adeno,parvo,polyoma virus

Adenovirus, parvovirus, polyomavirus

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Adenovirus


From Medical Microbiology, 5th ed., Murray, Rosenthal & Pfaller, Mosby Inc., 2005, Fig. 53-1.

Adenovirus Structure


E1

E2 E4

E3Late genes

Adenovirus Genome

36 kb linear ds DNA

Early genes for host and viral transcription control, viral DNA replication

Late genes for virion structure


(From Fields Virology, 4th ed, Knipe & Howley, eds, Lippincott Williams & Wilkins, 2001, Fig. 67-5.)

Adenovirus replication cycle


Adenovirus diseases


From Medical Microbiology, 5th ed., Murray, Rosenthal & Pfaller, Mosby Inc., 2005,, Fig. 50-4.

Adenovirus pathogenesis


Summary: adenovirus

• Structure– Medium sized (36 kb) dsDNA genome, naked capsid

• Pathogenesis– respiratory or fecal oral transmission– replication in nucleus; moderately host dependent– local spread; viremia– cellular and humoral immunity important; virus encodes

countermeasures against MHC I expression and apoptosis– direct cell damage from replication; respiratory illness,

conjunctivitis, gastroenteritis, cystitis• Diagnosis

– culture, viral antigen detection• Treatment/prevention

– live military vaccinewww.freelivedoctor.com

Parvovirus


Parvovirus structure


Parvovirus Genome

Rep Cap

5 kb ssDNA, inverted terminal repeats (ITR)

Rep gene required for DNA replication

Cap gene encodes capsid proteins

ITR ITR


Autonomous parvovirus replication


Helper dependent parvovirus (AAV) replication

AAV DNA integrates into

chromosome 19

Infection without adenovirus

Infection with adenovirus

Superinfect with

adenovirus

Lytic replication


Parvovirus pathogenesis


Parvovirus• Structure

– Small (5 kb) linear ssDNA genome, naked capsid• Pathogenesis

– respiratory transmission– replication in nucleus, very host dependent, needs S phase

cells or helper virus– viremia– antibody important in immunity– targets erythroid lineage cells; fifth disease (symptoms

immunological); transient aplastic crisis; hydrops fetalis• Diagnosis

– serology, viral nucleic acid• Treatment/prevention

– none


Polyomavirus


Polyomavirus genome


Replication cycle of polyomaviruses. Steps in the replication cycle are indicated by numbers as follows: 1, adsorption of virions to the cell surface; 2, entry by endocytosis; 3, transport to the cell nucleus (route and mechanism not yet known); 4, uncoating; 5, transcription to produce early region mRNAs; 6, translation to produce early proteins (T antigens); 7, viral DNA replication; 8, transcription to produce late region mRNAs; 9, translation to produce late proteins (capsid proteins); 10, assembly of progeny virions in the nucleus; 11, entry of virions into cytoplasmic vesicles (mechanism unknown); 12, release of virions from the cell by fusion of membrane vesicles with the plasma membrane; 13, released virion.

Polyomavirus replication


Polyomavirus pathogenesis


Polyomavirus

• Structure– Small (5 kb) circular dsDNA genome, naked capsid

• Pathogenesis– respiratory transmission– replication in nucleus; very host dependent– viremia– persistence in kidneys; reactivation with immune compromise– inapparent infection; hemorrhagic cystitis; PML

• Diagnosis– viral nucleic acid

• Treatment/prevention– cidofovir ?


adeno,parvo,polyoma virus

Documents

polyomavirus replication

adenovirus replication

adenovirus pathogenesis

adenovirus lytic replication

parvovirus pathogenesis

parvovirus genome

adenovirus infection

polyomavirus pathogenesis