CNS Viruses -- Polyomavirus Flashcards
Structure of Polyomavirus?
Circular dsDNA genome, nonenveloped icosahedral capsid
How can polyomavirus cause tumors?
Transform non-permissive cells into immortalized/tumorigenic cells
What two viruses do you need to know?
BK and JC
Are BK and JC oncogenic?
No
In what pt. population do polyomaviruses cause problems?
Transplant and AIDS patients
Where does BK cause problems?
Urine
Where does JC cause problems?
CNS –> Progressive multifocal leukodystrophy
What’s the pathophys of PML?
Reactivated JC virus in oligodendrocytes causes lysis –> demyelination
For dx of JC, should you culture?
No
How do you dx JC?
MRI detection of white matter lesions; PCR amplification
Is there virus-specific Rx for PML?
No
How do you manage PML? Prognosis?
Adjust immunosupp. in transplant pts; adjust HAART in AIDS pts; BAD PROG
Where does replication in permissive cells take place?
Nucleus
What do early genes encode? Purpose?
T Antigens; Initiate DNA replication, responsible for transformation (analogous to E6 and E7 of papilloma viruses)
Which T antigens are necessary to immortalize cells?
Small and large
