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 )