Adenovirus

Question 1

Aenovirus (general)

Answer 1

• does not cause cancer despite interference with cell cycle
• acute respiratory disease in military recruits
• transcription occurs in host nucleus using host DdRp (DNA-dependent RNA polymerase)
• early mRNA transcripts encode regulatory proteins and DNA replication proteins
• late mRNA encode structural proteins
• stimulate cell-cycle progression for DNA replication assistance host proteins
• key virus in the discovery of mRNA splicing

Question 2

Adenovirus Stx & Genome

Answer 2

• large DNA virus (>30kb) icosahedral
• hexon and penton (base for fiber-attachment protein) capsid protein
• non-enveloped, linear dsDNA with 3 phases of gene expression:
• immediate early- E1A activates transcription and S phase induction. E1B - block apoptosis (p53 inhibitor)
• early - E2 DNA replication, E3 immune evasion, E4 transcription regulation
• late - blocks host mRNAs)

Question 3

Adenovirus replication

Answer 3

• Fiber - CAR attchment -> clathrin endocytosis
• endosome escape (Protein VI)
• microtubule to nucleus
• gene expression
• DNA replication - inverted terminal repeasts as replication origin, immediate-early genes
• nucleus assembly and cell lysis exit

Question 4

Adenovirus pathogenesis

Answer 4

• oral or respiratory ingestion (contact)
• primary replication in respiratory or GI epithelium
• continguous spread (rare hematogenous dissemination)

Question 5

Adenovirus clinical manifestations

Answer 5

• GUAPC - miliraty camp (close quarters)
• upper respiratory infection (common cold)
• conjunctivities
• pharyngitis
• ARD (acute respiratory disease)
• gastroenteritis

Question 6

List Hallmarks of Oncogenic Transformation

Answer 6

• loss of anchorage dependence
• loss of contact inhibition
• colony formation in semi-solid media
• decrease requirement for growth factors
• formation of tumors in immunocompromised animals
• *E1A / E1B adenovirus proteins are oncoproteins. E1A binds to Rb liberating E2F/transcription factor (S phase), E1B inactivates p53