Virology Exam 2 - Retroviruses Flashcards
importance of antigenic variation
high mutation rate
reverse transcriptase
allows reverse transcription (ssRNA to dsDNA) so DNA can enter nucleus
importance of chromosomal integration of viral genome
dsDNA integrates into host cell DNA via integrase and becomes provirus (proviral DNA)
source of recombination viral RNA –> proviral DNA –> endogenous retrovirus
viral persistence
infect WBC and enter bone marrow
infect progenitor cells and their progeny so virus is already in their genome
importance of oncogenesis
tumor-promoting
slow c-onc provirus randomly inserted, normal gene, under control
fast v-onc replication competent, mutated, no longer under control
Retroviridae
SHAPE
ENVELOPED/NON-ENVELOPED
DNA/RNA
icosahedral
enveloped with glycoprotein spikes
diploid +ssRNA
contains gag, pol, env, LTR, oncogenes
endogenization
provirus integration into the germline
vertical transmission
Bovine Leukemia/Leukosis Virus
HOST
DISEASE
PATHOGENESIS
bovine, experimentally sheep
persistent leukosis (PL), lymphoma/lymphosarcoma (LS), inapparent infection
B lymphocytes
what are the four Lentiviruses in the family Retroviridae
caprine arthritis encephalitis virus
ovine progressive pneumonia virus
equine infectious anemia
FIV
significance of lentiviruses
long incubation period/slow onset
long period to seroconversion
persistent infection
tropism of immune cells
significance of lentiviruses
long incubation period/slow onset
long period to seroconversion
persistent infection
tropism of immune cells
Caprine Arthritis Encephalitis Virus
HOST
DISEASE
goats, sheep
encephalitis (goats 2-4 mo)
chronic arthritis (adults)
“hard-bag” aka lymphocytic mastitis
progressive pneumonia
ovine progressive pneumonia virus
HOST
DISEASE
goats, sheep
pneumonia, wasting, demyelinating leukoencephalomyelitis , “hard-bag”
equine infectious anemia
HOST
DISEASE
TRANSMISSION
PATHOGENESIS
DIAGNOSTIC
CONTROL
equine
swamp fever, anemia, thrombocytopenia, petechial hemorrhage
biting insects, iatrogenic, vertical
tropism for macrophages, immune-mediated lysis of RBC, immune-complex
Coggins test/ELISA - detect Ab
reportable, fed-regulated
feline leukemia virus (FeLV)
HOST
STRAINS
DISEASE
OUTCOMES OF EXPOSURE
CONTROL
DIAGNOSTICS
feline - KITTENS
A (only horizontally infectious strain; exogenous)
B (recombinant strain, endogenous virus must combine with exogenous A)
neoplasia, immune mediated complexes, antibody dependent cytotoxicity, secondary infections w/ FIP, toxoplasmosis, mycoplasma,
Aspergillus sp.
abortive, regressive, progressive
fading kitten syndrome
SNAP to detect Ag
