scholarly journals RNA Binding Motif Protein RBM45 Regulates Expression of the 11-Kilodalton Protein of Parvovirus B19 through Binding to Novel Intron Splicing Enhancers

mBio ◽  
2020 ◽  
Vol 11 (2) ◽  
Author(s):  
Jianke Wang ◽  
Safder S. Ganaie ◽  
Fang Cheng ◽  
Peng Xu ◽  
Kang Ning ◽  
...  
Keyword(s):  
Rna Binding ◽  
Nonstructural Protein ◽  
Parvovirus B19 ◽  
Binding Motif ◽  
Erythroid Progenitor ◽  
Hematological Disorders ◽  
Erythroid Progenitor Cells ◽  
Alternatively Spliced ◽  
Precursor Mrna ◽  
Single Promoter

ABSTRACT During infection of human parvovirus B19 (B19V), one viral precursor mRNA (pre-mRNA) is transcribed by a single promoter and is alternatively spliced and alternatively polyadenylated. Here, we identified a novel cis-acting sequence (5′-GUA AAG CUA CGG GAC GGU-3′), intronic splicing enhancer 3 (ISE3), which lies 72 nucleotides upstream of the second splice acceptor (A2-2) site of the second intron that defines the exon of the mRNA encoding the 11-kDa viral nonstructural protein. RNA binding motif protein 45 (RBM45) specifically binds to ISE3 with high affinity (equilibrium dissociation constant [KD] = 33 nM) mediated by its RNA recognition domain and 2-homo-oligomer assembly domain (RRM2-HOA). Knockdown of RBM45 expression or ectopic overexpression of RRM2-HOA in human erythroid progenitor cells (EPCs) expanded ex vivo significantly decreased the level of viral mRNA spliced at the A2-2 acceptor but not that of the mRNA spliced at A2-1 that encodes VP2. Moreover, silent mutations of ISE3 in an infectious DNA of B19V significantly reduced 11-kDa expression. Notably, RBM45 also specifically interacts in vitro with ISE2, which shares the octanucleotide (GGGACGGU) with ISE3. Taken together, our results suggest that RBM45, through binding to both ISE2 and ISE3, is an essential host factor for maturation of 11-kDa-encoding mRNA. IMPORTANCE Human parvovirus B19 (B19V) is a human pathogen that causes severe hematological disorders in immunocompromised individuals. B19V infection has a remarkable tropism with respect to human erythroid progenitor cells (EPCs) in human bone marrow and fetal liver. During B19V infection, only one viral precursor mRNA (pre-mRNA) is transcribed by a single promoter of the viral genome and is alternatively spliced and alternatively polyadenylated, a process which plays a key role in expression of viral proteins. Our studies revealed that a cellular RNA binding protein, RBM45, binds to two intron splicing enhancers and is essential for the maturation of the small nonstructural protein 11-kDa-encoding mRNA. The 11-kDa protein plays an important role not only in B19V infection-induced apoptosis but also in viral DNA replication. Thus, the identification of the RBM45 protein and its cognate binding site in B19V pre-mRNA provides a novel target for antiviral development to combat B19V infection-caused severe hematological disorders.

scholarly journals New Insights of Human Parvovirus B19 in Modulating Erythroid Progenitor Cells Differentiation

2019 ◽  
Author(s):  
Shuwen Feng ◽  
Dongxin Zeng ◽  
Junwen Zheng ◽  
Dongchi Zhao
Keyword(s):  
Progenitor Cells ◽  
Nonstructural Protein ◽  
Parvovirus B19 ◽  
Fetal Loss ◽  
Main Body ◽  
Severe Anemia ◽  
Red Cell ◽  
Human Parvovirus B19 ◽  
Erythroid Progenitor ◽  
Erythroid Progenitor Cells

Background Human parvovirus B19, a human pathogen of the erythroparvovirus genus, is responsible for a variety of diseases. Despite less symptoms caused by B19 infection in healthy individuals, this pathogen can not be neglected in specific groups who exhibit severe anemia. Main body of abstract Transient aplastic crisis and pure red cell aplasia are two kinds of anemic hemogram respectively in acute phase and chronic B19 infection, especially occur in individuals with a shortened red cell survival or immunocompromised patients. In addition, B19 infected pregnant women may suffer risks of hydrops fetalis secondary to severe anemia and fetal loss. B19 possesses high affinity to bone marrow and fetal liver due to its extremely restricted cytotoxicity to erythroid progenitor cells mediated by viral proteins. The nonstructural protein NS1 is considered to be the major pathogenic factor, which takes parts in differentiational inhibition and apoptosis of erythroid progenitor cells through inducing viral DNA damage responses and cell cycle arrest. The time phase property of NS1 activity during DNA replication and conformity to transient change of hemogram are suggestive of its role in regulating differentiation of hematopoietic cells, which is not completely understood. Conclusion In this review, we set up a hypothetic bridge between B19 NS1 and Notch signaling pathway or transcriptional factors GATA which are essential in hematopoiesis, to provide a new insight of the potential mechanism of B19-induced differentiational inhibition of erythroid progenitor cells.

scholarly journals 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

Blood ◽  
2010 ◽  
Vol 115 (5) ◽  
pp. 1070-1080 ◽  
Author(s):  
Aaron Yun Chen ◽  
Elizabeth Yan Zhang ◽  
Wuxiang Guan ◽  
Fang Cheng ◽  
Steve Kleiboeker ◽  
...  
Keyword(s):  
Progenitor Cells ◽  
Ex Vivo ◽  
Nonstructural Protein ◽  
Parvovirus B19 ◽  
Death Receptor ◽  
Human Parvovirus B19 ◽  
Nonstructural Proteins ◽  
Erythroid Progenitors ◽  
Erythroid Progenitor ◽  
Erythroid Progenitor Cells

AbstractHuman parvovirus B19 (B19V) infection shows a strong erythroid tropism and drastically destroys erythroid progenitor cells, thus leading to most of the disease outcomes associated with B19V infection. In this study, we systematically examined the 3 B19V nonstructural proteins, 7.5kDa, 11kDa, and NS1, for their function in inducing apoptosis in transfection of primary ex vivo–expanded erythroid progenitor cells, in comparison with apoptosis induced during B19V infection. Our results show that 11kDa is a more significant inducer of apoptosis than NS1, whereas 7.5kDa does not induce apoptosis. Furthermore, we determined that caspase-10, an initiator caspase in death receptor signaling, is the most active caspase in apoptotic erythroid progenitors induced by 11kDa and NS1 as well as during B19V infection. More importantly, cytoplasm-localized 11kDa is expressed at least 100 times more than nucleus-localized NS1 at the protein level in primary erythroid progenitor cells infected with B19V; and inhibition of 11kDa expression using antisense oligos targeting specifically to the 11kDa-encoding mRNAs reduces apoptosis significantly during B19V infection of erythroid progenitor cells. Taken together, these results demonstrate that the 11kDa protein contributes to erythroid progenitor cell death during B19V infection.

scholarly journals Ex Vivo-Generated CD36+ Erythroid Progenitors Are Highly Permissive to Human Parvovirus B19 Replication

2007 ◽  
Vol 82 (5) ◽  
pp. 2470-2476 ◽  
Author(s):  
Susan Wong ◽  
Ning Zhi ◽  
Claudia Filippone ◽  
Keyvan Keyvanfar ◽  
Sachiko Kajigaya ◽  
...  
Keyword(s):  
Progenitor Cells ◽  
Real Time ◽  
Cell Lines ◽  
Ex Vivo ◽  
Parvovirus B19 ◽  
Erythroid Progenitor ◽  
Hematopoietic Stem ◽  
Human Virus ◽  
Erythroid Progenitor Cells ◽  
Large Numbers

ABSTRACT The pathogenic parvovirus B19 (B19V) has an extreme tropism for human erythroid progenitor cells. In vitro, only a few erythroid leukemic cell lines (JK-1 and KU812Ep6) or megakaryoblastoid cell lines (UT7/Epo and UT7/Epo-S1) with erythroid characteristics support B19V replication, but these cells are only semipermissive. By using recent advances in generating large numbers of human erythroid progenitor cells (EPCs) ex vivo from hematopoietic stem cells (HSCs), we produced a pure population of CD36+ EPCs expanded and differentiated from CD34+ HSCs and assessed the CD36+ EPCs for their permissiveness to B19V infection. Over more than 3 weeks, cells grown in serum-free medium expanded more than 800,000-fold, and 87 to 96% of the CD36+ EPCs were positive for globoside, the cellular receptor for B19V. Immunofluorescence (IF) staining showed that about 77% of the CD36+ EPCs were positive for B19V infection, while about 9% of UT7/Epo-S1 cells were B19V positive. Viral DNA detected by real-time PCR increased by more than 3 logs in CD36+ EPCs; the increase was 1 log in UT7/Epo-S1 cells. Due to the extensive permissivity of CD36+ EPCs, we significantly improved the sensitivity of detection of infectious B19V by real-time reverse transcription-PCR and IF staining 100- and 1,000-fold, respectively, which is greater than the sensitivity of UT7/Epo-S1 cell-based methods. This is the first description of an ex vivo method to produce large numbers of EPCs that are highly permissive to B19V infection and replication, offering a cellular system that mimics in vivo infection with this pathogenic human virus.

scholarly journals Antibody-Mediated Enhancement of Parvovirus B19 Uptake into Endothelial Cells Mediated by a Receptor for Complement Factor C1q

2014 ◽  
Vol 88 (14) ◽  
pp. 8102-8115 ◽  
Author(s):  
Kristina von Kietzell ◽  
Tanja Pozzuto ◽  
Regine Heilbronn ◽  
Tobias Grössl ◽  
Henry Fechner ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Progenitor Cells ◽  
Parvovirus B19 ◽  
Cell Types ◽  
Complement Factor ◽  
Human Parvovirus B19 ◽  
Erythroid Progenitor ◽  
Antibody Dependent Enhancement ◽  
Erythroid Progenitor Cells ◽  
Additional Cell

ABSTRACTDespite its strong host tropism for erythroid progenitor cells, human parvovirus B19 (B19V) can also infect a variety of additional cell types. Acute and chronic inflammatory cardiomyopathies have been associated with a high prevalence of B19V DNA in endothelial cells of the myocardium. To elucidate the mechanisms of B19V uptake into endothelium, we first analyzed the surface expression of the well-characterized primary B19V receptor P antigen and the putative coreceptors α5β1integrins and Ku80 antigen on primary and permanent endothelial cells. The receptor expression pattern and also the primary attachment levels were similar to those in the UT7/Epo-S1 cell line regarded as functional for B19V entry, but internalization of the virus was strongly reduced. As an alternative B19V uptake mechanism in endothelial cells, we demonstrated antibody-dependent enhancement (ADE), with up to a 4,000-fold increase in B19V uptake in the presence of B19V-specific human antibodies. ADE was mediated almost exclusively at the level of virus internalization, with efficient B19V translocation to the nucleus. In contrast to monocytes, where ADE of B19V has been described previously, enhancement does not rely on interaction of the virus-antibody complexes with Fc receptors (FcRs), but rather, involves an alternative mechanism mediated by the heat-sensitive complement factor C1q and its receptor, CD93. Our results suggest that ADE represents the predominant mechanism of endothelial B19V infection, and it is tempting to speculate that it may play a role in the pathogenicity of cardiac B19V infection.IMPORTANCEBoth efficient entry and productive infection of human parvovirus B19 (B19V) seem to be limited to erythroid progenitor cells. However,in vivo, the viral DNA can also be detected in additional cell types, such as endothelial cells of the myocardium, where its presence has been associated with acute and chronic inflammatory cardiomyopathies. In this study, we demonstrated that uptake of B19V into endothelial cells most probably does not rely on the classical receptor-mediated route via the primary B19V receptor P antigen and coreceptors, such as α5β1integrins, but rather on antibody-dependent mechanisms. Since the strong antibody-dependent enhancement (ADE) of B19V entry requires the CD93 surface protein, it very likely involves bridging of the B19V-antibody complexes to this receptor by the complement factor C1q, leading to enhanced endocytosis of the virus.

scholarly journals Enhanced Cell-Based Detection of Parvovirus B19V Infectious Units According to Cell Cycle Status

Viruses ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 1467
Author(s):  
Céline Ducloux ◽  
Bruno You ◽  
Amandine Langelé ◽  
Olivier Goupille ◽  
Emmanuel Payen ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Line ◽  
Parvovirus B19 ◽  
Health State ◽  
Fetal Hydrops ◽  
M Cell ◽  
Viral Inactivation ◽  
Erythroid Progenitor ◽  
Erythroid Progenitor Cells ◽  
Cell Cycle Status

Human parvovirus B19 (B19V) causes various human diseases, ranging from childhood benign infection to arthropathies, severe anemia and fetal hydrops, depending on the health state and hematological status of the patient. To counteract B19V blood-borne contamination, evaluation of B19 DNA in plasma pools and viral inactivation/removal steps are performed, but nucleic acid testing does not correctly reflect B19V infectivity. There is currently no appropriate cellular model for detection of infectious units of B19V. We describe here an improved cell-based method for detecting B19V infectious units by evaluating its host transcription. We evaluated the ability of various cell lines to support B19V infection. Of all tested, UT7/Epo cell line, UT7/Epo-STI, showed the greatest sensitivity to B19 infection combined with ease of performance. We generated stable clones by limiting dilution on the UT7/Epo-STI cell line with graduated permissiveness for B19V and demonstrated a direct correlation between infectivity and S/G2/M cell cycle stage. Two of the clones tested, B12 and E2, reached sensitivity levels higher than those of UT7/Epo-S1 and CD36+ erythroid progenitor cells. These findings highlight the importance of cell cycle status for sensitivity to B19V, and we propose a promising new straightforward cell-based method for quantifying B19V infectious units.

scholarly journals The Genome of Human Parvovirus B19 Can Replicate in Nonpermissive Cells with the Help of Adenovirus Genes and Produces Infectious Virus

2009 ◽  
Vol 83 (18) ◽  
pp. 9541-9553 ◽  
Author(s):  
Wuxiang Guan ◽  
Susan Wong ◽  
Ning Zhi ◽  
Jianming Qiu
Keyword(s):  
Nonstructural Protein ◽  
Parvovirus B19 ◽  
Leukemic Cell ◽  
Progeny Virus ◽  
Human Parvovirus B19 ◽  
Erythroid Progenitor ◽  
Leukemic Cell Lines ◽  
Nonstructural Protein 1 ◽  
293 Cells

ABSTRACT Human parvovirus B19 (B19V) is a member of the genus Erythrovirus in the family Parvoviridae. In vitro, autonomous B19V replication is limited to human erythroid progenitor cells and in a small number of erythropoietin-dependent human megakaryoblastoid and erythroid leukemic cell lines. Here we report that the failure of B19V DNA replication in nonpermissive 293 cells can be overcome by adenovirus infection. More specifically, the replication of B19V DNA in the 293 cells and the production of infectious progeny virus were made possible by the presence of the adenovirus E2a, E4orf6, and VA RNA genes that emerged during the transfection of the pHelper plasmid. Using this replication system, we identified the terminal resolution site and the nonstructural protein 1 (NS1) binding site on the right terminal palindrome of the viral genome, which is composed of a minimal origin of replication spanning 67 nucleotides. Plasmids or DNA fragments containing an NS1 expression cassette and this minimal origin were able to replicate in both pHelper-transfected 293 cells and B19V-semipermissive UT7/Epo-S1 cells. Our results have important implications for our understanding of native B19V infection.

scholarly journals Human Parvovirus B19

2002 ◽  
Vol 15 (3) ◽  
pp. 485-505 ◽  
Author(s):  
Erik D. Heegaard ◽  
Kevin E. Brown
Keyword(s):  
Parvovirus B19 ◽  
Blot Hybridization ◽  
Immunocompromised Host ◽  
Pure Red Cell Aplasia ◽  
Enzyme Linked Immunosorbent Assay ◽  
Dot Blot ◽  
Erythema Infectiosum ◽  
Erythroid Progenitor ◽  
Erythroid Progenitor Cells ◽  
Transient Aplastic Crisis

SUMMARY Parvovirus B19 (B19) was discovered in 1974 and is the only member of the family Parvoviridae known to be pathogenic in humans. Despite the inability to propagate the virus in cell cultures, much has been learned about the pathophysiology of this virus, including the identification of the cellular receptor (P antigen), and the control of the virus by the immune system. B19 is widespread, and manifestations of infection vary with the immunologic and hematologic status of the host. In healthy immunocompetent individuals B19 is the cause of erythema infectiosum and, particularly in adults, acute symmetric polyarthropathy. Due to the tropism of B19 to erythroid progenitor cells, infection in individuals with an underlying hemolytic disorder causes transient aplastic crisis. In the immunocompromised host persistent B19 infection is manifested as pure red cell aplasia and chronic anemia. Likewise, the immature immune response of the fetus may render it susceptible to infection, leading to fetal death in utero, hydrops fetalis, or development of congenital anemia. B19 has also been suggested as the causative agent in a variety of clinical syndromes, but given the common nature, causality is often difficult to infer. Diagnosis is primarily based on detection of specific antibodies by enzyme-linked immunosorbent assay or detection of viral DNA by dot blot hybridization or PCR. Treatment of persistent infection with immunoglobulin reduces the viral load and results in a marked resolution of anemia. Vaccine phase I trials show promising results.

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