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 ◽  
...  

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.

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

Author(s):  
Cyrille Mathieu ◽  
Marion Ferren ◽  
Olivia Harder ◽  
Francesca T. Bovier ◽  
Tara C. Marcink ◽  
...  

2020 ◽  
Vol 16 (7) ◽  
pp. 1119-1134
Author(s):  
Yangzi Li ◽  
Xiaomei Yang ◽  
Xiaoling Lu ◽  
Zhengui Peng ◽  
Chunhui Lai ◽  
...  

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.


Immunotherapy ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1043-1055 ◽  
Author(s):  
Bing Chen ◽  
Min Zhou ◽  
Hai Zhang ◽  
Chen Wang ◽  
Xiaocui Hu ◽  
...  

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.


2021 ◽  
Author(s):  
Anthony Aggidis ◽  
Shreyasi Chatterjee ◽  
David Townsend ◽  
Nigel J Fullwood ◽  
Eva Ruiz Ortega ◽  
...  

There are currently no disease altering drugs available for Tauopathies such as Alzheimer's disease, which alone is predicted to affect ~88 million people worldwide by 2050. As Tau aggregation underpins its toxicity, aggregation inhibitors are likely to have disease-modifying potential. Guided by in-silico mutagenesis studies, we developed a potent retro-inverso peptide inhibitor of Tau aggregation, RI-AG03 [AcrrrrrrrrGpkyk( ac)iqvGr-NH2], based on the 306VQIVYK311 hotspot. Aggregation of recombinant Tau was reduced by >90% with equimolar RI-AG03 and no fibrils were observed by EM. When added during the growth phase, RI-AG03 blocked seeded aggregation. Fluorescein-tagged RI-AG03 efficiently penetrated HEK-293 cells over 24 hours and was non-toxic at doses up to 30 μM. In transgenic Drosophila, RI-AG03 significantly improves neurodegenerative and behavioural phenotypes caused by expression of human Tau. Collectively this shows that RI-AG03 can effectively reduce Tau aggregation in vitro and block aggregationdependent phenotypes in vivo, raising possibilities for exploring its translational potential.


2021 ◽  
Vol 22 (15) ◽  
pp. 8106
Author(s):  
Tianming Song ◽  
Yawei Qu ◽  
Zhe Ren ◽  
Shuang Yu ◽  
Mingjian Sun ◽  
...  

Despite the numerous available treatments for cancer, many patients succumb to side effects and reoccurrence. Zinc oxide (ZnO) quantum dots (QDs) are inexpensive inorganic nanomaterials with potential applications in photodynamic therapy. To verify the photoluminescence of ZnO QDs and determine their inhibitory effect on tumors, we synthesized and characterized ZnO QDs modified with polyvinylpyrrolidone. The photoluminescent properties and reactive oxygen species levels of these ZnO/PVP QDs were also measured. Finally, in vitro and in vivo experiments were performed to test their photodynamic therapeutic effects in SW480 cancer cells and female nude mice. Our results indicate that the ZnO QDs had good photoluminescence and exerted an obvious inhibitory effect on SW480 tumor cells. These findings illustrate the potential applications of ZnO QDs in the fields of photoluminescence and photodynamic therapy.


2021 ◽  
Vol 12 (4) ◽  
Author(s):  
Mie A. Nordmaj ◽  
Morgan E. Roberts ◽  
Emilie S. Sachse ◽  
Robert Dagil ◽  
Anne Poder Andersen ◽  
...  

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.


2020 ◽  
Vol 7 (2) ◽  
pp. 36 ◽  
Author(s):  
João P. Cotovio ◽  
Tiago G. Fernandes

Liver disease is one of the leading causes of death worldwide, leading to the death of approximately 2 million people per year. Current therapies include orthotopic liver transplantation, however, donor organ shortage remains a great challenge. In addition, the development of novel therapeutics has been limited due to the lack of in vitro models that mimic in vivo liver physiology. Accordingly, hepatic cell lineages derived from human pluripotent stem cells (hPSCs) represent a promising cell source for liver cell therapy, disease modelling, and drug discovery. Moreover, the development of new culture systems bringing together the multiple liver-specific hepatic cell types triggered the development of hPSC-derived liver organoids. Therefore, these human liver-based platforms hold great potential for clinical applications. In this review, the production of the different hepatic cell lineages from hPSCs, including hepatocytes, as well as the emerging strategies to generate hPSC-derived liver organoids will be assessed, while current biomedical applications will be highlighted.


Parasitology ◽  
2006 ◽  
Vol 133 (3) ◽  
pp. 261-278 ◽  
Author(s):  
A. HEMPHILL ◽  
N. VONLAUFEN ◽  
A. NAGULESWARAN

Neospora caninumis an apicomplexan parasite that is closely related toToxoplasma gondii, the causative agent of toxoplasmosis in humans and domestic animals. However, in contrast toT. gondii, N. caninumrepresents a major cause of abortion in cattle, pointing towards distinct differences in the biology of these two species. There are 3 distinct key features that represent potential targets for prevention of infection or intervention against disease caused byN. caninum. Firstly, tachyzoites are capable of infecting a large variety of host cellsin vitroandin vivo. Secondly, the parasite exploits its ability to respond to alterations in living conditions by converting into another stage (tachyzoite-to-bradyzoite orvice versa). Thirdly, by analogy withT. gondii, this parasite has evolved mechanisms that modulate its host cells according to its own requirements, and these must, especially in the case of the bradyzoite stage, involve mechanisms that ensure long-term survival of not only the parasite but also of the host cell. In order to elucidate the molecular and cellular bases of these important features ofN. caninum, cell culture-based approaches and laboratory animal models are being exploited. In this review, we will summarize the current achievements related to host cell and parasite cell biology, and will discuss potential applications for prevention of infection and/or disease by reviewing corresponding work performed in murine laboratory infection models and in cattle.


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