The small 11kDa nonstructural protein of human parvovirus B19 plays a key role in inducing apoptosis during B19 virus infection of primary erythroid progenitor cells

Chen, Aaron Yun; Zhang, Elizabeth Yan; Guan, Wuxiang; Cheng, Fang; Kleiboeker, Steve; Yankee, Thomas M.; Qiu, Jianming

doi:10.1182/blood-2009-04-215756

Cited by 75 publications

(82 citation statements)

References 46 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Similarly, the newly identified splice acceptor site at AAV2 nt 4138 may have counterparts in B19 (nt 4883) and SPV (nt 4638) at the right ends of the respective genomes. For parvovirus B19, a multiply spliced transcript involving the above-described splice sites is translated to a small protein of 11 kDa, which appears to increase viral infectivity in vivo (52) and may play a role in apoptosis and cell signaling pathways (53,54). In cell culture the novel 18-kDa Rep/VP protein only had a minor effect on AAV replication.…”

Section: Discussionmentioning

confidence: 99%

A Comprehensive RNA Sequencing Analysis of the Adeno-Associated Virus (AAV) Type 2 Transcriptome Reveals Novel AAV Transcripts, Splice Variants, and Derived Proteins

Stutika

Gogol-Döring

Botschen

et al. 2016

J Virol

View full text Add to dashboard Cite

Adeno-associated virus (AAV) is recognized for its bipartite life cycle with productive replication dependent on coinfection with adenovirus (Ad) and AAV latency being established in the absence of a helper virus. The shift from latent to Ad-dependent AAV replication is mostly regulated at the transcriptional level. The current AAV transcription map displays highly expressed transcripts as found upon coinfection with Ad. So far, AAV transcripts have only been characterized on the plus strand of the AAV single-stranded DNA genome. The AAV minus strand is assumed not to be transcribed. Here, we apply Illumina-based RNA sequencing (RNA-Seq) to characterize the entire AAV2 transcriptome in the absence or presence of Ad. We find known and identify novel AAV transcripts, including additional splice variants, the most abundant of which leads to expression of a novel 18-kDa Rep/VP fusion protein. Furthermore, we identify for the first time transcription on the AAV minus strand with clustered reads upstream of the p5 promoter, confirmed by 5' rapid amplification of cDNA ends and RNase protection assays. The p5 promoter displays considerable activity in both directions, a finding indicative of divergent transcription. Upon infection with AAV alone, low-level transcription of both AAV strands is detectable and is strongly stimulated upon coinfection with Ad. A deno-associated viruses (AAV) are helper-dependent members of the parvovirus group that require coinfection with an unrelated helper virus, particularly adenovirus (Ad) for productive replication (1). Despite of several identified AAV serotypes most research has been done with prototype AAV type 2. The AAV2 genome consists of a linear, single-stranded DNA of 4.7 kb. Both ends carry identical inverted terminal repeats (ITR) of 145 bp (2), which flank the two major open reading frames (ORF), called rep and cap. The rep ORF codes for four nonstructural proteins, Rep78 and a C-terminally spliced variant, Rep68. In addition, N-terminally truncated versions thereof are expressed, called Rep52 and Rep40, respectively. The Rep proteins are required as regulators for various steps of the AAV life cycle. AAV cap harbors the ORF for the capsid proteins (VP1 to -3) and a separate ORF for the assembly-activating protein (AAP) (3).The current knowledge of AAV transcription dates back to early research in the 1980s when the three AAV2 promoters, p5, p19, or p40 and major transcripts derived thereof were characterized (4, 5). All AAV transcripts identified since then map to only one DNA plus strand (6), which led to the assumption that the complementary AAV minus strand was not transcribed. Furthermore, spliced AAV transcripts were identified displaying a single, shared intron located in the center of the AAV2 genome (4, 7). Initially, a single splice donor site at AAV nucleotide 1906 and a single splice acceptor site located at nucleotide (nt) 2228 were described. Later, an alternative splice acceptor site at nt 2201 was detected (8), allowing the expression of VP1 protein ...

show abstract

Section: Discussionmentioning

confidence: 99%

A Comprehensive RNA Sequencing Analysis of the Adeno-Associated Virus (AAV) Type 2 Transcriptome Reveals Novel AAV Transcripts, Splice Variants, and Derived Proteins

Stutika

Gogol-Döring

Botschen

et al. 2016

J Virol

View full text Add to dashboard Cite

show abstract

“…Blocking the expression of the 11-kDa protein in recombinant virions significantly reduces viral infectivity; the expression of the small protein could be critical for VP2 protein expression and trafficking in infected cells (102). Chen and colleagues showed recently that the 11-kDa protein was highly expressed (at least 100 times more than NS1) in erythroid progenitors, mostly in the cytoplasm, and was a major inducer of apoptosis by the activation of caspase 10 (an initiator caspase recruited at the top of the caspase signaling cascade in the death receptor signaling pathway) (14). Moreover, B19V DNA could activate Toll-like receptor 9 into erythroid cells, leading to inhibition of cell growth (34).…”

Section: Virus Replication and Cell Apoptosismentioning

confidence: 99%

Advances in Human B19 Erythrovirus Biology

Servant‐Delmas

Lefrère

Morinet³

et al. 2010

J Virol

View full text Add to dashboard Cite

Since its discovery, human parvovirus B19 (B19V), now termed erythrovirus, has been associated with many clinical situations (neurological and myocardium infections, persistent B19V DNAemia) in addition to the prototype clinical manifestations, i.e., erythema infectiosum and erythroblastopenia crisis. In 2002, the use of new molecular tools led to the characterization of three different genotypes of human B19 erythrovirus. Although the genomic organization is conserved, the geographic distribution of the different genotypes varies worldwide, and the nucleotidic divergences can impact the molecular diagnosis of B19 virus infection. The cell cycle of the virus remains partially unresolved; however, recent studies have shed light on the mechanism of cell entry and the interactions of B19V proteins with apoptosis pathways.Before the recent descriptions of human bocavirus (2) and human parvovirus 4 (PARV4) (41), parvovirus B19 ([B19V] or erythrovirus B19) was the only known member of the Parvoviridae family to infect humans. The Erythrovirus genus contains B19V, erythroviruses that infect several simian species, and the parvovirus from Manchurian chipmunks (87a). These viruses share the remarkable property of replicating in and destroying erythroid progenitors. This strong in vitro tropism explains the difficulties in studying the replicative cycle of these viruses; indeed, the in vitro production and culture of erythroid progenitor cells remain delicate. An infectious B19V clone was described only recently (102), and its use, although mostly limited and allowing only a small amount of progeny production, led to constructions of recombinant viruses that were helpful in understanding the steps of the virus life cycle and the toxicity of the virus. Discovered in 1975 (19), B19V can cause a wide range of mild and self-limiting clinical manifestations, such as erythema infectiosum (fifth disease) and oligoarthritis (98). B19V infection can also cause acute anemia by aplastic crisis in patients whose red blood cells have shortened survival times (i.e., patients with sickle cell disease, thalassemia, spherocytosis, or any disorder of hemoglobin gene expression or red cell membrane constitution), chronic anemia in patients with congenital immunodeficiencies or human immunodeficiency virus (HIV) infection or who are undergoing chemotherapy for malignancies or organ transplants (48, 58), and hydrops fetalis or intrauterine death in infected fetuses (86). Recently, cases of neurological manifestations have been associated with B19V infection (22), as have myocardium infections (4,5,47,83), and the spectrum of B19V-linked diseases may further increase. CLINICAL MANIFESTATIONSThe primary route of transmission of B19V is the respiratory tract (via aerosol droplets), with a majority of infections occurring during childhood, but the infection may also be transmitted by organ transplantation and especially by transfusion of blood components, in particular by packed red cells from blood collected during the short preseroconversion vi...

show abstract

“…The 7.5-kDa and 11-kDa proteins encoded by abundant small mRNAs of B19V are unique among the parvoviruses characterized to date. Recently, Chen et al reported that the 11-kDa protein is a significant inducer of apoptosis in erythroid progenitors (14). NS1 is cytotoxic and plays a crucial role in B19V pathogenesis.…”

Section: Introductionmentioning

confidence: 99%

Human parvovirus B19 causes cell cycle arrest of human erythroid progenitors via deregulation of the E2F family of transcription factors

Wan¹,

Zhi²,

Wong³

et al. 2010

J. Clin. Invest.

View full text Add to dashboard Cite

Human parvovirus B19 (B19V) is the only human pathogenic parvovirus. It causes a wide spectrum of human diseases, including fifth disease (erythema infectiosum) in children and pure red cell aplasia in immunocompromised patients. B19V is highly erythrotropic and preferentially replicates in erythroid progenitor cells (EPCs). Current understanding of how B19V interacts with cellular factors to regulate disease progression is limited, due to a lack of permissive cell lines and animal models. Here, we employed a recently developed primary human CD36 + EPC culture system that is highly permissive for B19V infection to identify cellular factors that lead to cell cycle arrest after B19V infection. We found that B19V exploited the E2F family of transcription factors by downregulating activating E2Fs (E2F1 to E2F3a) and upregulating repressive E2Fs (E2F4 to E2F8) in the primary CD36 + EPCs. B19V nonstructural protein 1 (NS1) was a key viral factor responsible for altering E2F1-E2F5 expression, but not E2F6-E2F8 expression. Interaction between NS1 and E2F4 or E2F5 enhanced the nuclear import of these repressive E2Fs and induced stable G 2 arrest. NS1-induced G 2 arrest was independent of p53 activation and increased viral replication. Downstream E2F4/E2F5 targets, which are potentially involved in the progression from G 2 into M phase and erythroid differentiation, were identified by microarray analysis. These findings provide new insight into the molecular pathogenesis of B19V in highly permissive erythroid progenitors.

show abstract

The small 11kDa nonstructural protein of human parvovirus B19 plays a key role in inducing apoptosis during B19 virus infection of primary erythroid progenitor cells

Cited by 75 publications

References 46 publications

A Comprehensive RNA Sequencing Analysis of the Adeno-Associated Virus (AAV) Type 2 Transcriptome Reveals Novel AAV Transcripts, Splice Variants, and Derived Proteins

A Comprehensive RNA Sequencing Analysis of the Adeno-Associated Virus (AAV) Type 2 Transcriptome Reveals Novel AAV Transcripts, Splice Variants, and Derived Proteins

Advances in Human B19 Erythrovirus Biology

Human parvovirus B19 causes cell cycle arrest of human erythroid progenitors via deregulation of the E2F family of transcription factors

Contact Info

Product

Resources

About