LEC 16 - Retrovirals II Flashcards
ALV - Envelope proteins
gp 85+ 37
ALV - Capsid proteins
p27
ALV - Enzymes
RT
Integrase
Protease
ALV subgroups that infect chickens?
A to E + J
What does ALV cause in chickens?
Leukosis
What types of leukosis are seen with an ALV infection?
Lymphoid (most common)
Erythroud
Myeloid
What are the three common tumor types that are seen with ALV infections?
Fibrosarcomas
Hemangiosarcomas
Nephroblastomas
What methods is ALV transmitted?
Horizontally
Vertically
How is ALV transmitted vertically?
Hen shed virus to albumen + yolk
What happens to chickens that are infected in the egg?
Do not produce neutralizing antibodies
Remain viremic for life
Increased risk of neoplasms
How is ALV transmitted horizontally?
Shed in saliva + feces
Close contact
How are baby chickens protected from ALV?
Hen can pass antibodies to virus to the yolk sac
Provides passive immunity
What causes cancer to form in ALV infections?
Proviral insertion into B cells close to c-myc gene
= B cell transformation
Lymphoid leukosis
What is lymphoid leukosis?
A clonal malignancy of B cells
Where does B cell transformation occur with ALV infections?
In the intact bursa 4 to 8 weeks after infection
When is there an enhanced lyphoid leukosis?
Chickens coinfected with Marek’s disease
How does subclinical ALV infections present?
Depressed egg production
What clinical symptoms are seen with ALV infections?
Loss of appetite
Weakness
Diarrhea
Dehydration
Emaciation
Enlarged bursa + liver
Pale wattles
Osteopetrosis
Where are nodular tumors commonly seen with ALV infections?
Liver
Spleen
Bursa
What occurs secondary to B cell infection of ALV?
Immunocompromise
Respiratory disease
BLV - Envelope proteins
gp 51 + 30
BLV - Capsid proteins
p24
What ensymes are present in BLV?
RT
Integrase
Protease
tax
rex
What is the importance of tax + rex?
Essential for oncogenesis
Interact with cell cycle regulatory factors result in cell cylce dysregulation + transformation
Who are the common hosts of BLV?
Cattle
Dairy > Beef