Polyoma Virus Flashcards
Polyoma virus family
papovaviridae
morphology of polyoma virus
circular ds DNA genome of 5-8 kbp
non-enveloped icosahedral capsule
polyoma viruses, as with papilloma viruses, can transform non-permissive cells and lead to tumor formation
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In permissive cells, polyoma viruses
replication and assembly of progeny occurs in the nucleus.
virions are released by cell lysis
In non-permissive cells
infection leads to transformation. polyoma virus genome integrates into host chromosomes
Describe the three T antigens of the polyoma virus
They are needed to initiate DNA replication
Small T and Large T antigens are necessary for what
to immortalize cells
Small T and Middle T needed to
transform cells….
The path goes primary cell, immortalized cell, transformed cell (these types of cells grow uninhibited by growth factors)
Two known human polyoma viruses
BK and JC
KNow that BK and JC are basically found in all humans but are NOT oncogenic
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Initial replication of BK and JC occurs where
site of infection, resp or GI tract
After initial infection by BK or JC, what happens
viremia and passage to kidney lung and brain
The virus persistently affects the kidney
BK and JC are only problematic in who?
Immunodeficient hosts
JC is the causative agent of
Progressive multifocal Leukoencephalopathy
PML is what
Progressive multifocal Leukoencephalopathy
a demyelinating disease of the CNS.
Probably due to reactivated JC virus which makes its way to the cns and infects/lyses oligodendrocytes
