scholarly journals Single-chain variable fragment antibody constructs neutralize measles virus infection in vitro and in vivo

2021 ◽  
Author(s):  
Cyrille Mathieu ◽  
Marion Ferren ◽  
Olivia Harder ◽  
Francesca T. Bovier ◽  
Tara C. Marcink ◽  
...  
Keyword(s):  
Virus Infection ◽  
Measles Virus ◽  
Single Chain Variable Fragment ◽  
Single Chain

A Single-Chain Variable Fragment Antibody Inhibits Aggregation of Phosphorylated Tau and Ameliorates Tau Toxicity in vitro and in vivo

2021 ◽  
Vol 79 (4) ◽  
pp. 1613-1629
Author(s):  
Sen Li ◽  
Yushan Yi ◽  
Ke Cui ◽  
Yanqiu Zhang ◽  
Yange Chen ◽  
...  
Keyword(s):  
High Capacity ◽  
Scfv Antibody ◽  
Phosphorylated Tau ◽  
Single Chain Variable Fragment ◽  
Single Chain ◽  
Potential Applications ◽  
Tau Aggregation ◽  
Transgenic Drosophila

Background: Alzheimer’s disease (AD) is a common cause of dementia among elderly people. Hyperphosphorylation and aggregation of tau correlates with the clinical progression of AD; therefore, therapies targeting the aggregation of tau may have potential applications for anti-AD drug development. Several inhibitors of tau aggregation, including small molecules and antibodies, have been found to decrease the aggregation of tau and the corresponding pathology. Objective: To screen one kind of single-chain variable fragment (scFv) antibody which could inhibit the aggregation of tau and ameliorate its cytotoxicity. Methods/Results: Using phosphorylated tau (pTau) as an antigen, we obtained a scFv antibody via the screening of a high-capacity phage antibody library. Biochemical analysis revealed that this scFv antibody (scFv T1) had a strong ability to inhibit pTau aggregation both in dilute solutions and under conditions of macromolecular crowding. ScFv T1 could also depolymerize preformed pTau aggregates in vitro. Furthermore, scFv T1 was found to be able to inhibit the cytotoxicity of extracellular pTau aggregates and ameliorate tau-mediated toxicity when coexpressed with a hTauR406W mutant in the eye of transgenic Drosophila flies. Conclusion: This scFv T1 antibody may be a potential new therapeutic agent against AD. Our methods can be used to develop novel strategies against protein aggregation for the treatment of neurodegenerative diseases.

In vitro and in vivo anti-tumor activities of anti-EGFR single-chain variable fragment fused with recombinant gelonin toxin

2012 ◽  
Vol 138 (7) ◽  
pp. 1081-1090 ◽  
Author(s):  
Xikun Zhou ◽  
Ji Qiu ◽  
Zhen Wang ◽  
Nongyu Huang ◽  
Xiaolei Li ◽  
...  
Keyword(s):  
Single Chain Variable Fragment ◽  
Single Chain

Recombinant Endoglin-Single-Chain Variable Fragment/ Induced Protein 10 Fusion Protein Potently Boosts the Anti-Tumor Efficacy of Adoptively Transferred TRP2-Specific CD8+ CD28+ Cytotoxic T Lymphocytes in Mice

2020 ◽  
Vol 16 (7) ◽  
pp. 1119-1134
Author(s):  
Yangzi Li ◽  
Xiaomei Yang ◽  
Xiaoling Lu ◽  
Zhengui Peng ◽  
Chunhui Lai ◽  
...  
Keyword(s):  
T Cells ◽  
Fusion Protein ◽  
Tumor Growth ◽  
Therapeutic Efficacy ◽  
Therapeutic Potential ◽  
Suppressor Cells ◽  
Single Chain Variable Fragment ◽  
Single Chain

In this research, we studied the therapeutic efficacy of a newly designed fusion protein containing Endoglin single-chain variable fragment and IP10 (Endoglin-scFv/IP10), together with our recently generated TRP2-specific CD8+ CD28+ CTLs (CD8+ CD28+ CTLs) in controlling melanoma growth in mice. The recombinant Endoglin-scFv/IP10 was expressed in E. coli, purified by affinity chromatography, and characterized in vitro for its chemotactic movement and immunoreactivity with endoglin-expressing cells. In vivo, melanoma xenografts were established in mice (C57BL/6) using B16F10 cells. After that, mice were treated with intravenous injections of vehicle (PBS), Endoglin-scFv/IP10 alone, CD8+ CD28+ CTLs alone, or Endoglin-scFv/IP10+ CD8+ CD28+ CTLs. The therapeutic efficacy was assessed by monitoring tumor growth, mouse survival and cellular biomarkers. Endoglin-scFv/IP10 fusion protein combined with CD8+ CD28+ CTLs observed a reduction in tumor growth, resulting in improved survival. On the cellular level, the combination treatment dramatically reduced the number of systemic and tumor associated myeloid-derived suppressor cells or regulatory T cells, increased tumor-responsive interferon-γ-producing lymphocytes and tumor-associated CD8+ CXCR3+ T cells, and inhibited proliferation and angiogenesis but stimulated apoptosis within melanoma tissue. This study demonstrates the therapeutic potential of Endoglin-scFv/IP10 fusion protein in combination with CD8+ CD28+ CTLs in melanoma treatment.

TREM1/Dap12-based CAR-T cells show potent antitumor activity

Immunotherapy ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1043-1055 ◽  
Author(s):  
Bing Chen ◽  
Min Zhou ◽  
Hai Zhang ◽  
Chen Wang ◽  
Xiaocui Hu ◽  
...  
Keyword(s):  
T Cells ◽  
Antitumor Activity ◽  
Single Chain Variable Fragment ◽  
Single Chain ◽  
Car T Cells ◽  
Car T ◽  
Clinical Benefits ◽  
Chimeric Immunoreceptor

Aim: Chimeric antigen receptor-engineered T (CAR-T) cells have gained huge success in treating hematological malignancies, yet the CD3ζ-based CAR-T therapies have not shown comparable clinical benefits in solid tumors. We designed an alternative chimeric immunoreceptor in which a single-chain variable fragment was fused to the transmembrane-cytoplasmic domains of triggering receptor expressed on myeloid (TREM1), which may show potent antitumor activity. Methods: To generate TREM1/DNAX activation protein of 12 kDa (Dap12)-based CAR-T cells, TREM1 along with DAP12 was transduced into T cells. Results: TREM1/Dap12-based CAR-T cells showed more lysis in vitro and a similar antitumor effect in mouse models compared with CD19BBζ CAR-T cells. Conclusion: In this study, we designed a TREM1/Dap12-based CAR, which was not reported previously and demonstrated that TREM1/Dap12-based CAR-T cells had potent antitumor activity in vitro and in vivo.

scholarly journals Development of a bispecific immune engager using a recombinant malaria protein

2021 ◽  
Vol 12 (4) ◽  
Author(s):  
Mie A. Nordmaj ◽  
Morgan E. Roberts ◽  
Emilie S. Sachse ◽  
Robert Dagil ◽  
Anne Poder Andersen ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Immune Evasion ◽  
Blood Cells ◽  
Xenograft Model ◽  
Cancer Targeting ◽  
Single Chain Variable Fragment ◽  
Single Chain ◽  
Conjugation System ◽  
Immune Mediated

AbstractAs an immune evasion and survival strategy, the Plasmodium falciparum malaria parasite has evolved a protein named VAR2CSA. This protein mediates sequestration of infected red blood cells in the placenta through the interaction with a unique carbohydrate abundantly and exclusively present in the placenta. Cancer cells were found to share the same expression of this distinct carbohydrate, termed oncofetal chondroitin sulfate on their surface. In this study we have used a protein conjugation system to produce a bispecific immune engager, V-aCD3, based on recombinant VAR2CSA as the cancer targeting moiety and an anti-CD3 single-chain variable fragment linked to a single-chain Fc as the immune engager. Conjugation of these two proteins resulted in a single functional moiety that induced immune mediated killing of a broad range of cancer cells in vitro and facilitated tumor arrest in an orthotopic bladder cancer xenograft model.

In vitro and in vivo Sensitivity of a Non-Mouse-Adapted Influenza A (Beijing) Virus Infection to Amantadine and Ribavirin

Chemotherapy ◽  
1995 ◽  
Vol 41 (6) ◽  
pp. 455-461 ◽  
Author(s):  
Robert W. Sidwell ◽  
Kevin W. Bailey ◽  
Min Hui Wong ◽  
John H. Huffman
Keyword(s):  
Virus Infection ◽  
Influenza A

scholarly journals A Novel Bispecific Antibody Targeting EGFR and VEGFR2 Is Effective against Triple Negative Breast Cancer via Multiple Mechanisms of Action

Cancers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 1027
Author(s):  
Nishant Mohan ◽  
Xiao Luo ◽  
Yi Shen ◽  
Zachary Olson ◽  
Atul Agrawal ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Tumor Growth ◽  
Mechanisms Of Action ◽  
Breast Cancers ◽  
Single Chain ◽  
Cancer Cell Growth ◽  
Anti Tumor Activity ◽  
Enhance Tumor Growth

Both EGFR and VEGFR2 frequently overexpress in TNBC and cooperate with each other in autocrine and paracrine manner to enhance tumor growth and angiogenesis. Therapeutic mAbs targeting EGFR (cetuximab) and VEGFR2 (ramucirumab) are approved by FDA for numerous cancer indications, but none of them are approved to treat breast cancers. TNBC cells secrete VEGF-A, which mediates angiogenesis on endothelial cells in a paracrine fashion, as well as promotes cancer cell growth in autocrine manner. To disrupt autocrine/paracrine loop in TNBC models in addition to mediating anti-EGFR tumor growth signaling and anti-VEGFR2 angiogenic pathway, we generated a BsAb co-targeting EGFR and VEGFR2 (designated as anti-EGFR/VEGFR2 BsAb), using publicly available sequences in which cetuximab IgG backbone is connected to the single chain variable fragment (scFv) of ramucirumab via a glycine linker. Physiochemical characterization data shows that anti-EGFR/VEGFR2 BsAb binds to both EGFR and VEGFR2 in a similar binding affinity comparable to parental antibodies. Anti-EGFR/VEGFR2 BsAb demonstrates in vitro and in vivo anti-tumor activity in TNBC models. Mechanistically, anti-EGFR/VEGFR2 BsAb not only directly inhibits both EGFR and VEGFR2 in TNBC cells but also disrupts autocrine mechanism in TNBC xenograft mouse model. Furthermore, anti-EGFR/VEGFR2 BsAb inhibits ligand-induced activation of VEGFR2 and blocks paracrine pathway mediated by VEGF secreted from TNBC cells in endothelial cells. Collectively, our novel findings demonstrate that anti-EGFR/VEGFR2 BsAb inhibits tumor growth via multiple mechanisms of action and warrants further investigation as a targeted antibody therapeutic for the treatment of TNBC.

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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