Parvovirus B19 Achievements and Challenges

Parvovirus B19 is a widespread human pathogenic virus, member of theErythrovirusgenus in the Parvoviridae family. Infection can be associated with an ample range of pathologies and clinical manifestations, whose characteristics and outcomes depend on the interplay between the pathogenetic potential of the virus, its adaptation to different cellular environments, and the physiological and immune status of the infected individuals. The scope of this review is the advances in knowledge on the biological characteristics of the virus and of virus-host relationships; in particular, the interactions of the virus with different cellular environments in terms of tropism and ability to achieve a productive replicative cycle, or, on the contrary, to establish persistence; the consequences of infection in terms of interference with the cell physiology; the process of recognition of the virus by the innate or adaptive immune system, hence the role of the immune system in controlling the infection or in the development of clinical manifestations. Linked to these issues is the continuous effort to develop better diagnostic algorithms and methods and the need for development of prophylactic and therapeutic options for B19V infections

Parvovirus B19: recent insights and implications for pathogenesis, diagnosis and therapy

Parvovirus B19 is a human pathogenic virus, a ssDNA member of the family Parvoviridae, characterized by a selective tropism for erythroid progenitor cells (EPCs) in the bone marrow and an ample pathogenetic potential. The selective tropism for EPCs can be explained both in terms of receptor-mediated tropism and of an intracellular permissive environment conditioned by the cell differentiation and proliferation stage. Infection of EPCs is productive, induces apoptosis and leads to a temporary arrest of erythropoiesis, which can usually be manifest in cases of underlying erythropoietic disorders or immune system deficiencies. Endothelial cells constitute an additional diffuse target, whose infection is mediated by ADE phenomenon, but is normally nonproductive and mainly leading to inflammatory processes. The relevance of parvovirus as a cardiotropic virus is recently emerging, while its capability of intrauterine transmission and consequences on the fetus is known and should not be overlooked. To the purpose of diagnosis, a combination of molecular and immunological methods offers the best discrimination of active infectious processes, and an application of these methods especially in cases of atypical presentations should be encouraged. Ongoing research is directed towards the development of a vaccine and the discovery of antiviral drugs that may be useful in the prevention and treatment of parvovirus B19 infections

Parvovirus B19 DNA CpG Dinucleotide Methylation and Epigenetic Regulation of Viral Expression

CpG DNA methylation is one of the main epigenetic modifications playing a role in the control of gene expression. For DNA viruses whose genome has the ability to integrate in the host genome or to maintain as a latent episome, a correlation has been found between the extent of DNA methylation and viral quiescence. No information is available for Parvovirus B19, a human pathogenic virus, which is capable of both lytic and persistent infections. Within Parvovirus B19 genome, the inverted terminal regions display all the characteristic signatures of a genomic CpG island; therefore we hypothesised a role of CpG dinucleotide methylation in the regulation of viral genome expression

Molecular Testing for Parvoviruses

The family Parvoviridae includes viruses with a single-stranded DNA genome, encapsidated in an icosahedral protein capsid, about 2226 nm in diameter. Replication occurs in the nucleus of infected cells and is highly dependent on cellular environment, so that a productive cycle is usually achieved only in actively replicating cells, or in some cases when supported by complementation from helper viruses. The subfamily Parvovirinae includes viruses able to infect vertebrate hosts, within it the most recent taxonomical revision distinguishes eight viral genera, and within each genus individual virus species that collect the viral isolates normally recognized in laboratory or clinical settings

New Insights into Parvovirus Research

Viruses in the Parvoviridae family constitute one of the most diverse and intriguing fields of research. While they all share an ssDNA genome and a small capsid, they can differ widely in structure, genome organization and expression, virus–cell interaction, and impact on the host. Exploring such diversity and unraveling the inherent complexity in these apparently simple viruses is an ongoing endeavor and commitment for the scientific community. The translational implications of research on parvoviruses are relevant. Within the family, some viruses are important human and veterinary pathogens, in need of diagnostic methods and antiviral strategies; other viruses have long been studied and engineered as tools for oncolytic therapy, or as sophisticated gene delivery vectors, and can now display their wide and expanding applicative potential. This Special Issue of Viruses collects recent contributions in the field of parvovirus research, with a focus on new insights and research on unresolved issues, as well as new approaches exploiting systemic methodologies. Evolution, structural biology, viral replication, virus–host interaction, pathogenesis and immunity, and viral oncotherapy are a selection of the topics addressed in the issue that can be of relevance to the community involved in parvovirus research and of interest to a wider audience

Parvovirus B19: recent insights and implications for pathogenesis, diagnosis and therapy

Parvovirus B19 is a human pathogenic virus, a ssDNA member of the family Parvoviridae, characterized by a selective tropism for erythroid progenitor cells (EPCs) in the bone marrow and an ample pathogenetic potential. The selective tropism for EPCs can be explained both in terms of receptor-mediated tropism and of an intracellular permissive environment conditioned by the cell differentiation and proliferation stage. Infection of EPCs is productive, induces apoptosis and leads to a temporary arrest of erythropoiesis, which can usually be manifest in cases of underlying erythropoietic disorders or immune system deficiencies. Endothelial cells constitute an additional diffuse target, whose infection is mediated by ADE phenomenon, but is normally nonproductive and mainly leading to inflammatory processes. The relevance of parvovirus as a cardiotropic virus is recently emerging, while its capability of intrauterine transmission and consequences on the fetus is known and should not be overlooked. To the purpose of diagnosis, a combination of molecular and immunological methods offers the best discrimination of active infectious processes, and an application of these methods especially in cases of atypical presentations should be encouraged. Ongoing research is directed towards the development of a vaccine and the discovery of antiviral drugs that may be useful in the prevention and treatment of parvovirus B19 infections

Parvovirus B19 Achievements and Challenges

Parvovirus B19 is a widespread human pathogenic virus, member of the Erythrovirus genus in the Parvoviridae family. Infection can be associated with an ample range of pathologies and clinical manifestations, whose characteristics and outcomes depend on the interplay between the pathogenetic potential of the virus, its adaptation to different cellular environments, and the physiological and immune status of the infected individuals. The scope of this review is the advances in knowledge on the biological characteristics of the virus and of virus-host relationships; in particular, the interactions of the virus with different cellular environments in terms of tropism and ability to achieve a productive replicative cycle, or, on the contrary, to establish persistence; the consequences of infection in terms of interference with the cell physiology; the process of recognition of the virus by the innate or adaptive immune system, hence the role of the immune system in controlling the infection or in the development of clinical manifestations. Linked to these issues is the continuous effort to develop better diagnostic algorithms and methods and the need for development of prophylactic and therapeutic options for B19V infections