Retroviridae

Question 1

why retro?

Answer 1

retro - reverse transcription

Question 2

Subfamilies

Answer 2

• Orthoretrovirinae

- Spimaretrovirinae

Question 3

Ortoretrovirinae genera

Answer 3

Alpha-, Beta-, Gamma-, Delta-, Epsilonretrovirus and Lentivirus genus

Question 4

Spumaretrovirinae genera

Answer 4

Bovi-, Equi-, Felispurmavirus genus

Question 5

Morphology

Answer 5

diploid (only diploid virus), +ssRNA genome, helical + icosahedral capsid, enveloped, big

Question 6

Resistance

Answer 6

very sensitive viruses (one of the most sensitive viruses)

Question 7

Replication

Answer 7

Baltimore VI - viral reverse transcriptase -> integration, provirus

Question 8

Type of infection

Answer 8

Cell-associated infection, because the cells protect the viruses from the environment

Question 9

Genetic structure

Answer 9

characteristic, SHORT
5’-LTR-gag-pro-env-pol-LTR-3’
+/- onc, substitution mutant -> transforming, defective virus

Question 10

what does onc gene sequence cause?

Answer 10

tumors

Question 11

what sequence does “onc” usually replace?

Answer 11

env - the sequence for envelope

Question 12

Oncogenic = ?

Answer 12

transforming viruses, need helpers for multiplication

Question 13

multiplication competent viruses

Answer 13

Strong CPE, oncogenic as well

Question 14

Transmission

Answer 14

transplacental (tolerance!), cell associated (germ cells, colostrum, epithel), arbo

Question 15

Antigenic properties

Answer 15

• good antigens
• hypervariable surface antigens, Ig-s are not effectige against integrated viruses (->life long infection), destruction of the immune-system (destrow WBC - attack lymphatic tissue)

Question 16

Cross-reactions?

Answer 16

yes, specificity of antigens (core

Question 17

Clinical signs

Answer 17

tumor formation &/or immunosupression

Question 18

Diagnosis

• direct
• indirect

Answer 18

• Direct: ELISA, IF, PCR, NA hybridization

- Indirect: ELISA (produce many false positive), AGID (Coggins-test - EIA)

Question 19

Orthoretrovirinae - Alpharetrovirus genus

-Avian sarcoma, Av. myeloblastosis, Av. carcinoma virus

Answer 19

• carry onc gene
• defective virus - helper: leucosis virus
• chicken: quick developing mesenchymal tumors

Question 20

Orthoretrovirinae - Alpharetrovirus genus

Rous sarcoma virus

Answer 20

• only virus which is both enveloped and have the onc gene!
• multiplication competent and viral onc gene
• chicken: mesenchymal sarcomas

Question 21

Orthoretrovirinae - Betaretrovirus genus

Bovine pulmonary adenocarcinoma virus

Answer 21

sheep: lung cancer (“Jaagsiekte) -> unable to breathe

Question 22

Other Betaretroviruses

Answer 22

-Mouse mammary tumor virus
-Monkey retrovirus
both lead to tumors

Question 23

Orthoretrovirinae - Gammaretrovirus genus

Answer 23

replicate competent or defective viruses

Question 24

Orthoretrovirinae - Gammaretrovirus genus

Mammalian group

Answer 24

• Feline leukemia/sarcoma virus

- Murine leukemia/sarcoma virus

Question 25

Orthoretrovirinae - Gammaretrovirus genus | Reptilian group

Answer 25

Viper retrovirus -> health problems (ex. fever) in snakes

Question 26

Orthoretrovirinae - Gammaretrovirus genus | Avian (reticuloendotheliosis) group

Answer 26

- Reticuloendotheliosus virus: chicken -> immunosupression, tumors - Chicken syncytial virus, Duck spleen necrosis virus

Question 27

Orthoretrovirinae - Deltaretrovirus genus | Bovine leukemia virus (NF!)

Answer 27

BLV = bovine leukemia virus -Cattle: leucosis, slow-developing lymphatic tumours (check for infection once a year)

Question 28

Orthoretrovirinae - Deltaretrovirus genus | Human T-lymphotropic virus 1-2 (HTLV)

Answer 28

human T-cell leukemia = transformation of leukocutes -> immunosupression and tumors

Question 29

Orthoretrovirinae - Epsilonretrovirus genus (fish) - Walleye dermal sarcoma virus - Walleye epidermal hypoplasia virus

Answer 29

Both lead to skin changes and eventually death

Question 30

Orthoretrovirinae - Lentivirus genus | lenti meaning

Answer 30

lentus = slow

Question 31

Orthoretrovirinae - Lentivirus genus | Equine infectious anaemia virus (NF!)

Answer 31

EIA = equine infectious anaemia horse: anemia (due to Ø prod. of RBC), wasting - leathal (checked every year: + isolated from the herd)

Question 32

Orthoretrovirinae - Lentivirus genus | Maedi-Visna virus (NF!)

Answer 32

sheep -Maedi = interstitial pneumonia -Visna = encephalitis +tumor

Question 33

clinical sign of Maedi-Visna virus

Answer 33

labored breathing, usually in older animals

Question 34

Orthoretrovirinae - Lentivirus genus | Caprine arthritis-encephalitis virus (CAE)

Answer 34

goat: arthritis, lameness, encephalitis, paralysis

Question 35

Orthoretrovirinae - Lentivirus genus | Human immunodeficiency virus 1, 2 (HIV 1-2)

Answer 35

T-helper cell destruction - immunosupression -> acquired immunodeficiency syndrome (AIDS), ARC

Question 36

Orthoretrovirinae - Lentivirus genus | other immunodeficiency viruses

Answer 36

- FIV = felina immunodeficiency virus - BIV = bovine deficiency virus - SIV = simian immonudeficiency virus

Question 37

Spumaretrovirinae | meaning of spuma

Answer 37

spuma = foamy

Question 38

Spumaretrovirinae genera

Answer 38

Bovi-, Equi-, Felispumavirus genus