Transcript 1956 adenovirus

Adenoviridae
Molecular Virology
HISTORY
 first isolated in 1953 (Rowe, et al. (1953),
Proc. Soc. Exp. Biol. Med. 84:570–573)
from tonsils and adenoids of children
passage
normal cell culture
cytopathic effect
virions
 similar viral agents were isolated from febrile military personnel with
respiratory illnesses
 adenoid degeneration (AD), adenoid-pharyngeal conjunctival (APC), and
acute respiratory disease (ARD) agents
 1956  ADENOVIRUS
TAXONOMY
GROUP
FAMILY
GENUS
Group I dsDNA
Adenoviridae (Greek, adenos, “gland”)
Mastadenovirus (Greek, mastos, “breast”)
Aviadenovirus (Latin, avis, “bird”)
Atadenovirus (English, adenine and thymine)
Siadenovirus (English, sialidase)
Ichtadenovirus (Greek, ichthys, “fish”)
TYPE SPECIES
Sturgeon Adv A
Frog Adv
Fowl Adv A
Ovine Adv D
Human Adv C
CLASSIFICATION SCHEMES FOR HUMAN ADENOVIRUS
(MASTADENOVIRUS H)
Subgroup
(species)
A
B
C
a
Hemagglutination groups
Serotypes
IV
(little or no agglutination)
I
(complete agglutination of monkey
RBCs)
III
(partial agglutination of rat RBCs)
12, 18, 31
D
II
(complete agglutination of rat RBCs)
E
F
III
III
Percent of GC in
DNA
48-49
3, 7, 11, 14, 16, 21,
34, 35, 50
50-52
1, 2, 5, 6
57-59
8-10, 13, 15, 17, 19,
20, 22-30, 36-39,
42-49, 51
4a
40, 41
57-61
57-59
The genome sequence of Ad4, the one member of subgroup E, is related to Ads of subgroup B
Knipe and Howley. Field’s Virology. 5th ed.
GENOME
 linear dsDNA; 30-36 Kb
 inverted terminal repeat (ITR) sequences at 3’-end; 30-200 bp
 linear DNA forms a loop due to terminal protein (covalently linked to each 5’
end) and terminal base pairing
 all genes are transcribed by host RNA pol II except VA gene which
is transcribed by RNA pol III
 mRNAs are polycistronic and are differentiated by alternative splicing and
use of different poly(A) sites
STRUCTURE
 non-enveloped, icosahedral capsid; 90-120 nm
 20 equilateral triangular faces, 12 vertices
 each face has 12 identical hexons and each vertex has 1 penton;
 each penton is attached to a fiber protein
 12 x 20 = 240 hexons; also 12 pentons
 total of 252 capsomers
CAPSID
Protein II (hexon monomer)
- structural
- neutralizing Abs directed
against the ε epitope
- type specific Ag sites
CAPSID
Protein II
Protein III (penton base)
- penetration
CAPSID
Protein II
Protein III
Protein IIIa
- penetration
CAPSID
Protein II
Protein III
Protein IIIa
Protein IV (fiber protein)
- receptor attachment
- hemagglutination
- type-specific and some
species-specific Ag sites
CAPSID
Protein II
Protein III
Protein IIIa
Protein IV
Protein VI
- hexon minor polypeptide
- stability/particle assembly
CAPSID
Protein II
Protein III
Protein IIIa
Protein IV
Protein VI
Protein VIII
- hexon minor polypeptide
- stability/particle assembly
CAPSID
Protein II
Protein III
Protein IIIa
Protein IV
Protein VI
Protein VIII
Protein IX
- hexon minor polypeptide
- stability/particle assembly
CAPSID
Protein II
Protein III
Protein IIIa
Protein IV
Protein VI
Protein VIII
Protein IX
- hexon minor polypeptide
- stability/particle assembly
CORE
Protein V
- links DNA to penton base
- histone-like, packaging
CAPSID
Protein II
Protein III
Protein IIIa
Protein IV
Protein VI
Protein VIII
Protein IX
- hexon minor polypeptide
- stability/particle assembly
CORE
Protein V
- links DNA to penton base
- histone-like, packaging
Protein VII
- histone-like, packaging
CAPSID
Protein II
Protein III
Protein IIIa
Protein IV
Protein VI
Protein VIII
Protein IX
- hexon minor polypeptide
- stability/particle assembly
CORE
Protein V
- links DNA to penton base
- histone-like, packaging
Protein VII
Protein X (µ)
- packaging
CAPSID
Protein II
Protein III
Protein IIIa
Protein IV
Protein VI
Protein VIII
Protein IX
- hexon minor polypeptide
- stability/particle assembly
CORE
Protein V
- links DNA to penton base
- histone-like, packaging
Protein VII
Protein X (µ)
55kD Terminal protein
- genomic replication
CAPSID
Protein II
Protein III
Protein IIIa
Protein IV
Protein VI
Protein VIII
Protein IX
- hexon minor polypeptide
- stability/particle assembly
CORE
Protein V
- links DNA to penton base
- histone-like, packaging
Protein VII
Protein X
55kD Terminal protein
dsDNA
ATTACHMENT & ENTRY
CD46 for Human Adv subgroup B
Disassembly of proteins IIIa, IV, III, VIII
Intracellular reducing environment
activates viral protease and
cleavage of protein VI that links
the viral core to capsid
EARLY TRANSCRIPTION & TRANSLATION
<8 hr
GENOME REPLICATION
LATE TRANSCRIPTION & TRANSLATION
>12 hr
ASSEMBLY & RELEASE
100K protein facilitates folding and
assembly of hexon trimers
Protein VI stabilizes capsid and facilitates
hexon importation
IVa2, L1 52/55K, L4 22kD promote
viral DNA packaging
Cleavage of precursors of VI, VII, VIII,
X by viral protease
Viral escape and spread of progeny virus by:
1) L3 protease cleavage of cellular cytokeratin
2) ADP kills cells
3) free fiber trimers released from infected cells
interfere CAR oligomerization at tight junctions
Immune Evasion
1. Inhibition of IFN functions
- VA-RNA and E1A – binds to PKR
2. Inhibition of TNF and Fas-mediated
apoptosis
- E1B19K, E314.7, E310.4K/14.5K
3. Downregulation of surface class I MHC
- E3gp19, E1A – retention of MHC I in ER
E3 proteins and their functions
Knipe and Howley. Field’s Virology. 5th ed.
E4 proteins and their functions
E4
orf6/7
orf6
orf4
orf3
Modulates E2F
orf2
?
Interacts with
E1B 55K
facilitating RNA
metabolism
Binds to DNA PK
Interacts with
E1B 55K
Relocates nuclear pods
orf1
Facilitates
transformation
Inhibits E1A
activation of E2F
Binds to DNA PK
Journal of General Virology (2000), 81, 2573–2604
Journal of General Virology (2000), 81, 2573–2604
Oncogenic potential of human adenoviruses
Subgroup
(species)
A
B
C
D
E
F
Tumor in animals
High, within 4 months
Moderate, within 4 to 8 months
Low or none
Low or none
(mammary tumors, within 3 to 5 months)
Low or none
Unknown
Transformation
in tissue culture
+
+
+
+
+
Knipe and Howley. 2007. Field’s Virology. 5th ed.
CLINICAL FEATURES OF DISEASE
meningoencephalitis
•
ENTRY
OCULAR INFECTIONS
conjunctivitis
keratoconjunctivitis
myocarditis
SPREAD
RESPIRATORY INFECTIONS
pharyngitis
pertussus
pneumonia
acute respiratory disease
•
•
GASTROINTESTINAL INFECTIONS
gastroenteritis
hepatitis
hemorrhagic cystitis
•
Adenovirus diseases, associated serotypes, hosts and clinical specimens for diagnosis
Zuckerman, et al. 2009. Principles and Practice of Clinical Virology. 6th ed.
Diseases of Domestic Animals Associated with Adenoviruses
NUMBER
OF
ANIMAL SPECIES SEROTYPES DISEASE
Dogs
2
Infectious canine hepatitis (Canine Adv 1)
Infectious canine tracheobronchitis (Canine Adv 2)
Horses
2
Usually asymptomatic or mild respiratory disease. Bronchopneumonia
and generalized diseases in foals with primary severe combined
immunodeficiency disease
Cattle
10
Usually asymptomatic or mild respiratory disease
Swine
4
Usually asymptomatic or mild respiratory disease
Sheep
6
Usually asymptomatic or mild respiratory disease
Goats
2
Usually asymptomatic or mild respiratory disease
Deer
1
Pulmonary edema, hemorrhage, vasculitis
Rabbits
1
Diarrhea
Chickens
12
Egg drop syndrome, inclusion body hepatitis
Turkeys and
3
Hemorrhagic enteritis (turkey); marble spleen disease (pheasant); egg
pheasants
drop syndrome in both
Quail
1
Bronchitis
Duck
2
Rarely, duck hepatitis
Geese
3
Isolated from liver, intestines
Murphy, et al. Veterinary Virology. 3rd ed.
DIAGNOSIS
1. DIRECT METHODS
a. Viral isolation – human epithelial cell lines
b. Histopathology – enlarged nuclei with basophilic inclusions
c. Direct antigen detection
i.
IFA
ii. EIA
iii. Immunochromatography
iv. IHC
d. Direct particle detection
i.
EM – acute gastroenteritis
e. Direct genome detection
i.
PCR, real-time PCR
2. INDIRECT METHODS
a. Serology – IgM/IgG
USE OF ADENOVIRUSES AS:
I. GENE THERAPY VECTORS
- gene to correct genetic defect
II. CANCER THERAPY VECTORS
- gene induces cell death
III. VACCINE VECTORS
- gene is antigen
http://en.wikipedia.org/wiki/Image:Gene_therapy.jpg
Types of Adenovirus Vectors
1) Replication-defective vectors
- one or more viral genes deleted
2) Replication-competent vectors
Replication-defective vectors
FIRST GENERATION VECTORS
-E1 deleted
SECOND GENERATION VECTOS
-E1, E2, E4 deleted
-
helper-dependent vector
Knipe and Howley. Field’s Virology. 5th ed.
Replication-competent vectors
Knipe and Howley. Field’s Virology. 5th ed.
ADENOVIRUSES AS VECTORS FOR
VACCINATION AND GENE THERAPHY
Advantages
 can be grown to produce
stable, high titer stocks;
 can infect broad range of
tissues including
nondividing cells;
 rarely integrate into the
host chromosome
Disadvantages
 duration of the expression
of the transgene will be
limited
 chances of the vector to
bind to non-target cells
 size of foreign gene is
limited
Journal of General Virology (2000), 81, 2573–2604
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