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Innate Immune Mechanisms Triggered by SARS-CoV-2 Virus-Like Particles: Role of Antibody Opsonization.

The rapid spread of SARS-CoV-2 highlighted the need to understand the nature of innate immune signaling. We used virus-like particles (VLPs) composed of SARS-CoV-2 structural proteins, spike, envelope, membrane, and nucleocapsid, mimicking the virus to study macrophage responses to VLPs and their immune complexes (ICs), which represent antibody-opsonized particles cleared by innate immune cells. We assessed antibody affinity and IC properties using quartz crystal microbalance with dissipation (QCM-D). Human THP-1-derived macrophages treated with VLPs or ICs showed inflammatory activation, incl…

25 Years of Ebola Virus VP35 Research.

Ebola virus (EBOV) is a highly virulent non-segmented, negative-sense RNA virus and a causative agent of severe, often fatal disease in humans. EBOV encodes 7 genes and viral protein 35 (VP35) plays a key role in EBOV pathogenesis. VP35 is an EBOV polymerase cofactor that facilitates host immune evasion, viral RNA synthesis, and nucleocapsid assembly. Over the past 25 years since the first recognition that VP35 can antagonize innate immune responses, considerable progress has been made to define the molecular mechanisms by which VP35 mediates its multiple functions and interactions with host f…

False positive serology of prepandemic chagasic samples with SARS-CoV-2 antigen.

OBJECTIVE: To determine whether prepandemic sera from patients with Chagas disease recognise SARS-CoV-2 antigens. MATERIALS AND METHODS: Forty sera from patients with Chagas disease were tested for the presence of IgG cross-reactivity against the nucleocapsid protein (NP) and spike (S) SARS-CoV-2 proteins by ELISA. Positive samples were tested again using a different ELISA and CLIA, both against NP. RESULTS: None of the sera from patients with Chagas disease, previously confirmed as positive for the presence of anti-Trypanosoma cruzi antibodies reacted against the SARS-CoV-2 S protein, and s…

First case of postmortem study in a patient vaccinated against SARS-CoV-2.

A previously symptomless 86-year-old man received the first dose of the BNT162b2 mRNA COVID-19 vaccine. He died 4 weeks later from acute renal and respiratory failure. Although he did not present with any COVID-19-specific symptoms, he tested positive for SARS-CoV-2 before he died. Spike protein (S1) antigen-binding showed significant levels for immunoglobulin (Ig) G, while nucleocapsid IgG/IgM was not elicited. Acute bronchopneumonia and tubular failure were assigned as the cause of death at autopsy; however, we did not observe any characteristic morphological features of COVID-19. Postmortem…

Development of a multi-antigenic SARS-CoV-2 vaccine candidate using a synthetic poxvirus platform.

Modified Vaccinia Ankara (MVA) is a highly attenuated poxvirus vector that is widely used to develop vaccines for infectious diseases and cancer. We demonstrate the construction of a vaccine platform based on a unique three-plasmid system to efficiently generate recombinant MVA vectors from chemically synthesized DNA. In response to the ongoing global pandemic caused by SARS coronavirus-2 (SARS-CoV-2), we use this vaccine platform to rapidly produce fully synthetic MVA (sMVA) vectors co-expressing SARS-CoV-2 spike and nucleocapsid antigens, two immunodominant antigens implicated in protective …

Mutational profiling of the variability of individual amino acid positions in the hepatitis B virus matrix domain.

The hepatitis B virus (HBV) is formed by budding. A stretch of 22 amino acids (aa) (matrix domain, MD, R103 - S124) in the large envelope protein L is crucial for virion formation and probably establishes contact to the nucleocapsid. Here, we assess the impact of sequence variations at numerous individual aa positions within the MD on virion formation. We generated panels of L mutants covering all 19 possible aa for 11 positions and tested the capacity of these mutants to rescue virus production by an L-defective HBV genome. At four positions (L112, R113, P117, W122), any replacement of the wi…

ELISA and direct immunofluorescence test to detect equine arteritis virus (EAV) using a monoclonal antibody directed to the EAV-N protein.

A monoclonal antibody (mAb) directed against the equine arteritis virus (EAV) nucleocapsid (N) protein was used for indirect enzyme-linked immunosorbent assays (ELISAs) using viral antigen from different sources. The same mAb was labelled with fluorescein isothiocyanate for direct immunofluorescence tests (DIFTs). The N-specific mAb appeared to be suitable for the detection in both ELISA and DIFT of different EAV strains and field isolates from semen and tissue samples after passage in lines of RK-13, Vero and fetal equine kidney cells. The ELISA described is an easy and fast method which can …

The 36K polypeptide synthesized in Newcastle disease virus-infected cells possesses properties predicted for the hypothesized 'V' protein.

Newcastle disease virus (NDV) virions possess two proteins which react strongly with monoclonal antibody 688 following separation by high resolution two-dimensional (isoelectric focusing/SDS) PAGE and detection by Western blotting. One is the phosphorylated nucleocapsid-associated 53K [P (NAP)] protein, the other comigrates with the 36K protein detected by radiolabelling NDV-infected chick embryo fibroblasts. [35S]Cysteine/[3H]leucine dual-labelling experiments show that the 36K protein is very rich in cysteine compared to the P (NAP) protein. In the Beaudette C strain it comigrates on one-dim…

Multigenic relation to the attenuation of rabies virus.

Rabies virus Nishigahara strain causes lethal infection in adult mice after intracerebral inoculation. On the other hand, the RC-HL strain, derived from the Nishigahara strain, does not cause lethal infection in adult mice. We previously demonstrated that a chimeric virus, R(G), with the open reading frame of the G gene (G-ORF) from the Nishigahara strain in the background of the RC-HL genome, is virulent. Reversely, in order to demonstrate that the G gene of the RC-HL strain is related to the attenuated phenotype, we established a reverse genetics system of the Nishigahara strain and generate

Inhibition of hepatitis B virus replication during adenovirus and cytomegalovirus infections in transgenic mice.

We have previously demonstrated that hepatitis B virus (HBV) replication and gene expression are abolished in the livers of HBV transgenic mice by cytotoxic T lymphocytes (CTLs) and during lymphocytic choriomeningitis virus (LCMV) infection, stimuli that trigger the production of alpha/beta interferon, gamma interferon, and tumor necrosis factor alpha in the liver. We now report that hepatic HBV replication and gene expression are inhibited by the local induction of these cytokines during adenovirus- and murine cytomegalovirus (MCMV)-induced hepatitis. Further, we show that MCMV also blocks HB

Почему вирус Эболы не вызывает пандемий вроде SARS-COV-2?

Вирус Эболы является одной из наиболее опасных, инфекционных и смертоносных этиологических причин вирусных заболеваний. Однако вирус Эболы никогда не широко распространялся среди населения и никогда не приводил к пандемии. Почему? Механистическая биофизическая модель, иллюстрирующая биотермодинамический фон взаимодействия вируса с призраком), могла бы помочь нам понять патогенез вируса Эбола (ранее известного как геморрагическая лихорадка Эболы). В настоящем документе впервые сообщается эмпирическая формула, термодинамические свойства биосинтеза (включая движущую силу умножения вируса в чувств

Совпадение в аннотации оригинала
Ebola virus is among the most dangerous, contagious and deadly etiological causes of viral diseases. However, Ebola virus has never extensiv … be CH1.569O0.3281N0.2786P0.00173S0.00258. Standard Gibbs energy of biosynthesis of the Ebola virus nucleocapsid is -151.59 kJ/C-mol.

Research Note: Duck plague virus glycoprotein I influences cell-cell spread and final envelope acquisition.

To determine the role of glycoprotein I (gI) in duck plague virus (DPV), a gI-deleted mutant (BAC-CHv-ΔgI) and a gI-revertant virus (BAC-CHv … BAC-CHv-ΔgI Rev and wild-type virus. Electron microscopy confirmed that deleting of gI resulted in nucleocapsids accumulated around the cytoplasm vesicles and few of them could complete the final envelopment process. These results clearly indicated that DPV gI plays significant roles in viral cell-cell spread and viral final envelopment process.

Deficient humoral responses and disrupted B-cell immunity are associated with fatal SFTSV infection.

Severe Fever with Thrombocytopenia Syndrome (SFTS), an emerging infectious disease caused by a novel phlebovirus, is associated with high fa … . The serological profile in deceased patients is characterized by absence of specific IgG to viral nucleocapsid and glycoprotein due to failure of B-cell class switching. Expansion and impairment of antibody secretion is a signature of fatal SFTSV infection. Apoptosis of monocytes in the early stage of infection diminishes antigen-presentation by dendritic ce …

Insights into the function of tegument proteins from the varicella zoster virus.

Chickenpox (varicella) is caused by primary infection with varicella zoster virus (VZV), which can establish long-term latency in the host ganglion. Once reactivated, the virus can cause shingles (zoster) in the host. VZV has a typical herpesvirus virion structure consisting of an inner DNA core, a capsid, a tegument, and an outer envelope. The tegument is an amorphous layer enclosed between the nucleocapsid and the envelope, which contains a variety of proteins. However, the types and functions of VZV tegument proteins have not yet been completely determined. In this review, we describe the c…

Отрицательно заряженные остатки в эндодомене имеют решающее значение для конкретного соединения белка шипа в муринный коронавирус.

Протеин коронавируса (S) соединяется с вирионами через карбокситермин, который состоит из трансмембранной области и эндодомена. Здесь было установлено, что движущая сила, богатая зарядом в эндодомене, имеет решающее значение для специфичности S-комбинации в вирусе гепатита мыши (MHV). Рекомбинантные MHV продемонстрировали ряд возможностей для размещения гомологовых S-эндоводов из бета-коронавирусов говяжьего коронавируса и человека, связанного с SARS, коронавируса, альфакоронавирусного трансмиссивного гастроэнтерита (TGEV) и гаммакоронавируса птичьего инфекционного бронхита, соответственно. Ин

Совпадение в аннотации оригинала
Coronavirus spike (S) protein assembles into virions via its carboxy-terminus, which is composed of a transmembrane domain and an endodomain … nt. Additionally, MHV S assembly could also be rescued by the acidic carboxy-terminal domain of the nucleocapsid protein. These results indicate an important role for negatively charged endodomain residues in the incorporation of MHV S protein into assembled virions.

Hsp70 protein positively regulates rabies virus infection.

The Hsp70 chaperone plays a central role in multiple processes within cells, including protein translation, folding, intracellular trafficking, and degradation. This protein is implicated in the replication of numerous viruses. We have shown that rabies virus infection induced the cellular expression of Hsp70, which accumulated in Negri body-like structures, where viral transcription and replication take place. In addition, Hsp70 is present in both nucleocapsids purified from infected cells and in purified virions. Hsp70 has been shown to interact with the nucleoprotein N. The downregulation o…

Role of tegument proteins in herpesvirus assembly and egress.

Morphogenesis and maturation of viral particles is an essential step of viral replication. An infectious herpesviral particle has a multilayered architecture, and contains a large DNA genome, a capsid shell, a tegument and an envelope spiked with glycoproteins. Unique to herpesviruses, tegument is a structure that occupies the space between the nucleocapsid and the envelope and contains many virus encoded proteins called tegument proteins. Historically the tegument has been described as an amorphous structure, but increasing evidence supports the notion that there is an ordered addition of teg…

Inhibition of measles virus infections in cell cultures by peptide-conjugated morpholino oligomers.

Measles virus (MeV) is a highly contagious human pathogen. Despite the success of measles vaccination programs, measles is still responsible … (PPMO 454), targeting a conserved sequence in the translation start site of the mRNA coding for the nucleocapsid protein, inhibited multiple genotypes of MeV. This report provides evidence that PPMO treatment represents a promising approach for developing antiviral agents against measles and other paramyxoviruses.

HA2 from the Helicoverpa armigera nucleopolyhedrovirus: a WASP-related protein that activates Arp2/3-induced actin filament formation.

Filamentous actin is required for the productive replication of lepidopteran nucleopolyhedroviruses. We have demonstrated that nucleocapsids of the Helicoverpa armigera nucleopolyhedrovirus (HearNPV) are capable of nucleating actin polymerization in vitro in a dose-dependent manner. Actin polymerization is the main mechanism used in cell locomotion and is also utilized by the Listeria bacteria and by vaccinia virus for intracellular and intercellular movements. The WASP family of proteins has been shown to stimulate the assembly of branched actin filaments by the Arp2/3 complex. The process is…

Rapid field test for detection of hantavirus antibodies in rodents.

Puumala virus (PUUV) is the causative agent of nephropathia epidemica, a mild form of haemorrhagic fever with renal syndrome. PUUV is transmitted to humans via aerosolized excreta of the infected bank vole (Clethrionomys glareolus). Current methods for screening of the PUUV prevalence among bank vole populations are laborious, combining sampling in the field and subsequent analyses in the laboratory. In order to facilitate animal testing, a new serological immunochromatographic rapid test was developed. The test uses PUUV nucleocapsid protein as antigen, and it detects anti-PUUV IgG antibodies…