

How many strains are covered by a typical flu vaccination?

Answer 20

3 different strains, that change depending on the predicted circulation for that season.

Question 21

What is the difference between Antigenic shift and drift?

Answer 21

Shift= genetic shuffling
Drift= random mutation

Question 22

how often do flu pandemics happen?

Answer 22

every 10-12 years

Question 23

List some symptoms of acute HIV infection

Answer 23

Fever, weight loss, mouth sores and thrush, myalgias, liver and spleen enlargement, systemic lymphadenopathy, nausea and vomiting, headache, possible rash

Question 24

What does the HIV virus bid to?

Answer 24

CD4 and chemokine receptors on T cells and macrophages

Question 25

Have antibodies shown any effectiveness agains AIDS?

Answer 25

No

Question 26

How does an HIV virus enter a cell?

Answer 26

It binds to CD4 and co-receptor and fuses with the cell

Question 27

Describe the un-coating of HIV virus

Answer 27

similar to rotavirus, HIV does not completely un-coat

Question 28

Describe the life cycle of HIV once in the cell

Answer 28

Reverse transcriptase produces a compliment strand to the two copies of the + ssRNA genome. These copies migrate into the nucleus and are inserted into the host genome. The host RNA poly 2 transcribes the viral genome, this transcript can be used for protein synthesis or as a genome of a new virion.

Question 29

describe the translation and modification to produce final HIV proteins.

Answer 29

The initial translation creates a poly protein which then needs to be cleaved by a protease into individual protein. Protease inhibitors are a major drug target.

Question 30

Describe the maturation and egression of the HIV virus.

Answer 30

2 copies of the ssRNA genome and viral proteins egress from the cell by budding. Final maturation happens outside of the cell where proteases help rearrange capsid proteins into the final trapezoidal shape. This final maturation process is another target for HIV drugs

Question 31

What metrics are used to diagnose HIV?

Answer 31

Serological assay for antibodies (GP120)
Nucleic Acid assays for viral load
CD4 T cell count

Question 32

What are some prevention measures used for HIV?

Answer 32

Risk avoidance, community awareness, Public health measures, Antiviral Drugs (Chemoprophylaxis)

Question 33

How many different Antiretroviral Therapies are used on a person to treat AIDS

Answer 33

Multiple to avoid resistance.

Question 34

What are some of the types of HIV drugs?

Answer 34

Nucleoside inhibitors, non-nucleoside inhibitors, protease inhibitors, integrase strand trasnfer inhibitors, CCR5 antagonists

Question 35

What do the H and N stand for in typing a flu?

Answer 35

Hemagluttinin and Neuraminidase

Question 36

What two RNA virus virions undergo final maturation outside of the cell?

Answer 36

HIV and Rotavirus.

Question 37

Name a few differences between the flu and primary HIV infection symptoms

Answer 37

In primary HIV you dont have the cough and nasopharynx symptoms. you also see mouth sores and hepto and splenomegaly, systemic lymphadenopathy