Immune responses in multiple hosts to Nucleocapsid Protein (NP) of Crimean-Congo Hemorrhagic Fever Virus (CCHFV)

In 2019, the World Health Organization declared 3 billion to be at risk of developing Crimean Congo Hemorrhagic Fever (CCHF). The causative agent of this deadly infection is CCHFV. The data related to the biology and immunology of CCHFV are rather scarce. Due to its indispensable roles in the viral life cycle, NP becomes a logical target for detailed viral immunology studies. In this study, humoral immunity to NP was investigated in CCHF survivors, as well as in immunized mice and rabbits. Abundant antibody response against NP was demonstrated both during natural infection in humans and following experimental immunizations in mice and rabbits. Also, cellular immune responses to recombinant NP (rNP) was detected in multispecies. This study represents the most comprehensive investigation on NP as an inducer of both humoral and cellular immunity in multiple hosts and proves that rNP is an excellent candidate warranting further immunological studies specifically on vaccine investigations.

High-throughput super-resolution analysis of influenza virus pleomorphism reveals insights into viral spatial organization

Many viruses form highly pleomorphic particles; in influenza, these particles range from spheres of ~ 100 nm in diameter to filaments of several microns in length. Virion structure is of interest, not only in the context of virus assembly, but also because pleomorphic variations may correlate with infectivity and pathogenicity. Detailed images of virus morphology often rely on electron microscopy, which is generally low throughput and limited in molecular identification. We have used fluorescence super-resolution microscopy combined with a rapid automated analysis pipeline to image many thousands of individual influenza virions, gaining information on their size, morphology and the distribution of membrane-embedded and internal proteins. This large-scale analysis revealed that influenza particles can be reliably characterised by length, that no spatial frequency patterning of the surface glycoproteins occurs, and that RNPs are preferentially located towards filament ends within Archetti bodies. Our analysis pipeline is versatile and can be adapted for use on multiple other pathogens, as demonstrated by its application for the size analysis of SARS-CoV-2. The ability to gain nanoscale structural information from many thousands of viruses in just a single experiment is valuable for the study of virus assembly mechanisms, host cell interactions and viral immunology, and should be able to contribute to the development of viral vaccines, anti-viral strategies and diagnostics.

Overcoming Immunological Challenges Limiting Capsid-Mediated Gene Therapy With Machine Learning

A key hurdle to making adeno-associated virus (AAV) capsid mediated gene therapy broadly beneficial to all patients is overcoming pre-existing and therapy-induced immune responses to these vectors. Recent advances in high-throughput DNA synthesis, multiplexing and sequencing technologies have accelerated engineering of improved capsid properties such as production yield, packaging efficiency, biodistribution and transduction efficiency. Here we outline how machine learning, advances in viral immunology, and high-throughput measurements can enable engineering of a new generation of de-immunized capsids beyond the antigenic landscape of natural AAVs, towards expanding the therapeutic reach of gene therapy.

Protective Effect of Arbidol Against Pulmonary Fibrosis and Sepsis in Mice

From the perspective of epidemiology, viral immunology and current clinical research, pulmonary fibrosis may become one of the complications of patients with Coronavirus Disease 2019 (COVID-19). Cytokine storm is a major cause of new coronavirus death. The purpose of this study was to explore the effects of antiviral drug arbidol on cytokine storm and pulmonary fibrosis. Here, we use a mouse model of bleomycin-induced pulmonary fibrosis and a mouse model of fecal dilution-induced sepsis to evaluate the effects of arbidol on pulmonary fibrosis and cytokine storm. The results showed that arbidol significantly reduced the area of pulmonary fibrosis and improved lung function (reduced inspiratory resistance, lung dynamic compliance and forced vital capacity increased). Treatment with arbidol promoted reduced sepsis severity 48 h after sepsis induction, based on weight, murine sepsis score and survival rate. Arbidol observably alleviates inflammatory infiltrates and injury in the lungs and liver. Finally, we also found that arbidol reduced serum levels of pro-inflammatory factors such as TNF-α and IL-6 induced by fecal dilution. In conclusion, our results indicate that arbidol can alleviate the severity of pulmonary fibrosis and sepsis, and provide some reference for the treatment of cytokine storm and sequelae of pulmonary fibrosis in patients with COVID-19.