Development of functional antibodies against influenza B virus by activation-induced cytidine deaminase in hybridoma cells

Highlights
1. Class-switch recombination was mimicked in hybridomas through a controllable expression system of activation-induced cytidine deaminase.
2. IgG antibodies were generated through this system in an anti-Flu B IgM hybridoma 7G1.
3. IgG1 and IgG2a subtypes of 7G1 present improved antiviral activity in vitro and in vivo.     

Continued antigenic variation of highly pathogenic avian influenza A (H7N9) virus in laying hens in China, 2020–2021

Highlights
1. 13 strains of H7N9 viruses from laying hens in 2020 and 2021 were identified.
2. H7N9 viruses in China comprised at least 11 genotypes.
3. H7N9 viruses are high pathogenic in chickens, not in ducks.
4. The most H7N9 viruses cross-reacted poorly with H7-Re3 antiserum.
5. The H7-Re3 vaccine was unable to prevent H7N9 infection.     

The outbreak of rabbit hemorrhagic virus type 2 in the interior of China may be related to imported semen

Highlights:
1. We identified one RHD case caused by a new RHDV variant (GI.2) in China through HA, TEM, and genome sequencing.
2. This is the first study to demonstrate that GI.2 can replicate efficiently in the reproductive system.
3. Our evidence suggests that GI.2 might be introduced into China by contaminated rabbit semen.     

Rapid identification of QTLs underlying resistance to <Emphasis Type="Italic">Cucumber mosaic virus</Emphasis> in pepper (<Emphasis Type="Italic">Capsicum frutescens</Emphasis>)

Key message

Next-generation sequencing enabled a fast discovery of QTLs controlling CMV resistant in pepper. The gene CA02g19570 as a possible candidate gene of qCmr2.1 was identified for resistance to CMV in pepper.

Abstract

Cucumber mosaic virus (CMV) is one of the most important viruses infecting pepper, but the genetic basis of CMV resistance in pepper is elusive. In this study, we identified a candidate gene for CMV resistance QTL, qCmr2.1 through SLAF-seq. Segregation analysis in F₂, BC₁ and F_2:3 populations derived from a cross between two inbred lines ‘PBC688’ (CMV-resistant) and ‘G29’ (CMV-susceptible) suggested quantitative inheritance of resistance to CMV in pepper. Genome-wide comparison of SNP profiles between the CMV-resistant and CMV-susceptible bulks constructed from an F₂ population identified two QTLs, designated as qCmr2.1 on chromosome 2 and qCmr11.1 on chromosome 11 for resistance to CMV in PBC688, which were confirmed by InDel marker-based classical QTL mapping in the F₂ population. As a major QTL, joint SLAF-seq and traditional QTL analysis delimited qCmr2.1 to a 330 kb genomic region. Two pepper genes, CA02g19570 and CA02g19600, were identified in this region, which are homologous with the genes LOC104113703, LOC104248995, LOC102603934 and LOC101248357, which were predicted to encode N-like protein associated with TMV-resistant in Solanum crops. Quantitative RT-PCR revealed higher expression levels of CA02g19570 in CMV resistance genotypes. The CA02g19600 did not exhibit obvious regularity in expression patterns. Higher relative expression levels of CA02g19570 in PBC688 and F₁ were compared with those in G29 during days after inoculation. These results provide support for CA02g19570 as a possible candidate gene of qCmr2.1 for resistance to CMV in pepper.

     

Dumpy-30 family members as determinants of male fertility and interaction partners of metal-responsive transcription factor 1 (MTF-1) in Drosophila

Background

Human clinical studies and mouse models clearly demonstrate that cytomegalovirus (CMV) disrupts normal organ and tissue development. Although CMV is one of the most common causes of major birth defects in humans, little is presently known about the mechanism(s) underlying CMV-induced congenital malformations. Our prior studies have demonstrated that CMV infection of first branchial arch derivatives (salivary glands and teeth) induced severely abnormal phenotypes and that CMV has a particular tropism for neural crest-derived mesenchyme (NCM). Since early embryos are barely susceptible to CMV infection, and the extant evidence suggests that the differentiation program needs to be well underway for embryonic tissues to be susceptible to viral infection and viral-induced pathology, the aim of this study was to determine if first branchial arch NCM cells are susceptible to mCMV infection prior to differentiation of NCM derivatives.

Results

E11 mouse mandibular processes (MANs) were infected with mouse CMV (mCMV) for up to 16 days in vitro. mCMV infection of undifferentiated embryonic mouse MANs induced micrognathia consequent to decreased Meckel's cartilage chondrogenesis and mandibular osteogenesis. Specifically, mCMV infection resulted in aberrant stromal cellularity, a smaller, misshapen Meckel's cartilage, and mandibular bone and condylar dysmorphogenesis. Analysis of viral distribution indicates that mCMV primarily infects NCM cells and derivatives. Initial localization studies indicate that mCMV infection changed the cell-specific expression of FN, NF-κB2, RelA, RelB, and Shh and Smad7 proteins.

Conclusion

Our results indicate that mCMV dysregulation of key signaling pathways in primarily NCM cells and their derivatives severely disrupts mandibular morphogenesis and skeletogenesis. The pathogenesis appears to be centered around the canonical and noncanonical NF-κB pathways, and there is unusual juxtaposition of abnormal stromal cells and surrounding matrix. Moreover, since it is critically important that signaling molecules are expressed in appropriate cell populations during development, the aberrant localization of components of relevant signaling pathways may reveal the pathogenic mechanism underlying mandibular malformations.     

A method for the synthesis of C-(2-deoxy-β-glycosyl) arenes

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(2) was converted by a Wittig reaction into a mixture of (

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(4,5). Selective deprotection of the 5,6-O-isopropylidene group in compounds 4 and 5 followed by selective silylation at position 6 afforded the separate

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8a–d and the corresponding E-isomers (9a–d). Iodonium-ion-induced cyclization of compounds 8c and 9a-c furnished stereoselectively the

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10a–c. Full deprotection of compounds 10a–c and the O-acetylation led to compounds 11a–c, which on treatment with tributyltin hydride-azobisisobutyromnitrile yielded and the title compounds (12a–c).     

Identification of a novel hepacivirus in Mongolian gerbil (Meriones unguiculatus) from Shaanxi,China

Highlights:
1. The first hepacivirus detected in Mongolian gerbils from a plague zones in China.
2. A novel hepacivirus closely related to hepacivirus E and F.
3. Mongolian gerbils could be a potential animal model for hepacivirus pathogenicity.
4. Extending the genetic diversity and host range of hepaciviruses.     

DNA sequence-specific ligands. XVII. Synthesis,spectral properties,virological and biochemical studies of fluorescent dimeric bisbenzimidazoles DBA(n)

A series of DNA minor groove binding fluorescent dimeric bisbenzimidazoles DBA(n) bearing linkers of various length were synthesized and their biochemical and antiviral activities were evaluated. Their antiviral activity was assessed in model cell systems infected with human herpes simplex virus (HSV-1) and cytomegalovirus (CMV). Compounds DBA(1) and DBA(7) demonstrated in vitro inhibitory properties towards HSV-1, and DBA(7) completely blocked the viral infection. Compound DBA(11) displayed the in vitro therapeutic activity towards both HSV-1 and CMV. All of the DBA(n) could fluoresce, were well soluble in water, not cytotoxic to a concentration of 240?µM, penetrated well into cell nuclei by binding to DNA and could inhibit topo-I at low micromolecular concentrations.     

Severe acute hepatitis in children with unknown aetiology,etiology analysis and the next action

Highlights
1. MIS-C and severe acute hepatitis might share the common pathogenic mechanism;
2. SARS-CoV-2 persistence throughout multiorgan and tissues;
3. Relationship between COVID-19 vaccines and severe acute hepatitis worth investigating.     

The synthesis and structure-activity relationship of pyridazinones as glucan synthase inhibitors

A structure-activity relationship study of the lead 5-[4-(benzylsulfonyl)piperazin-1-yl]-4-morpholino-2-phenyl-pyridazin-3(2H)-one 1 has resulted in the identification of 2-(3,5-difluorophenyl)-4-(3-fluorocyclopentyloxy)-5-[4-(isopropylsulfonyl)piperazin-1-yl]-pyridazin-3(2H)-one 11c as a β-1,3-glucan synthase inhibitor. Compound 11c exhibited significant efficacy in an in vivo mouse model of Candida glabrata infection.     

New discovery of high-affinity SARS-CoV-2 spike S2 protein binding peptide selected by PhIP-Seq

Highlights
1 A peptide Spep-1 targeting S2 of SARS-CoV-2 spike protein was selected by PhIP-Seq.
2 Spep-1 showed nanomolar affinity and high specificity to spike protein.
3 S-1 based immunoassay can detect femtomolar spike antigen in spiked serum samples.
4 Spep-1 can be used in future on S2 recognition, virus tracing and drug delivery.     

Cytomegalovirus and Herpes Simplex Virus Effect on the Prognosis of Mechanically Ventilated Patients Suspected to Have Ventilator-Associated Pneumonia

Objective

Cytomegalovirus (CMV) and herpes simplex virus (HSV) are common viruses that can affect critically ill patients who are not immunocompromised. The aim of this study was to determine whether the identification of CMV and/or HSV in mechanically ventilated critically ill patients suspected of having pneumonia was associated with an increased mortality.

Design

Prospective epidemiological study.

Setting

Medical intensive care unit of a tertiary medical center.

Patients

Ninety-three patients with suspected pneumonia.

Interventions

Patients with suspected pneumonia had bronchoalveolar lavage and blood samples taken to confirm the diagnosis. Antigenemia was used to detect CMV in the blood. Bronchoalveolar lavage samples were submitted to testing using quantitative real-time Polymerase Chain Reaction.

Measurements and Main Results

We identified 22 patients with a CMV infection, 26 patients with an HSV infection and 45 patients without CMV or HSV infection (control group). Mortality at day 60 was higher in patients with a CMV infection than in patients from the control group (55% vs. 20%, P<0.01). Mortality at day 60 was not significantly increased in the group with HSV infection. Duration of ICU stay and ICU mortality were significantly higher in patients with CMV infections when compared to patients from the control group, whereas ventilator free days were significantly lower in patients with CMV infections when compared to patients from the control group.

Conclusions

In critically ill patients, a CMV infection is associated with an increased mortality. Further interventional studies are needed to evaluate whether treatment could improve the prognosis.     

Emergence of H5N8 avian influenza virus in domestic geese in a wild bird habitat,Yishui Lake,north central China

Highlights
1. H5N8 viruses emerged in the wild bird habitat at Yishui Lake.
2. The homology between HG12 and a Russian human strain was over 99%.
3. HG12 can be transmitted through direct contact between guinea pigs.     

Similar aerosol emission rates and viral loads in upper respiratory tracts for COVID-19 patients with Delta and Omicron variant infection

Highlights
1 Aerosol emission rates of Delta or Omicron patients were similar.
2 Viral loads in upper respiratory tract of Alpha, Delta and Omicron patients were similar.
3 Viral loads in upper respiratory tract of vaccinated or unvaccinated Delta patients had no difference.     

Immunization of mice with vaccinia virus Tiantan strain yields antibodies cross-reactive with protective antigens of monkeypox virus

Highlights
1. The first study describing the cross-reactivity of antibodies elicited by a Chinese smallpox vaccine against monkeypox virus.
2. Mice immunized with vaccinia virus Tiantan strain yield antibodies cross-reactive with monkeypox virus protective antigens.
3. Cross-reactivities of VTT-elicited antibodies against monkeypox protective antigens are ranging from 33% to 94%.     

Development of rapid nucleic acid assays based on the recombinant polymerase amplification for monkeypox virus

Highlights
1. Two RPA methods (F-RPA and VF- RPA) have been developed for monkeypox virus rapid detection.
2. The limit of detection was 15.32 copies/μL for F-RPA and 8.53 copies/μL for VF-RPA,
3. No cross-reaction was found in 14 rash and fever-associated viruses.
4. The two RPA methods developed are simple and rapid, making them potentially useful for detection of MPXV in the field/clinic.     

HCV 6a was expanding and became the predominant subtype among blood donors between 2004 and 2019 in Guangdong,China

Highlights
1. Currently, HCV 6a has replaced 1b as the most prevalent subtype in blood donors in Guangdong.
2. HCV 6a was the predominant subtype in males and older donors, while 1b predominated in females and younger donors.
3. HCV 6a may expand from Guangdong to other districts of China, and is worthy of attention     

Development of stable,cold-adapted,temperature-sensitive/conditional lethal chimeric enterovirus A71 and coxsackievirus A16

Highlights
1 A stable EV-A71 virus vector was created to generate chimeric enterovirus strains expressing capsid protein genes of EV-A71 subgenogroup C5 and CA16.
2 Phenotypic and genetic stability of the generated chimeric EV-A71 and CA16 were analyzed.
3 The amino acids at the cleavage site between VP1 and 2A is crucial for stability.     

Efficient and high-throughput pseudorecombinant-chimeric Cucumber mosaic virus-based VIGS in maize

Virus-induced gene silencing (VIGS) is a versatile and attractive approach for functional gene characterization in plants. Although several VIGS vectors for maize (Zea mays) have been previously developed, their utilities are limited due to low viral infection efficiency, insert instability, short maintenance of silencing, inadequate inoculation method, or abnormal requirement of growth temperature. Here, we established a Cucumber mosaic virus (CMV)-based VIGS system for efficient maize gene silencing that overcomes many limitations of VIGS currently available for maize. Using two distinct strains, CMV-ZMBJ and CMV-Fny, we generated a pseudorecombinant-chimeric (Pr) CMV. Pr CMV showed high infection efficacy but mild viral symptoms in maize. We then constructed Pr CMV-based vectors for VIGS, dubbed Pr CMV VIGS. Pr CMV VIGS is simply performed by mechanical inoculation of young maize leaves with saps of Pr CMV-infected Nicotiana benthamiana under normal growth conditions. Indeed, suppression of isopentenyl/dimethylallyl diphosphate synthase (ZmIspH) expression by Pr CMV VIGS resulted in non-inoculated leaf bleaching as early as 5 d post-inoculation (dpi) and exhibited constant and efficient systemic silencing over the whole maize growth period up to 105 dpi. Furthermore, utilizing a ligation-independent cloning (LIC) strategy, we developed a modified Pr CMV-LIC VIGS vector, allowing easy gene cloning for high-throughput silencing in maize. Thus, our Pr CMV VIGS system provides a much-improved toolbox to facilitate efficient and long-duration gene silencing for large-scale functional genomics in maize, and our pseudorecombination-chimera combination strategy provides an approach to construct efficient VIGS systems in plants.

A pseudorecombinant-chimeric Cucumber mosaic virus-based virus-induced gene silencing system rapidly and efficiently triggers persistent gene silencing in maize.