H5N1 clade 2.3.4.4b dynamics in experimentally infected calves and cows.

In March 2024, highly pathogenic avian influenza virus (HPAIV) clade 2.3.4.

Inhibition of sterol O-acyltransferase 1 blocks Zika virus infection in cell lines and cerebral organoids.

Viruses depend on host metabolic pathways and flaviviruses are specifically linked to lipid metabolism. During dengue virus infection lipid droplets are degraded to fuel replication and Zika virus (ZIKV) infection depends on triglyceride biosynthesis. Here, we systematically investigated the neutral lipid-synthesizing enzymes diacylglycerol O-acyltransferases (DGAT) and the sterol O-acyltransferase (SOAT) 1 in orthoflavivirus infection.

Outcome of H5N1 clade 2.3.4.4b virus infection in calves and lactating cows.

In March 2024, highly pathogenic avian influenza virus (HPAIV) clade 2.3.4.

3D Spheroid and Organoid Models to Study Neuroinfection of RNA Viruses.

Three-dimensional culture models of the brain enable the study of neuroinfection in the context of a complex interconnected cell matrix. Depending on the differentiation status of the neural cells, two models exist: 3D spheroids also called neurospheres and cerebral organoids. Here, we describe the preparation of 3D spheroids and cerebral organoids and give an outlook on their usage to study Rift Valley fever virus and other neurotropic viruses.

CYP19A1 mediates severe SARS-CoV-2 disease outcome in males.

Male sex represents one of the major risk factors for severe COVID-19 outcome. However, underlying mechanisms that mediate sex-dependent disease outcome are as yet unknown. Here, we identify the CYP19A1 gene encoding for the testosterone-to-estradiol metabolizing enzyme CYP19A1 (also known as aromatase) as a host factor that contributes to worsened disease outcome in SARS-CoV-2-infected males.

The proprotein convertase SKI-1/S1P is a critical host factor for Nairobi sheep disease virus infectivity.

Nairobi sheep disease virus (NSDV) belongs to the Orthonairovirus genus in the Bunyavirales order and is genetically related to human-pathogenic Crimean-Congo hemorrhagic fever virus (CCHFV). NSDV is a zoonotic pathogen transmitted by ticks and primarily affects naïve small ruminants in which infection leads to severe and often fatal hemorrhagic gastroenteritis. Despite its veterinary importance and the striking similarities in the clinical picture between NSDV-infected ruminants and CCHFV patients, the molecular pathogenesis of NSDV and its interactions with the host cell are largely unknown.

αVβ3 Integrin Expression Is Essential for Replication of Mosquito and Tick-Borne Flaviviruses in Murine Fibroblast Cells.

The genus includes a number of important viruses that are pathogenic to humans and animals and are responsible for outbreaks across the globe. Integrins, a family of heterodimeric transmembrane molecules expressed in all nucleated cells mediate critical functions of cell physiology and cell cycle. Integrins were previously postulated to be involved in flavivirus entry and to modulate flavivirus replication efficiency.

Offspring born to influenza A virus infected pregnant mice have increased susceptibility to viral and bacterial infections in early life.

Influenza during pregnancy can affect the health of offspring in later life, among which neurocognitive disorders are among the best described. Here, we investigate whether maternal influenza infection has adverse effects on immune responses in offspring. We establish a two-hit mouse model to study the effect of maternal influenza A virus infection (first hit) on vulnerability of offspring to heterologous infections (second hit) in later life.

ANP32B Deficiency Protects Mice From Lethal Influenza A Virus Challenge by Dampening the Host Immune Response.

Deciphering complex virus-host interactions is crucial for pandemic preparedness. In this study, we assessed the impact of recently postulated cellular factors ANP32A and ANP32B of influenza A virus (IAV) species specificity on viral pathogenesis in a genetically modified mouse model. Infection of ANP32A and ANP32A mice with a seasonal H3N2 IAV or a highly pathogenic H5N1 human isolate did not result in any significant differences in virus tropism, innate immune response or disease outcome.

Indirect ELISA based on Hendra and Nipah virus proteins for the detection of henipavirus specific antibodies in pigs.

Hendra virus (HeV) and Nipah virus (NiV) belong to the genus Henipavirus in the family Paramyxoviridae. Henipavirus infections were first reported in the 1990's causing severe and often fatal outbreaks in domestic animals and humans in Southeast Asia and Australia. NiV infections were observed in humans in Bangladesh, India and in the first outbreak in Malaysia, where pigs were also infected.

Bat Astroviruses: Towards Understanding the Transmission Dynamics of a Neglected Virus Family.

Bats belong to the order Chiroptera that represents the second largest order of mammals with more than 1200 species and an almost global distribution. Environmental changes and deforestation have severely influenced many ecosystems, intensifying the contact between wildlife and humans. In recent years, bats have been found to harbor a number of different viruses with zoonotic potential, as well as a great diversity of astroviruses, for which the question of zoonotic potential remains unanswered to date.

Expression, characterisation and antigenicity of a truncated Hendra virus attachment protein expressed in the protozoan host Leishmania tarentolae.

Hendra virus (HeV) is an emerging zoonotic paramyxovirus within the genus Henipavirus that has caused severe morbidity and mortality in humans and horses in Australia since 1994. HeV infection of host cells is mediated by the membrane bound attachment (G) and fusion (F) glycoproteins, that are essential for receptor binding and fusion of viral and cellular membranes. The eukaryotic unicellular parasite Leishmania tarentolae has recently been established as a powerful tool to express recombinant proteins with mammalian-like glycosylation patterns, but only few viral proteins have been expressed in this system so far.

Serologic survey of West Nile virus in horses from Central-West, Northeast and Southeast Brazil.

Since the emergence of West Nile virus (WNV) in North America in 1999, there have been several reports of WNV activity in Central and South American countries. To detect WNV in Brazil, we performed a serological survey of horses from different regions of Brazil using recombinant peptides from domain III of WNV. Positive samples were validated with the neutralisation test.

Production and diagnostic application of recombinant domain III of West Nile envelope protein in Brazil.

Introduction: West Nile virus (WNV) is a flavivirus with a natural cycle involving mosquitoes and birds. Over the last 11 years, WNV has spread throughout the Americas with the imminent risk of its introduction in Brazil.

Methods: Envelope protein domain III of WNV (rDIII) was bacterially expressed and purified.