Biology subjects

Salata, C.

Publications and source records attributed to Salata, C..

5 recordsLinked to original sources

bioRxiv2026

First detection and characterization of Alongshan virus in Ixodes ricinus ticks from Italy, 2021-2022

Alongshan virus (ALSV) is an emerging tick-borne segmented RNA virus belonging to the Jingmenvirus group and has been reported in humans, ticks, and vertebrates across Asia and Europe. Despite its potential public health relevance, its distribution and genetic diversity remain poorly characterized in several European regions where tick-borne pathogens are endemic. In this study, we developed a specific TaqMan-based real-time RT-PCR assay targeting a conserved region of ALSV segment 2 and used it to investigate the presence of ALSV RNA in Ixodes ricinus ticks collected in northeastern Italy. The assay showed high linearity over a broad dynamic range and no cross-reactivity with related flaviviruses. A total of 212 archival tick samples collected between March 2021 and November 2022 were screened, and 28 samples (13.2%) tested positive for ALSV RNA. Positive ticks were detected in the provinces of Belluno and Vicenza and included individual adult males and nymph pools. A subset of positive samples was further characterized by nested PCR and Sanger sequencing of all four genomic segments. Phylogenetic analyses showed that Italian ALSV sequences clustered within the broader European ALSV diversity and were closely related to strains from Central and Northern Europe, without forming a distinct country-specific lineage. Sequence comparisons suggested purifying selection and revealed differences in predicted structural proteins between European and Chinese strains. These findings provide the first molecular evidence of ALSV circulation in Italy and support further studies to clarify its epidemiology, host range, genetic diversity, and potential clinical relevance. IMPORTANCEAlongshan virus (ALSV) is an emerging tick-borne virus identified in febrile patients in China and subsequently detected in ticks in Russian Federation and several European countries. Although severe disease has not yet been reported in humans, surveillance and elucidation of the virus distribution are essential to assess its pathogenicity and potential public health impact. We developed a specific real-time RT-PCR protocol and detected ALSV in Ixodes ricinus ticks collected in northeastern Italy. Sequence analyses suggested multiple introductions and revealed differences in structural proteins between European and Chinese strains, suggesting potential adaptation and differences in pathogenicity. Since the clinical signs of ALSV infection in humans may overlap with those of tick-borne encephalitis (TBE), differential diagnostic procedures should be developed to improve patient management, particularly in TBE-endemic regions such as northeastern of Italy.

microbiology↗

bioRxiv2023

Identification of druggable host dependency factors shared by multiple SARS-CoV-2 variants of concern

The high mutation rate of SARS-CoV-2 leads to emergence of several variants, some of which are resistant to vaccines and drugs targeting viral elements. Targeting host dependency factors - cell proteins required for viral replication - would help avoid resistance. However, whether different SARS-CoV-2 variants induce conserved cell responses and exploit the same core host factors is still unclear. We compared three variants of concern and observed that the host transcriptional response was conserved, differing only in kinetics and magnitude. By CRISPR screening we identified the host genes required for infection by each variant: most of the identified genes were shared by multiple variants, both in lung and colon cells. We validated our hits with small molecules and repurposed FDA-approved drugs. All drugs were highly effective against all tested variants, including delta and omicron, new variants that emerged during the study. Mechanistically, we identified ROS production as a pivotal step in early virus propagation. Antioxidant drugs, such as N-acetyl cysteine (NAC), were effective against all variants both in human lung cells, and in a humanised mouse model. Our study supports the use of available antioxidant drugs, such as NAC, as a general and effective anti-COVID-19 approach.

microbiology↗

bioRxiv2022

Isoform-specific O-glycosylation dictates Ebola virus infectivity

Ebola virus glycoprotein is one of the most heavily O-glycosylated viral envelope glycoproteins. Using glycoengineered cell lines we demonstrate that O-linked glycan truncation and perturbed initiation retarded the production of viral particles and decreased infectivity of progeny virus. Next, using TMT isobaric labelling, we performed quantitative differential O-glycoproteomics on proteins produced in wild type HEK293 cells and cell lines ablated for three key GalNAc-transferases, GalNAc-T1, -T2, and -T3, as well as compared it to patterns on wild type virus-like particles. We demonstrate selective initiation of a subset of O-glycosites by each enzyme, with GalNAc-T1 having the largest contribution. This work represents a comprehensive site-specific analysis of EBOV GP, with 47 O-glycosites identified, and sheds light on differential regulation of EBOV GP glycosylation initiated by host GalNAc-Ts. Together with the effect on viral propagation it opens prospective avenues for tailored intervention approaches and means for modulating immunogen O-glycan density.

microbiology↗

bioRxiv2021

A novel conformational state for SARS-CoV-2 main protease

The SARS-CoV-2 main protease (Mpro) has a pivotal role in mediating viral genome replication and transcription of coronavirus, making it a promising target for drugs against Covid-19 pandemic. Here we present a crystal structure of Mpro disclosing new structural features of key regions of the enzyme. We show that the oxyanion loop, involved in substrate recognition and enzymatic activity, can adopt a new conformation, which is stable and significantly different from the known ones. In this new state the S1 subsite of the substrate binding region is completely reshaped and a new cavity near the S2 subsite is created. This new structural information expands the knowledge of the conformational space available to Mpro, paving the way for the design of novel classes of inhibitors specifically designed to target this unprecedented binding site conformation, thus enlarging the chemical space for urgent antiviral drugs against Covid-19 pandemic.

biochemistry↗

bioRxiv2020

In-vitro virucidal activity of hypothiocyanite and hypothiocyanite/lactoferrin mix against SARS-CoV-2

SARS-CoV-2 replicates efficiently in the upper airway during prodromal stage with resulting viral shedding into the environment from patients with active disease as well as from asymptomatic individuals. So far, virus spread has been exclusively contained by non-pharmacological interventions (social distancing, face masks, hand washing and several measures limiting business activities or movement of individuals)1,2. There is a need to find pharmacological interventions to mitigate the viral spread, supporting yet limiting the existing health protection measures while an effective and safe vaccine will hopefully become available. Hypothiocyanite and lactoferrin as part of the innate human immune system were shown to have a large spectrum of cidal activity against bacteria, fungi and viruses2,3. To test their virucidal activity against SARS-CoV-2 we conducted an in-vitro study. Here we show a dose-dependent virucidal activity of hypothiocyanite at micromolar concentrations, slightly improved by the presence of lactoferrin. The two substances are devoid of any cytotoxicity and may be administered combined by aerosol to exploit their antiviral activity at the port of entry (mouth, nasal cavity, conjunctiva) or exit (mouth, through emission of respiratory droplets) of SARS-CoV-2 in the human body. Furthermore, aerosol with hypothiocyanite and lactoferrin combined could also have a therapeutic effect in the lower respiratory tract, at the level of gas exchange units of the lung, preventing the devastating infection of alveolar type II cells where ACE2 is highly expressed. An in-vivo validation of in-vitro results is urgently required.

microbiology↗