Identification of a potential interspecies reassortant rotavirus G and avastrovirus 2 co-infection from black-headed gull (Chroicocephalus ridibundus) in HungaryPankovics, Takáts, Urbán
et alPLoS One (2025) 20 (3), e0317400
Abstract: The black-headed gull is the most common nesting gull species in Hungary. Based on the lifestyle and feeding habits of the black-headed gull, which is highly adapted to the human environment, they can be carriers and spreaders of potential human and other animal pathogens. Between 2014 and 2018 within the framework of the "Life Bird Ringing program" a total of 7 faecal samples were collected from gulls and one sample (MR04) was randomly selected for viral metagenomics and mass sequencing. 95.4% and 4% of the reads were classified into family Seadornaviridae and Astroviridae, respectively, and then were verified by RT-PCR method. In this study, the complete genome of a potential interspecies reassortant rotavirus (RV) strain gull/MR04_RV/HUN/2014 (PP239049-PP239059) and the partial ORF1ab, complete ORF2 of a novel avian nephritis virus strain gull/MR04_AAstV/HUN/2014 (PP239060) was discussed. The strain gull/MR04_RV/HUN/2014 was closely related to rotavirus G (RVG) viruses based on the proteins VP1-VP3, VP6, NSP2, NSP3, and NSP5, but it was more related to the human rotavirus B (RVB) strain Bang373 based on the NSP1, NSP4 and VP7, VP4 proteins, which is assumed to be the result of reassortment between different RVG-RVB rotavirus species. The strain gull/MR04_AAstV/HUN/2014 belonged to the genus Avastrovirus species avastrovirus 2 (AAstV-2) and is related to members of group 6 of avian nephritis viruses (ANVs), but based on the genetic distances it may be the first representative of a separate group. Additional gull samples were found to be negative by RT-PCR. Gulls, which are well adapted to the human environment, could potentially spread enterically transmitted viral pathogens like interspecies reassortant rotaviruses (RVG/RVB), but further molecular surveillance is needed to explore more deeply the viral communities of gulls or other related species adapted to human environments.Copyright: © 2025 Pankovics et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Distinct roles of SARS-CoV-2 N protein and NFP in host cell response modulationLan, Hou, Chang
et alJ Mol Biol (2025)
Abstract: The SARS-CoV-2 nucleocapsid (N) protein is crucial for viral replication and modulation of host cell responses. Here, we identify and characterize a novel N-fusion protein, designated NFP. NFP is derived from an alternative open reading frame spanning the N gene and the non-structural protein 1 (NSP1) sequence. While NFP shares some functional domains with the canonical N protein, it exhibits distinct structural features and protein interactions. NFP retains the ability to dimerize and bind RNA but lacks the formation of biomolecular condensates associated with N. Notably, NFP can dominantly interfere with N's condensate formation capacity when co-expressed. Functionally, NFP partially suppresses stress granule (SG) formation through a G3BP1-independent mechanism but gains the ability to interact with G3BP1 in the presence of N, potentially through N-NFP heterodimer formation. Post-translational modifications, particularly ubiquitination of specific lysine residues (K374 in N and K502 in NFP), differentially regulate the subcellular localization, SG inhibition, and cell cycle regulation activities of N and NFP. Our findings establish NFP as a distinct viral effector protein that modulates host cellular environments through both conserved and unique mechanisms compared to the canonical N protein, providing insights into SARS-CoV-2 pathogenesis and potential therapeutic targets.Copyright © 2025 Elsevier Ltd. All rights reserved.
Attenuation of Chikungunya Virus by a Single Amino Acid Substitution in the nsP1 Component of a Non-Structural PolyproteinChamberlain, Dowall, Smith
et alViruses (2025) 17 (2)
Abstract: Chikungunya virus (CHIKV) is a mosquito-transmitted alphavirus that, since its re-emergence in 2004, has become recognised as a major public health concern throughout many tropical and sub-tropical regions of the world. Amongst the insights gained from studies on other alphaviruses, several key determinants of virulence have been identified, including one present at the P3 position in the nsP1/nsP2 cleavage domain of the S.A.AR86 Sindbis (SINV) strain. This strain is associated with neurovirulence in adult mice; however, when a threonine-to-isoleucine substitution is engineered at this P3 position, an attenuated phenotype results. A reverse genetics system was developed to evaluate the phenotype that resulted from the substitution of alanine, present at the P3 position in the wild-type CHIKV clone, with valine. The A533V-mutant CHIKV induced milder disease symptoms in the C57BL/6 mouse model than the wild-type virus, in terms of severity of inflammation, length of viraemic period, and histological changes. Furthermore, the induction of type I IFN occurred more rapidly in both CHIKV-infected cell cultures and the mouse model with the mutant CHIKV.
In Vitro Evaluation of the Antiviral Activity of Polyphenol (-)-Epigallocatechin-3-Gallate (EGCG) Against Mayaro Virusda Conceição, Ayusso, Carvalho
et alViruses (2025) 17 (2)
Abstract: The Mayaro virus (MAYV), Togaviridae family, genus Alphavirus, has caused several sporadic outbreaks, affecting countries in the Americas. Currently, there are no licensed drugs against MAYV, requiring the search for effective antiviral compounds. Thus, this study aimed to evaluate the antiviral potential of polyphenol (-)-epigallocatechin-3-gallate (EGCG) against MAYV infection, in vitro. Antiviral assays against MAYV were performed in BHK-21 and Vero E6 cells. In addition, molecular docking was performed with EGCG and the MAYV non-structural and structural proteins. EGCG showed a significant protective effect against MAYV infection in both cell lines. The virucidal assay showed an effect on extracellular viral particles at the entry stage into BHK-21 cells. Finally, it also showed significant inhibition in the post-entry stages of the MAYV replication cycle, acting on the replication of the genetic material and late stages, such as assembly and release. In addition, the MAYV proteins E1 and nsP1 were significantly inhibited by the EGCG treatment in BHK-21 cells. Molecular docking analysis also showed that EGCG could interact with MAYV Capsid and Envelope proteins (E1 and E2). Therefore, this study shows the potential of EGCG as a promising antiviral against MAYV, as it acts on different stages of the MAYV replication cycle.
膜杰作
Star Staining
