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virology > RETRO > Flashcards

RETRO Flashcards

1
Q

What enzyme does this virus family use to produce DNA intermediates from their RNA genome?

A

Reverse Transcriptase

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2
Q

An RNA-dependant DNA polymerase that is present within the virions of all members of the family.

A

Reverse Transcriptase

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3
Q

True or False

Retro viruses infect a wide variety of animals and humans , can produce latent infections, and are associated with certain types of cancers.

A

TRUE

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4
Q

Retro

ENVELOPED or NOT?

A

ENVELOPED

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5
Q

Name the 3 genes that all non defective retroviruses have.

A

GAG- encodes virion core proteins

POL- encodes reverse transcriptase and integrase

ENV- encodes the envelope proteins

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6
Q
A
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7
Q

How does the virus penetrate the cell membrane?

A

Membrane Fusion

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8
Q

Can the virus use endocytosis or exocytosis to gain entry inside the cell?

A

Endocytosis

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9
Q

Unlike HIV, Retros do not need a co factor.

True or False

A

False

Retro viruses may require a co receptor like HIV

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10
Q

What enzyme is used to intergrate the viral DNA into the host cellular chromosomal DNA ?

A

Integrase enzyme

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11
Q

Maturation of virions occurs by _________ through the host cell plasma membrane.

A

BUDDING

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12
Q

Assembly and packaging of viral protein, encapsidation or viral RNA occurs in the ___________.

A

Cytoplasm

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13
Q

_____________ is replicated with host genome and can be passed to daughter cells resulting in transmission from one generation to the next.

A

PROVIRUS

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14
Q

The replication of retros is accompanied by high mutation frequency that is due to the lack of _________________ by reverse transcriptase.

A

3’ to 5’ exonuclease proofreading mechanism

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15
Q

What are non pathogenic DNA stretches found widely in genome of most vertebraes that closely resemble retros?

A

Endogenous retroviruses

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16
Q

All RNA tumor viruses belong to the family Retroviridae.

TRUE or FALSE

A

TRUE TRUE TRUE

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17
Q

What gene does the acute transforming retroviruses carry that makes them directly oncogenic by having the power of unregulated expression and are under the control of viral LTRs?

A

v-onc

Remember: c onc/proto oncogenes are host genes that encode important cell signaling porducts that regulate normal cell proliferation

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18
Q

What gene does the virus loose during recombination and what gene does the virus aquire?

A

Looses its own ENV gene

Gains the host PROTO-ONCOGENE

Note: This makes v-onc containing viruses unable to synthesize a complete envelope, are replication defective and must associate with non defective viruses to replicate

**EXCEPTION: Rous sarcoma virus **

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19
Q

A type of Retrovirus that does not contain the v-onc gene.

A

Slow/Chronic Transforming Retrovirus

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20
Q

Etiology

Bovine Leukemia

(Enzootic Bovine Leukosis)

A

Deltaretrovirus

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21
Q

What is the unique sequence in Bovine Leukemia Virus that is not of host cell origin between ENV and 3’LTR?

A

pX

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22
Q

What is the regulatory protein that is encoded in the pX region, activates the replication of BLV and contributes to the induction of lymphoma(oncogenesis)?

A

Tax protein

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23
Q

In what cells is the Bovine Leukemia virus mostly present?

A

B lymphocytes

Therefore can be found in blood, milk and tumor masses.

24
Q

Name the 6 modes of transmission for the Bovine Leukemia Virus

*Remember virus is in B lymphocytes, so how can B lymphocytes be transmitted*

A
  1. Blood Transfusion
  2. Iatrogenic
  3. Rectal Palpation
  4. Mechanically by blood sucking insects
  5. Vertical(in utero)
  6. Colostrum or milk
25
Q

What cells and what immunoglobulin are the primary target of Bovine Leukemia Virus?

A

B Lympohocytes that express IgM

26
Q

What 2 ways does Bovine Leukemia virus escape immune elimination?

A
  1. By controlling viral gene expression in vivo
  2. Promoting cells survival by inhibiting apoptosis
27
Q

Cattle with BoLA-Aw7 alleles are:

resistant or susceptible

to Bovine Leukemia Virus?

A

BoLA-Aw7

RESISTANT TO THAT SHIT!

7 is God’s favorite number = good= resistant

28
Q

Cattle with BoLA-Aw12 alleles are:

**resistant or susceptible **

to Bovine Leukemia Virus?

A

BoLA-Aw12 allele

SUSCEPTIBLE :(

Poor Cow

29
Q

Primary infection of Bovine Leukemia virus gives of what kind of clinical signs?

A

Asymptomatic or flu like

30
Q

When can you detect the levels of antibodies after infection of Bovine Leukemia Virus?

A

4 to 12 weeks after exposure

31
Q

In what phase of pathogenesis of BLV lasts for several months/years, the animal shows no signs, and they become latent carriers of the infection?

Primary Phase

Persistant Infection

Persistant Lymphocytosis

Tumor Phase

A

PERSISTANT INFECTION

Lucky cows to be persistantly infected but show no signs.

32
Q

Persistant lymphocytosis and benign proliferation of B lymphocytes are characteristcs of what pahse of Bovine Leukemia Virus?

A

Persistant Lymphocytosis

Morbidity, weakness and opportunistic infections

33
Q

In what phase of pathogenesis does the animal infected with Bovine Leukemia begin to develop lymphosarcomas?

A

TUMOR PHASE

Animal undergoes sudden death because of hemorrhage of the spleen.

34
Q

True or False:

Seropositive(persistantly infected) animals with or without persistant lymphocytosis may develop lymphosarcoma.

A

TRUE TRUE TRUE

35
Q

What is the age range of cattle where the tumor phase of Bovine Leukemia usually observed?

A

4-8 years of age = Tumor Phase

36
Q

Bovine Leukemia can cause lesions in which of the following areas in cattle:

*More than one option*

Vagina

Digestive Tract

Eye

Lymph nodes

Liver & Kidney

Lungs & Heart

A

Digestive Tract

Lymph Nodes

Liver & Kidney

Lungs & Heart

*That includes the ABOMASUM*

38
Q

An increase in the absolute number of peripheral blood circulating B-lymphocytes(above 10,000/mm).

A

Persistant Lymphocytosis

39
Q

What 2 viral proteins will the cattle continously have antibodies against and can be detected in their serum when doing AGID test?

A

Major Internal(p24) and Envelope(gp51)

40
Q

Identification of cattle infected with Bovine Leukemia virus can be done by using what serological test?

41
Q

Once you identify the seropositive animals for Bovine Leukemia, what should you do IMMEDIATELY?

A

KILL THEM ALL

Poor cows :(

42
Q

After you have killed all the cattle infected with Bovine Leukemia virus, when should you retest the herd Dr. Lemoine?

A

30-60 days later

43
Q

When there is low prevalence of Bovine Leukemia in your herd, what test should you use on the calves and doubtful cases?

44
Q

“If I test the cows in your herd today and they are negative for Bovine Leukemia farmer Pete, then I will come back to your farm every ______ months for 2 years and declare your herd free of the virus “

A

6 months

MAKE SURE YOU HAVE STRICT FARM BIOSECURITY!!!

45
Q

What are the three forms of Sporadic Bovine Leukosis?

A

Juvenile, Thymic, and Cutaneous

46
Q

Which form of Sporadic Bovine Leukosis shows enlargement of all lymph nodes and bone marrow necrosis?

47
Q

The form of Sporadic Bovine Necrosis that shows brisket edema and jugluar vein engorgement and massive thymic enlargement is ____________.

A

Thymic form

48
Q

This form of Sporadic Bovine Leukosis affects cattle 1-3 years old and shows cutaneous plaques and nodules on the neck, back, croup, and thighs.

49
Q

Etiology

Feline Leukemia VIrus

(FeLV)

A

Gammaretrovirus

50
Q

What protein involved in FeLV ,is encoded by the gag gene and is the major FeLV group specific antigen?

A

p27 protein

51
Q

___________forms the primary structural proteins of the core of the virus.

A

Capsid Protein

52
Q

Most serological assays for FeLV are designed to detect what protein?

A

p27 protein

53
Q

p27 protein is found in the _________ of the infected cells and in the ________ form in blood, tears and saliva.

A

cytoplasm; free

54
Q

What protein associated with FeLV is encoded by env gene, is a transmembrane protein, plays a role in immunosuppression and facilitates virus persistance?

A

p15E protein

55
Q

p15E protein plays a role in immunosuppression by _____________ lymphocyte blastogenesis, ___________the response of T cells to IL1 & IL2 and by _________the response to FOMCA.

A

suppressing; blocks; supressing

56
Q

What protein involved in FeLV is also encoded by the env gene but is responsible for the attachment of the virus to the host cell?

A

gp70 protein

“Yo G come over here and attach to me before I turn 70”

virology (8 decks)

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