Papovaviruses

Question 1

Papova =

Answer 1

Papova = Papilloma, Polyoma and Simian vacuolating viruses (SV-40)

Question 2

Polyomaviruses: includes

Answer 2

Polyomaviruses: includes SV-40

Question 3

Polyomaviruses: Properties

Answer 3

– circular dsDNA, naked, nuclear replication

Question 4

Polyomaviruses: Genome

Answer 4

– early region and late region, bi-directional transcription

Question 5

Polyomaviruses: Gene products

Answer 5

• large and small T antigens (early) and VP1-3 and agnoprotein (late)

Question 6

Polyomaviruses: Large T antigen

Answer 6

Large T antigen – DNA binding protein, helicase activity, tumor suppressor protein interaction, genomic instability

Question 7

Polyomaviruses: Small t antigen

Answer 7

Small t antigen – associates with protein phosphatase 2A

Question 8

Polyomaviruses: JC virus

Answer 8

JC virus - occurs with immunodeficiency
Pathogenesis – respiratory tract → B cells, brain, kidney → progressive multifocal encephalopathy (demyelination), targets oligodendrocytes → enlarged nuclei (ballooned) with viral inclusions
Presentation – impaired speech and vision, paralysis, mental deterioration

Question 9

Polyomaviruses: BK virus

Answer 9

BK virus- occurs with immunodeficiency
Pathogenesis – similar to JCV → virus persists in kidney → shed into urine → renal disease, hemorrhagic cystitis
Polyoma associated nephropathy – renal transplant pts, reactivation of BKV, affects epithelia of tubules and collecting duct

Question 10

Polyomaviruses: SV-40

Answer 10

SV-40 - contaminated polio vaccines

Question 11

Papillomavirus:

Properties

Answer 11

– naked, circular dsDNA, icosahedral, nuclear replication

Question 12

Papillomavirus: Types

Answer 12

– cutaneous, mucosal – high risk (16,18) and low risk (6,11), only infect surface squamous epithelia

Question 13

Papillomavirus: Replication

Answer 13

Replication – infection of proliferating basal cells → amplification of viral genome in differentiation epithelia → lytic cycle, shedding

Question 14

Papillomavirus: Immune evasion

Answer 14

Immune evasion – no blood phase, no replication in APCs, keratinocytes are not lysed, E6,7 is limited and restricted to the nucleus, capsid protein production is delayed

Question 15

Papillomavirus: Condylomata acuminata

Answer 15

Condylomata acuminata – anogenital warts, HPV 6,11

Question 16

Papillomavirus: Common warts

Answer 16

Common warts – verruca vulgaris, HPV 2,4

Question 17

Papillomavirus: Plantar warts

Answer 17

Plantar warts – verruca plantaris, HPV1,2,4

Question 18

Papillomavirus: Cervical cancer

Answer 18

Cervical cancer – HPV 16,18, most common cancer in women, slow history, integration into host genome at E2 (E6,7 repressor), express E6,7 to prevent apoptosis
Vaccine – contains L1 protein from HPV 16,18,6,11