scholarly journals Survival of Escherichia coli harboring nucleic acid-hydrolyzing 3D8 scFv during RNA virus infection

2018 ◽  
Vol 94 ◽  
pp. 286-292 ◽  
Author(s):  
Jung-Ho Park ◽  
Jae-Woo Lee ◽  
Hoonsung Choi ◽  
Sun Keun Jung ◽  
Jeom Sun Kim ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Nucleic Acid ◽  
Virus Infection ◽  
Rna Virus ◽  
3D8 Scfv

scholarly journals Cellular nucleic acid–binding protein is essential for type I interferon–mediated immunity to RNA virus infection

2021 ◽  
Vol 118 (26) ◽  
pp. e2100383118
Author(s):  
Yongzhi Chen ◽  
Xuqiu Lei ◽  
Zhaozhao Jiang ◽  
Katherine A. Fitzgerald
Keyword(s):  
Gene Expression ◽  
Nucleic Acid ◽  
Virus Infection ◽  
Rna Virus ◽  
Innate Immune ◽  
Type I ◽  
Type I Ifn ◽  
Nucleic Acid Binding ◽  
Nucleic Acid Binding Protein ◽  
Acid Binding Protein

Type I interferons (IFNs) are innate immune cytokines required to establish cellular host defense. Precise control of IFN gene expression is crucial to maintaining immune homeostasis. Here, we demonstrated that cellular nucleic acid–binding protein (CNBP) was required for the production of type I IFNs in response to RNA virus infection. CNBP deficiency markedly impaired IFN production in macrophages and dendritic cells that were infected with a panel of RNA viruses or stimulated with synthetic double-stranded RNA. Furthermore, CNBP-deficient mice were more susceptible to influenza virus infection than were wild-type mice. Mechanistically, CNBP was phosphorylated and translocated to the nucleus, where it directly binds to the promoter of IFNb in response to RNA virus infection. Furthermore, CNBP controlled the recruitment of IFN regulatory factor (IRF) 3 and IRF7 to IFN promoters for the maximal induction of IFNb gene expression. These studies reveal a previously unrecognized role for CNBP as a transcriptional regulator of type I IFN genes engaged downstream of RNA virus–mediated innate immune signaling, which provides an additional layer of control for IRF3- and IRF7-dependent type I IFN gene expression and the antiviral innate immune response.

Infection of Escherichia coli with bacteriophages

1969 ◽  
Vol 27 ◽  
pp. 370-371
Author(s):  
Manfred E. Bayer
Keyword(s):  
Escherichia Coli ◽  
Nucleic Acid ◽  
Cell Surface ◽  
Virus Type ◽  
Infection Process ◽  
Adsorption Site ◽  
The Other ◽  
Specific Receptors ◽  
Bacterial Receptors

The first step in the infection of a bacterium by a virus consists of a collision between cell and bacteriophage. The presence of virus-specific receptors on the cell surface will trigger a number of events leading eventually to release of the phage nucleic acid. The execution of the various "steps" in the infection process varies from one virus-type to the other, depending on the anatomy of the virus. Small viruses like ØX 174 and MS2 adsorb directly with their capsid to the bacterial receptors, while other phages possess attachment organelles of varying complexity. In bacteriophages T3 (Fig. 1) and T7 the small conical processes of their heads point toward the adsorption site; a welldefined baseplate is attached to the head of P22; heads without baseplates are not infective.

scholarly journals Are RNA-Based Tests Sufficient for COVID-19 Diagnosis? An Inspiration of Three Asymptomatic Cases

2021 ◽  
Vol 30 ◽  
pp. 096368972098545
Author(s):  
Tao Hu ◽  
Xiao Liu ◽  
Qinan Yin ◽  
Xingting Duan ◽  
Li Yan
Keyword(s):  
Computed Tomography ◽  
Nucleic Acid ◽  
Virus Infection ◽  
Severe Acute Respiratory Syndrome ◽  
The Other ◽  
Computed Tomography Scan ◽  
Health Authorities ◽  
History Of ◽  
Tomography Scan ◽  
Nucleic Acid Tests

In this work, we discovered a new phenomenon—asymptomatic COVID-19 infection, or covert case, during the pandemic. All the 3 patients had a history of exposure, with no symptoms, and no abnormalities were found in computed tomography scan or lab tests. Except for case 2, the other patients’ severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) nucleic acid tests were negative. But their anti-SARS-COV-2 nucleocapsid antibody showed a dynamic trend, consistent with the process of virus infection and clearance. A growing number of asymptomatic or covert cases need more attention. Lack of surveillance may lead to another outbreak. We hope to demonstrate our cases to attract the attention of governments or health authorities that covert cases should be the focus as well.

scholarly journals Broad-Spectrum Antiviral Activity of 3D8, a Nucleic Acid-Hydrolyzing Single-Chain Variable Fragment (scFv), Targeting SARS-CoV-2 and Multiple Coronaviruses In Vitro

Viruses ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 650
Author(s):  
Gunsup Lee ◽  
Shailesh Budhathoki ◽  
Geum-Young Lee ◽  
Kwang-ji Oh ◽  
Yeon Kyoung Ham ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Antiviral Activity ◽  
Broad Spectrum ◽  
Recombinant Antibody ◽  
Therapeutic Effects ◽  
Single Chain Variable Fragment ◽  
Single Chain ◽  
Diarrhea Virus ◽  
3D8 Scfv

The virus behind the current pandemic, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the etiology of novel coronavirus disease (COVID-19) and poses a critical public health threat worldwide. Effective therapeutics and vaccines against multiple coronaviruses remain unavailable. Single-chain variable fragment (scFv), a recombinant antibody, exhibits broad-spectrum antiviral activity against DNA and RNA viruses owing to its nucleic acid-hydrolyzing property. The antiviral activity of 3D8 scFv against SARS-CoV-2 and other coronaviruses was evaluated in Vero E6 cell cultures. Viral growth was quantified with quantitative RT-qPCR and plaque assay. The nucleic acid-hydrolyzing activity of 3D8 was assessed through abzyme assays of in vitro viral transcripts and cell viability was determined by MTT assay. We found that 3D8 inhibited the replication of SARS-CoV-2, human coronavirus OC43 (HCoV-OC43), and porcine epidemic diarrhea virus (PEDV). Our results revealed the prophylactic and therapeutic effects of 3D8 scFv against SARS-CoV-2 in Vero E6 cells. Immunoblot and plaque assays showed the reduction of coronavirus nucleoproteins and infectious particles, respectively, in 3D8 scFv-treated cells. These data demonstrate the broad-spectrum antiviral activity of 3D8 against SARS-CoV-2 and other coronaviruses. Thus, it could be considered a potential antiviral countermeasure against SARS-CoV-2 and zoonotic coronaviruses.

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