Family: Adenoviridae Flashcards
Where were Adenoviridae first recovered from?
human adenoid tissue
What are the 5 genera of Adenoviridae?
- Mastadenovirus
- Aviadenovirus
- Atadenovirus
- Ichtadenovirus
- Siadenovirus
What is the structure of Adenovirus like?
non-enveloped, hexagonal capsid with icosahedral symmetry with fibers protruding from each penton base
How do Mastadenovirus and Aviadenovirus compare in structure?
M = one fiber gene
A = two fiber genes
What is the genome of Adenoviridae like? Where does it replicate?
single linear dsDNA with inverted terminal repeats
in the nucleus
What are the functions of the 7 polypeptides on the capsid of Adenoviridae?
II - hexon protein
III - penton base
IIIa - link adjacent faces
IV - fiber
VI, VIII, IX - stabilize hexon capsomere lattice
What are the functions of the 4 polypeptides found on the core of Adenoviridae?
V - bridge between penton and core
VII - major core protein
TP - attach viral genome to nuclear matric, circularize viral DNA, DNA replication primer
Mu - unknown
Adenoviridae classification:
What determines the target cell specificity and attachment of Adenoviruses? How is their replication different?
fiber proteins
- early and late phases —> error-prone
- release viral capsid in cytosol then transferred into nucleus
What are the 6 steps of Adenovirus replication?
- virus attached to host receptors through the fiber glycoproteins and is endocytosed into vesicles
- disruption of endosome releases viral capsid in the cytosol and is released into the nucleus
- transcription of early genes (E genes) and replication of DNA in nucleus
- transcription of late genes (L genes), mostly encoding for structural proteins
- assembly of new virions in nucleus
- virions release by lysis
What are the 3 types of Adenovirus infection? Where is it common to see each?
- LYTIC: results in cell death —> mucoepithelial cells
- LATENT/OCCULT: virus remains in host —> lymphoid tissue
- ONCOGENIC TRANSFORMATION: uncontrolled cell growth and replication —> group A viruses in hamsters
What causes infectious canine hepatitis? How was it distinguished from canine distemper?
(Rubarth’s Disease)
Canine Adenovirus-1 and 2
inoculation into ferret —> resistant (only infects domestic and wild dogs)
What are 7 clinical signs of infectious canine hepatitis?
- pyrexia
- nausea
- vomiting
- loss of appetite
- jaundice
- light-colored stool
- stomach enlargement
What are 4 common postmortem findings in canine infectious hepatitis?
- vascular endothelial damage leads to petechial hemorrhage on mucous membranes and skin
- swollen, mottled liver with rounded, lobular edges*
- gall bladder edema*
- intranuclear inclusion bodies in hepatocytes
What is the pathogenesis of Canine Adenovirus-1, causing infectious hepatitis?
- oro-nasal infection
- replication in tonsils, Peyer’s patches, and other lymphatic tissues
- viremia allows for replication in vascular cells in many organs —> hepatocytes, endothelial cells of renal glomeruli, cornea, uvea