DDO-adjuvanted influenza A virus nucleoprotein mRNA vaccine induces robust humoral and cellular type 1 immune responses and protects mice from challenge.

A challenge in viral vaccine development is to produce vaccines that generate both neutralizing antibodies to prevent infection and cytotoxic CD8 T-cells that target conserved viral proteins and can eliminate infected cells to control virus spread. mRNA technology offers an opportunity to design vaccines based on conserved CD8-targeting epitopes, but achieving robust antigen-specific CD8 T-cells remains a challenge. Here, we tested the viral-derived oligonucleotide DDO268 as an adjuvant in the context of a model influenza A virus (IAV) nucleoprotein (NP) mRNA vaccine in C57BL/6 mice.

Detection and characterization of Langya virus in , Republic of Korea.

This study reports the identification of Langya virus Korea (LayV KOR) during the surveillance of shrews in the Republic of Korea. LayV KOR represents the first identification of LayV outside of China, exhibiting approximately 80% and 95.5% homologies at nucleotide and amino acid levels.

DDO-adjuvanted influenza A virus nucleoprotein mRNA vaccine induces robust humoral and cellular type 1 immune responses and protects mice from challenge.

A challenge in viral vaccine development is to produce vaccines that generate both neutralizing antibodies to prevent infection and cytotoxic CD8 T-cells that target conserved viral proteins and can eliminate infected cells to control virus spread. mRNA vaccines offer an opportunity to design vaccines based on conserved CD8-targeting epitopes, but achieving robust antigen-specific CD8 T-cells remains a challenge. Here we tested the viral-derived oligonucleotide DDO268 as an adjuvant in the context of a model influenza A virus (IAV) nucleoprotein (NP) mRNA vaccine in C57BL/6 mice.

Molecular detection and genomic characterization of Samak Micromys paramyxovirus-1 and -2 in Micromys minutus, Republic of Korea.

Background: The discovery of viruses in small mammalian populations, particularly rodents, has expanded the family Paramyxoviridae. The overlap in habitats between rodents and humans increases the risk of zoonotic events, underscoring the importance of active surveillance. Rodent species, such as Apodemus agrarius, are natural hosts for Paramyxoviridae in the Republic of Korea (ROK).

Murine parainfluenza virus persists in lung innate immune cells sustaining chronic lung pathology.

Common respiratory viruses, including the human parainfluenza viruses, threaten human health seasonally and associate with the development of chronic lung diseases. Evidence suggests that these viruses can persist, but the sources of viral products in vivo and their impact on chronic respiratory diseases remain unknown. Using the murine parainfluenza virus Sendai, we demonstrate that viral protein and RNA persist in lung macrophages, type 2 innate lymphoid cells (ILC2s) and dendritic cells long after the infectious virus is cleared.

Identification of distinct genotypes in circulating RSV A strains based on variants in the virus replication-associated genes.

Respiratory syncytial virus (RSV) is a common cause of respiratory infection that often leads to hospitalization of infected younger children and older adults. RSV is classified into two strains, A and B, each with several subgroups or genotypes. One issue with the definition of these subgroups is the lack of a unified method of identification or genotyping.

Indiscriminate activities of different henipavirus polymerase complex proteins allow for efficient minigenome replication in hybrid systems.

The henipaviruses, including Nipah virus (NiV) and Hendra virus (HeV), are biosafety level 4 (BSL-4) zoonotic pathogens that cause severe neurological and respiratory disease in humans. To study the replication machinery of these viruses, we developed robust minigenome systems that can be safely used in BSL-2 conditions. The nucleocapsid (N), phosphoprotein (P), and large protein (L) of henipaviruses are critical elements of their replication machinery and thus essential support components of the minigenome systems.

Identification of distinct genotypes in circulating RSV A strains based on variants on the virus replication-associated genes.

Respiratory syncytial virus is a common cause of respiratory infection that often leads to hospitalization of infected younger children and older adults. RSV is classified into two strains, A and B, each with several subgroups or genotypes. One issue with the definition of these subgroups is the lack of a unified method of identification or genotyping.

Murine Parainfluenza Virus Persists in Lung Innate Immune Cells Sustaining Chronic Lung Pathology.

Respiratory viruses including the human parainfluenza viruses (hPIVs) are a constant burden to human health, with morbidity and mortality frequently increased after the acute phase of the infection. Although is proven that respiratory viruses can persist , the mechanisms of virus or viral products persistence, their sources, and their impact on chronic respiratory diseases are unknown. Here, we used Sendai virus (SeV) to model hPIV infection in mice and test whether virus persistence associates with the development of chronic lung disease.

Copy-back viral genomes induce a cellular stress response that interferes with viral protein expression without affecting antiviral immunity.

Antiviral responses are often accompanied by translation inhibition and formation of stress granules (SGs) in infected cells. However, the triggers for these processes and their role during infection remain subjects of active investigation. Copy-back viral genomes (cbVGs) are the primary inducers of the mitochondrial antiviral signaling (MAVS) pathway and antiviral immunity during Sendai virus (SeV) and respiratory syncytial virus (RSV) infections.

S RNA Intergenic Deletions Drive Viral Interference during Arenavirus Infections.

Arenaviruses, a family of negative-sense RNA viruses spread by rodents, are a leading cause of severe hemorrhagic fever in humans. Due to a paucity of antivirals and vaccines for arenaviruses, there is a need to identify new mechanisms for interfering with arenavirus replication. In several negative-sense RNA viruses, natural viral interference results from the production of non-standard viral genomes (nsVGs) that activate the innate immune system and/or compete for essential viral products.

VODKA2: a fast and accurate method to detect non-standard viral genomes from large RNA-seq data sets.

During viral replication, viruses carrying an RNA genome produce non-standard viral genomes (nsVGs), including copy-back viral genomes (cbVGs) and deletion viral genomes (delVGs), that play a crucial role in regulating viral replication and pathogenesis. Because of their critical roles in determining the outcome of RNA virus infections, the study of nsVGs has flourished in recent years, exposing a need for bioinformatic tools that can accurately identify them within next-generation sequencing data obtained from infected samples. Here, we present our data analysis pipeline, Viral Opensource DVG Key Algorithm 2 (VODKA2), that is optimized to run on a parallel computing environment for fast and accurate detection of nsVGs from large data sets.

Copy-back viral genomes induce a cellular stress response that interferes with viral protein expression without affecting antiviral immunity.

Antiviral responses are often accompanied by translation inhibition and formation of stress granules (SG) in infected cells. However, the triggers for these processes and their role during infection remain subjects of active investigation. Copy-back viral genomes (cbVGs) are the primary inducers of the Mitochondrial Antiviral Signaling (MAVS) pathway and antiviral immunity during Sendai Virus (SeV) and Respiratory Syncytial virus (RSV) infections.

VODKA2: A fast and accurate method to detect non-standard viral genomes from large RNA-seq datasets.

During viral replication, viruses carrying an RNA genome produce non-standard viral genomes (nsVGs), including copy-back viral genomes (cbVGs) and deletion viral genomes (delVGs), that play a crucial role in regulating viral replication and pathogenesis. Because of their critical roles in determining the outcome of RNA virus infections, the study of nsVGs has flourished in recent years exposing a need for bioinformatic tools that can accurately identify them within Next-Generation Sequencing data obtained from infected samples. Here, we present our data analysis pipeline, Viral Opensource DVG Key Algorithm2 (VODKA2), that is optimized to run on a High Performance Computing (HPC) environment for fast and accurate detection of nsVGs from large data sets.

Non-standard viral genome-derived RNA activates TLR3 and type I IFN signaling to induce cDC1-dependent CD8+ T-cell responses during vaccination in mice.

There is a critical need to develop vaccine adjuvants that induce robust immune responses able to protect against intracellular pathogens, including viruses. Previously, we described defective viral genome-derived oligonucleotides (DDOs) as novel adjuvants that strongly induce type 1 immune responses, including protective Th1 CD4+ T-cells and effector CD8+ T-cells in mice. Here, we unravel the early innate response required for this type 1 immunity induction.

Accumulation of copy-back viral genomes during respiratory syncytial virus infection is preceded by diversification of the copy-back viral genome population followed by selection.

RNA viruses generate nonstandard viral genomes during their replication, including viral genomes of the copy-back (cbVGs) type that cannot replicate in the absence of a standard virus. cbVGs play a crucial role in shaping virus infection outcomes due to their ability to interfere with virus replication and induce strong immune responses. However, despite their critical role during infection, the principles that drive the selection and evolution of cbVGs within a virus population are poorly understood.

Fibroblast growth factor-9 expression in airway epithelial cells amplifies the type I interferon response and alters influenza A virus pathogenesis.

Influenza A virus (IAV) preferentially infects conducting airway and alveolar epithelial cells in the lung. The outcome of these infections is impacted by the host response, including the production of various cytokines, chemokines, and growth factors. Fibroblast growth factor-9 (FGF9) is required for lung development, can display antiviral activity in vitro, and is upregulated in asymptomatic patients during early IAV infection.

A Virus Is a Community: Diversity within Negative-Sense RNA Virus Populations.

Negative-sense RNA virus populations are composed of diverse viral components that interact to form a community and shape the outcome of virus infections. At the genomic level, RNA virus populations consist not only of a homogeneous population of standard viral genomes but also of an extremely large number of genome variants, termed viral quasispecies, and nonstandard viral genomes, which include copy-back viral genomes, deletion viral genomes, mini viral RNAs, and hypermutated RNAs. At the particle level, RNA virus populations are composed of pleomorphic particles, particles missing or having additional genomes, and single particles or particle aggregates.

Harnessing defective viruses to fight infections.

One of the most pressing challenges in medicine is to develop fast and effective strategies to combat infections. Xiao et al. report proof-of-concept experiments for the use of defective viral genomes as broad-spectrum antivirals by harnessing their ability to stimulate the innate immune response.