Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

RUSVM Virology Spring17 > Retroviridae > Flashcards

Retroviridae Flashcards

(68 cards)

Start Studying
1
Q

What do retroviruses cause?

A

immunosuppression, immune deficiency, cancer

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

What do all retroviruses need to replicate?

A

Reverse transcriptase

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

What three scientist discovered the importance of reverse transcriptase in retroviruses?

A

Baltimore, Dubelco, Temin

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

Reverse transcriptase is a

A

RNA dependent DNA polymerase (found in the virion of all retroviruses)

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

T/F: Retroviruses are enveloped

A

TRUE

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

T/F: Retroviruses have a triploid genome

A

FALSE.

Retroviruses have a DIPLOID genome: two single stranded copies of positive sense RNA

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

T/F: Since retroviruses have positive sense RNA, they directly synthesize proteins

A

FALSE.

Positive sense RNA is used as a template for DNA –> then makes RNA –> protein synthesis

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

What enzyme allows retroviruses integrate into the host cell genome?

A

INTEGRASE

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

What shape are retroviruses?

A

Spherical

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

T/F: Retroviruses are NOT easily inactivated by lipid solvents or heating.

A

FALSE

Easily inactivated by these due to envelope

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

T/F: Retroviruses are resistant to UV and X-rays

A

TRUE

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

What are the 4 most important genes retroviruses have, and what do they encode for?

A

gag - encodes for core proteins: capsid, nucleocapsid, matrix
pol - encodes for reverse transcriptase & integrase
env - encodes for surface and transmembrane proteins
pro - encodes for protease

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

What are the two subfamilies of retroviridae?

A

Supumaretrovirinae

Orthoretrovirinae

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

What are the genera of the subfamily Orthoretrovirinae?

A 
alpharetrovirus
betaretrovirus
gammaretrovirus
deltaretrovirus
epsilonretrovirus
lentiretrovirus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Which genera of the Orthoretrovirinae subfamily are simple retroviruses?
What is a simple retrovirus?

A

Alpha, beta, gamma
Simple retroviruses have only the core retrovirus genes: gag, pol, pro, env
They are BOTH Endogenous and Exogenous

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

To which genus does Mouse Mammary Tumor Virus (MMTV) belong?
What is the unique gene it encodes for?
What is the significance of this virus?

A

MMTV is a betaretrovirus. It is often and most commonly used as an experimental virus model. It encodes for the sag gene - super antigen.
Important for research

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

What does it mean if a virus is Exogenous?

A

It can be transmitted HORIZONTALLY.

rarely in-utero or germline

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What does it mean if a virus is Endogenous?

A

The virus is included within the host genome.

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

What are some alpharetroviruses?

A

Avian leucosis virus
Avian Sarcoma virus
Avian myeloblastosis virus
Rous sarcoma virus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are some gammaretroviruses?

A

Feline Leukemia virus
Feline sarcoma virus
Avian reticuloendotheliosis virus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Examples of deltaretroviruses?

A

Human T-lymphotropic virus (HTLV)

Bovine leukemia virus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What genus does Walleye dermal sarcoma virus belong to? Who does it infect?

A

Epsilonretrovirus

Fish

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

HIV is what kind of virus?

A

Lentivirus

Other viruses in the genus: Caprine arthritis-encephalitis virus and Meadi-visna virus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

T/F: Epsilonretroviruses are endogenous only

A

TRUE

In fish and reptiles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
T/F: Deltaretroviruses are endogenous only
FALSE: | Exogenous only
26
Are lentiretroviruses exogenous, endogenous, or both?
Exogenous
27
What is required for a retrovirus to enter a host cell?
Cell surface molecule receptor + envelope proteins on the virion surface (Retrovirus cell receptors) Each genus has a specific receptor(s)
28
When a retrovirus is actively lysing host cells, what stage of disease is present?
Acute disease
29
Insertion and or mutation through virus integration is describing what stage of disease?
Chronic
30
The process by which a retrovirus acquires a cellular oncogene and modifies it into a viral oncogene is what?
ONCOGENESIS
31
What two specific proteins does of FeLV env gene encode for?
gp70 - surface protein | p15E - transmembrane protein **BLOCKS T CELL reactivity
32
What specific protein does the FeLV gag gene encode for? | What is its importance?
p27 - Many diagnostic tests are based on this protein, including ELISA
33
T/F: FeLV survives well in the environment
FALSE | Does not survive well outside of the host. It is easily killed by disinfectants, soap, heating, and drying
34
What is the % prevalence of FeLV in a single cat house hold? Multi-cat house hold?
Single cat home - 1% | Multi-cat home - 20%
35
What cats spread FeLV and how?
Cats with viremia are the source of infection via: saliva, nasal secretions, feces, and milk **Mutual grooming** and cat bites are most common modes of transmission
36
What factors will increase a cats potential of FeLV infection?
young age high population density poor hygiene
37
What are the two versions of the feline leukemia virus?
``` Endogenous FeLV (enFeLV) RD114 virus ```
38
What are the different Subtypes of FeLV
Subtype A, B, C, T
39
What occurs when a pregnant cat is FeLV positive?
Abortion still birth or viremic kittens are born (carriers)
40
What is the progression of FeLV? (Where does infection begin and spread)
Infection typically begins in the oral or pharyngeal tissue then progresses to the lymphoid tissue. The virus will spread to peripheral tissue via Monocytes and lymphocytes Viremia occurs within a few weeks - months
41
Where does the FeLV virus have a tropism for?
T-lymphocytes and lymphoid tissue
42
What receptors does the FeLV virus use to attack T-lymphocytes?
Pit1 (phosphorus transportation protein 1) | FeLIX (FeLV infectivity X-essory protein)
43
What is the cellular consequence of FeLV?
Decrease in CD4+Tcells = immunosuppression = highly susceptible to secondary infections Wasting syndrome and atrophy of the thymus due to recurrent infections
44
T/F: When a patient has FeLV, they can fight off other infections with their cellular immunity
FALSE | FeLV ruins the cellular immune response
45
What is the GOLD STANDARD Dx test for FeLV?
Isolation of virus from cell culture is the BEST diagnostic (but it can be $$$$$ and not all labs perform this test) ELISA and IFA are good dx Real time PCR and Reverse transcriptase PCR (DNA confirms virus, RNA confirms live/active infection)
46
Is the FeLV vaccine 100% effective?
NO
47
T/F: You should recommend euthanasia if a cat tests positive for FeLV
FALSE These cats can live a long life. They should be kept INDOOR ONLY to prevent further spread of the virus and secondary infections. These cats should be in a single cat home.
48
What is the most common mode of FIV transmission?
DEEP BITE WOUNDS
49
What age group is most susceptible to FIV infections?
ALL AGES Outdoor cats and Feral cats are the most susceptible
50
What doctors discovered the FIV infection at UC Davis in 1986?
Yamato and Pederson
51
What percentage of cats are FIV positive in the United States?
25%
52
What genus is FIV in?
Lentivirus
53
What is the best dx test for FIV?
ELISA
54
What clinical signs may you seen in a cat with FIV?
``` Persistent fever and DHR Decreased appetite weight loss gingivitis and stomatitis recurrent skin infections, UTI, URIs ``` Sometimes cancer and blood dz CNS signs = terminal phase
55
T/F: there is treatment to eliminate FIV
``` FALSE There is no tx to eliminate FIV - can only tx symptomatically AB for secondary infections Appetite stimulants Corticosteroids Immune modulators etc ```
56
T/F: A cat that is vaccinated for FIV, will always test positive in the future
TRUE | They will always be FIV antibody positive
57
What are the two types exogenous avian retroviruses?
Replication Competent: usually non pathogenic in most chickens Replication Defective: virus goes immediately into DNA, acquires viral oncogene(s) and causes malignant tumors
58
What differs in the pathogenicity in chickens who get an avian retrovirus that is replication defective via horizontal transmission or via vertical transmission?
Horizontal: chickens are usually infected @ 5 days old, will have transient viremia and are unlikely to develop leukemia Vertical: congenital or genetic infections - persistent viremia, tends to progress to leukemia
59
T/F: Chickens with lymphoid leukosis will produce large amounts of IgM
TRUE
60
T/F: Lymphoid leukosis is the most common form found in chickens 4-30wks of age
TRUE
61
If you run a Coggins test, what are you trying to diagnose and who is your patient?
Equine Infectious Anemia - Horse of course ;)
62
Where does equine infectious anemia replicate?
Infects monocytes - then replicates in macrophages
63
What kind of hypersensitivity is associated with equine infectious anemia?
Type II hypersensitivity | think blood!
64
What are some clinical signs of equine infectious anemia?
Anemia and Thrombopenia = petechial, edema, lethargy, fever, weight loss, splenomegaly, depression
65
T/F: Flies can transmit equine infections anemia
TRUE When a fly is interrupted in feeding - it is more likely to bite again right away. This is when virus transmission is most likely
66
T/F: A horse with EIA will always be symptomatic
FALSE | there are asymptomatic carriers
67
T/F: Horses can pass EIA to their foals via milk and colostrum
TRUE MOT: blood - via insects or instruments Venereal, milk, colostrum
68
What avian diseases are caused by retroviruses?
lymphoid leukosis osteoporosis "Thick leg syndrome" Eythroblastosis

RUSVM Virology Spring17 (23 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions