Human Parvoviruses

Kevin E Brown

Immunisation and Diagnosis Unit

Virus Reference Department

Centre for Infections

ParvovirusesSmall 22-24 nm non-enveloped4 - 5.5 kb ss DNA genome with ITRs at 5’

and 3’ endsEncode no polymeraseDependant on cellular/other viral proteins

for DNA replication2 large ORF

NS (or Rep) proteins VP (or Cap) proteins

ClassificationTwo subfamilies – host range

Densovirinae – insectsParvovirinae – vertebrates

Autonomous/dependant replication

+ or – strand packagingIdentical or different 5’ and 3’

ITRs1, 2 or 3 promoters

Sequence pyhlogeny

D e n so v irus

Ite ra v irus

B re v id e n so v irus

P e fun d en sov irus

D e n sov irin ae(S u b fa m ily)

M V M

C a n ine p a rvo v irusC P V

P o rc ine p a rvo v irusP P V

Parvovirus

A A V s-1 -?

G o ose pa rvov irusG P V

A v ia n A A VA A A V

Dependovirus

P a rvov irus B 19B 1 9V

S im ian p a rvo v irusS P V

P m P V

Erythrovirus

B o v in e pa rvov irusB P V

M inute viru s of canine sM V C

Bocavirus

A le u tio n d ise a se(m in ks )

Am dovirus

Parvovirinae(S u b fa m ily)

Parvoviridae(F a m ily )

Parvovirus B19• First identified in 1974 (CPHL, London)• ~ 22 nm icosahedral virion• Linear single stranded DNA

• ~ 5600 nucleotides• Long (383nt) terminal hairpin seq• Complex transcription map

• Single promoter (p6)

• 1 non-spliced non-structural protein

• 2 capsid proteins (VP1 & VP2) -alt splicing

• Small proteins of unknown function

• VP2 self assembles to form VLP

• Erythrotropic• Does not grow in standard tissue culture• Replicates in erythroid progenitors• Rare cell lines (UT7/Epo; KU812Ep6)

Servant et al. J. Virol 2002

Phylogenetic tree of VP1u region

V9

A6

Panel Dates No B19 pos Variant

A HIV patients

France

1992-1997 21 1 1

Type 3

5% Servant, J. Virol 2002

B Fetal hydrops

France

1995-1997 73 16 0 0

D B19 Ag positive

France

1972-1999 87 87 1

Type 3

1%

E B19-like symptoms

France

1999-2001 633 88 9

Type 2 & 3

10%

C B19-like symptoms

USA

270 204 0 0

Blood donors

UK

1999-2001 1000 9 0/4 Candotti, J.Virol 2004

Blood donors

Ghana

1999-2001 1000 13 12/12

Type 3

100%

B19-like symptoms

Brazil

2003-2005 69 12 7

6 type 3

1 type 2

58% Sanabani,

J. Clin Micro 2006

Tissues

Finland

523 190 58*

Type 2

11% Norja, PNAS 2006

Prevalence of variant B19 in different groups

* Only detected in those born before 1973

• 1st identified in a IVDU• Fever, arthralgia,

meningism• Acute sample only• Lost to follow up

• Closest sequence• Putative Erythroviruses• Chipmunk

Parv4 DNA

• Typical parvovirus features• Incomplete hairpin sequence • Gap between NS and capsid• VP1 ~ 100 kDa• No 11 kDa or 7.5kDa ORFs

Prevalence of Parv4 DNAby PCR (NIH data)

Samples N HP4-F/R

(NS)

HP4-2

(Capsid)

HP4-3

(Capsid)

Clinical samples 262 0 1 3

HAA samples 26 0 2 1

Liver samples 17 0 0 0

Arthropathy 20 0 20 NT

HIV 12 NT NT 1

Blood donors 20 0 0 0

Plasma pools 62 0 2 1

German pools 6 0 0 0

Blood donors from Los Angeles area summer 2005

300 pools of 16

29 positives (9.6% or 0.6% if divided by 16).

200 single donations

4 positives (2%)

Subjects with symptoms of acute viral infection or highly exposed (MSM, IDU)

16/195 subjects positive (85)

1 PARV5, PARV4

Increasing prevalence in symptomatic/exposed subjects may reflect pathogenic viral infection OR higher exposure to blood borne viruses (e.g. like GBV-C)

Prevalence of PARV4 virus using nested PCR

10 20 30 40 50 60 70 80 90 100---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+gttgatggccctgtggttagCACCCAGCATCAAGAAGCTTTGCAGACAAGAATAACCATGTTTCAGTTTCAGAGAATGGTTCCGGATGGCTTAGCTCCAC PARV4-Cutter pool-1991

........y..................................G........................................................ Poolx16 24/29

........y........................................................................................... Poolx16 2/29

........y..................................R........................................................ Poolx16 1/29

........y........................T.........G........................................................ Poolx16 1/29

........y..................................G................................................R....... Poolx16 1/29

........y..................................G........................................................ Neat 3/4

........y..................................G.....................................T.................. Neat 1/4

........y..................................G........................................................ Option 7/16

........y........................................................................................... Option 3/16

........y........................................................................................... Option 1/16

........y..............................................T............................................ Option 1/16

........y................R.................G........................................................ Option 1/16

........y..................................G...R.................................................... Option 1/16

........y.............................C....G........................................................ Option 1/16

........y..............T........G......C..................................G........C...........C..T. Option 1/16

--......T..............T........G......C..................................G........C...........C..T. PARV5-Cutter-1991

110 120 130 140 150 160---------+---------+---------+---------+---------+---------+-TTCCTGAAGAGGAAGTGAGAAGCTTTTTTAAGCTAGgtgaacaggaactgaatatgaaagg PARV4-Cutter-1991

............................................................. Poolx16 24/29

............................................................. Poolx16 2/29

............................................................. Poolx16 1/29

............................................................. Poolx16 1/29

............................................................. Poolx16 1/29

............................................................. Neat 3/4

............................................................. Neat 1/4

............................................................. Option 7/15

............................................................. Option 3/15

...............................A............................. Option 1/15

............................................................. Option 1/15

............................................................. Option 1/15

............................................................. Option 1/15

............................................................. Option 1/15

.C....................T...........T.......................... Option 1/15

.C....................T...........T.......................... PARV5-Cutter-1991

Genetic variation among PARV4

Parv4 DNA

VP2 expression• Bacteria

• 60 kDa

• Baculovirus• VLP• No HA

• ELISA developed• Indirect format

Seroprevalence of Parv4<6 months 6 months-5 6-10 11-15 >16

Washington DC

Pos 15 27 23 28 9

Equiv 2 6 3 0 0

Neg 7 7 4 0 0

Total 24 40 30 28 9

Vietnam

Pos 10 12 9 12 1

Equiv 5 3 2 1 0

Neg 2 7 2 1 0

Total 17 22 13 14 1

% Positive 73.5% 62.9% 74.4% 95% 100%

• Pooled NPA secretions • 48 samples• 38/48 pediatric patients

• 378 NPA samples• Culture negative• 7/266 pediatric patients• 0/112 adult patients

• 540 samples hospitalized peds• 3.1% pos• Increased in winter months

• Closest sequence• Bovine parvovirus• CPV type 1 (MVC)

Human parvoviruses• Parvovirus B19 (B19V) – type member of Erythroviruses

• 3 different genotypes now recognized• No evidence for different serotypes• Highly erythrotropic• Detection of DNA in blood and tissues for years following acute

infection• No evidence of reactivation/integration

• Parv4/5 is a new member of the Parvovidae• Sequences are uncommon in blood and blood products• No culture method available • VLP can be expressed

• Do not resemble B19V• Do not HA

• Parv4 Ab common in children/adults

• Human bocavirus in respiratory secretions of children < 5• Prevalence in other tissues/age groups• VLP can be expressed

• Adeno-associated viruses – AAV2, 3, 5 are human viruses

Acknowledgements

• Virus Discovery Group• Jun Lu• Ian Mills• Tri Nguyen • Susan Wong• Ning Zhi

• Hematology Branch• Neal Young• Sachiko Kajigaya

• Outside collaborations• Mavis Agbanje-McKenna• Sally Baylis• Eric Delwart• Erik Heegaard• Mei-Ying Yu

• Health Protection Agency• Hazel Appleton

D e n so v irus

Ite ra v irus

B re v id e n so v irus

P e fun d en sov irus

D e n sov irin ae(S u b fa m ily)

M V M

C a n ine p a rvo v irusC P V

P o rc ine p a rvo v irusP P V

Parvovirus

A A V s-1 -?

G o ose pa rvov irusG P V

A v ia n A A VA A A V

Dependovirus

P a rvov irus B 19B 1 9V

S im ian p a rvo v irusS P V

P m P V

Erythrovirus

B o v in e pa rvov irusB P V

M inute v iru s of canine sM V C

H u m an b o ca v irus

Bocavirus

A le u tio n d ise a se(m in ks )

P a rv4 /P a rv5

Amdovirus

Parvovirinae(S u b fa m ily)

Parvoviridae(F a m ily )