HPV and HPolyV Flashcards
structure of Human polyoma virus and Human papilloma virus
naked icosahedral
circular dsDNA
human polyomaviruses are usually seen in….
immunocompromised:
organ transplantation/HIV infection
route of human polyoma virus transmission
enters through respiratory tract; can get into blood and remain latent until reactivated by immunocompromisation
reactivation of JC virus can cause….
reactivation is most common in…
progressive multifocal leukoencephalopathy(PML)
- transforms astrocytes
- kills oligodendrocytes
- demyelinating lesions
common in CD4<50; AIDS pts
reactivation of BK virus can cause….
reactivation is most common in…
polyomavirus-associated nephropathy after solid organ transplant
hemorrhagic cystitis after stem cell transplant
HPV capsid proteins
L1, L2
genes of HPV genome
early: E1-8
late: L1,L2
long control region(LCR)
transmission of HPV
vaginal/anal/oral sex
mother»newborn
pathogenesis of HPV
virus gets into basal layer of stratified epithelium via micro-tears
L2-DNA complex moves into nucleus as episome
E6/E7 induce cell proliferation by inhibiting p53/Rb
Viruses are assembled by the time cells reach cornosum layer and are shed at surface
how does carcinogenesis occur in HPV?
integration into host genome can cause loss of E2 which regulates E6/E7 expression
if E2 is lost, E6/E7 will constitutively inhibit p53/Rb and cause tumor formation
HPV 6,11 primarily cause
mucosal warts/cutaneous infection
recurrent respiratory papillomatosis
HPV mucosal warts can progress to….
low grade CIN/AIN(cutaneous/anal neoplasias)
regress in most adults w/in 5 years
manifestation of HPV involving recurrent laryngeal tumors, hoarseness, stridor, respiratory distress
can be child onset from birth canal
recurrent respiratory papillomatosis
most common HPV types causing cancer
HPV 16 and 18
more likely a resistant strain if same HPV is detecte 2x in 6-12 mo.
high risk HPV types
16,18,31,33,45,62,58
