Papillomaviruses

Provide a general description of papillomaviruses

• 100 different HPV

• Consequences range from no symptoms, warts, carcinoma

• Nonenveloped 52-55nm diameter virion

• L1 = major virion protein, L2 = minor virion protein

• Closed circular double stranded DNA, 8-8kbp

• all ORFs are encoded by one strand of the DNA

Describe the infection rates of HPV

• ~20mil infected with HPV at all times

• >50 sexually active acquire genital HPV at least once

• By age 50, 80% of women will have acquired HPV

• ~6.2mil Americans diagnosed with HPV every year

• Spread primarily through genital contact

• Most don’t show symptoms; infected persons unaware yet can transmit the virus

• Vaccine, Gardasil, protects against HPV6, 11, 16, 18, which together cause 70% of cervical cancer and 90% of genital warts. Made against VLPs

Describe the levels of the cells of PPV

• Mature virions shred

• Mature virions

• Virion assembly

  • Late capsid proteins L2 and L1

  • Vegetable DNA simplification

  • High levels of early an differentiation dependent proteins, notably E4

  • Koilocytosis of productive keratinocytes

• Differentiation dependent E6 & E7 proteins

  • Early proteins E1, E2, E4 & E5

• Possible alt site of infection

  • Immediate early proteins E1, E2 & E5

• Primary infection

  • Establishment replication

  • Immediate early proteins E1, E2 & E5

What does PPV DNA replication require

• E1 protein - Helicase

• E2 protein

• Ori

• Permissive cell

• E2 binds ori and binds E1

• E2 binds the cellular replication apparatus and brings it to the viral ori