scholarly journals Multimerization through Pegylation Improves Pharmacokinetic Properties of scFv Fragments of GD2-Specific Antibodies

Molecules ◽  
2019 ◽  
Vol 24 (21) ◽  
pp. 3835 ◽  
Author(s):  
Irina V. Kholodenko ◽  
Daniel V. Kalinovsky ◽  
Elena V. Svirshchevskaya ◽  
Igor I. Doronin ◽  
Maria V. Konovalova ◽  
...  
Keyword(s):  
Therapeutic Potential ◽  
Expression System ◽  
Cross Reactivity ◽  
Antibody Fragments ◽  
The Body ◽  
Radioactive Isotopes ◽  
Cancer Therapies ◽  
Specific Antibodies ◽  
Ganglioside Gd2 ◽  
Mammalian Expression

Antigen-binding fragments of antibodies specific to the tumor-associated ganglioside GD2 are well poised to play a substantial role in modern GD2-targeted cancer therapies, however, rapid elimination from the body and reduced affinity compared to full-length antibodies limit their therapeutic potential. In this study, scFv fragments of GD2-specific antibodies 14.18 were produced in a mammalian expression system that specifically bind to ganglioside GD2, followed by site-directed pegylation to generate mono-, di-, and tetra-scFv fragments. Fractionated pegylated dimers and tetramers of scFv fragments showed significant increase of the binding to GD2 which was not accompanied by cross-reactivity with other gangliosides. Pegylated multimeric di-scFvs and tetra-scFvs exhibited cytotoxic effects in GD2-positive tumor cells, while their circulation time in blood significantly increased compared with monomeric antibody fragments. We also demonstrated a more efficient tumor uptake of the multimers in a syngeneic GD2-positive mouse cancer model. The findings of this study provide the rationale for improving therapeutic characteristics of GD2-specific antibody fragments by multimerization and propose a strategy to generate such molecules. On the basis of multimeric antibody fragments, bispecific antibodies and conjugates with cytotoxic drugs or radioactive isotopes may be developed that will possess improved pharmacokinetic and pharmacodynamic properties.

scholarly journals A microbial expression system for high-level production of scFv HIV-neutralizing antibody fragments in Escherichia coli

2019 ◽  
Vol 103 (21-22) ◽  
pp. 8875-8888 ◽  
Author(s):  
Marloes L. C. Petrus ◽  
Lukas A. Kiefer ◽  
Pranav Puri ◽  
Evert Heemskerk ◽  
Michael S. Seaman ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Neutralizing Antibodies ◽  
Expression System ◽  
Antibody Fragment ◽  
Green Fluorescence Protein ◽  
Antibody Fragments ◽  
Single Chain ◽  
Mammalian Expression ◽  
Anti Hiv

Abstract Monoclonal antibodies (mABs) are of great biopharmaceutical importance for the diagnosis and treatment of diseases. However, their production in mammalian expression hosts usually requires extensive production times and is expensive. Escherichia coli has become a new platform for production of functional small antibody fragment variants. In this study, we have used a rhamnose-inducible expression system that allows precise control of protein expression levels. The system was first evaluated for the cytoplasmic production of super folder green fluorescence protein (sfGFP) in various production platforms and then for the periplasmic production of the anti-HIV single-chain variable antibody fragment (scFv) of PGT135. Anti-HIV broadly neutralizing antibodies, like PGT135, have potential for clinical use to prevent HIV transmission, to promote immune responses and to eradicate infected cells. Different concentrations of L-rhamnose resulted in the controlled production of both sfGFP and scFv PGT135 antibody. In addition, by optimizing the culture conditions, the amount of scFv PGT135 antibody that was expressed soluble or as inclusions bodies could be modulated. The proteins were produced in batch bioreactors, with yields of 4.9 g/L for sfGFP and 0.8 g/L for scFv. The functionality of the purified antibodies was demonstrated by their ability to neutralize a panel of different HIV variants in vitro. We expect that this expression system will prove very useful for the development of a more cost-effective production process for proteins and antibody fragments in microbial cells.

scholarly journals Evolution of Escherichia coli Expression System in Producing Antibody Recombinant Fragments

2020 ◽  
Vol 21 (17) ◽  
pp. 6324 ◽  
Author(s):  
Annamaria Sandomenico ◽  
Jwala P. Sivaccumar ◽  
Menotti Ruvo
Keyword(s):  
Expression System ◽  
Antibody Fragments ◽  
High Yield ◽  
E Coli ◽  
Mammalian Expression ◽  
Diagnostic Agents ◽  
Pros And Cons ◽  
Escherichia Coli Expression ◽  
Recombinant Fragments ◽  
Diagnostic Investigations

Antibodies and antibody-derived molecules are continuously developed as both therapeutic agents and key reagents for advanced diagnostic investigations. Their application in these fields has indeed greatly expanded the demand of these molecules and the need for their production in high yield and purity. While full-length antibodies require mammalian expression systems due to the occurrence of functionally and structurally important glycosylations, most antibody fragments and antibody-like molecules are non-glycosylated and can be more conveniently prepared in E. coli-based expression platforms. We propose here an updated survey of the most effective and appropriate methods of preparation of antibody fragments that exploit E. coli as an expression background and review the pros and cons of the different platforms available today. Around 250 references accompany and complete the review together with some lists of the most important new antibody-like molecules that are on the market or are being developed as new biotherapeutics or diagnostic agents.

Integrating Focusing and Differentiation: A Therapeutic Path for Couples in Intimate Relationships

2018 ◽  
Vol 3 ◽  
Author(s):  
Evi Zohar
Keyword(s):  
Couples Therapy ◽  
Therapeutic Potential ◽  
Well Being ◽  
Point Of View ◽  
The Body ◽  
Self Awareness ◽  
Emotional Healing ◽  
Felt Sense ◽  
Inner World

Continuing the workshop I've given in the WPC Paris (2017), this article elaborates my discussion of the way I interlace Focusing with Differentiation Based Couples Therapy (Megged, 2017) under the systemic view, in order to facilitate processes of change and healing in working with intimate couples. This article presents the theory and rationale of integrating Differentiation (Bowen, 1978; Schnarch, 2009; Megged, 2017) and Focusing (Gendlin, 1981) approaches, and its therapeutic potential in couple's therapy. It is written from the point of view of a practicing professional in order to illustrate the experiential nature and dynamics of the suggested therapeutic path. Differentiation is a key to mutuality. It offers a solution to the central struggle of any long term intimate relationship: balancing two basic life forces - the drive for individuality and the drive for togetherness (Schnarch, 2009). Focusing is a body-oriented process of self-awareness and emotional healing, in which one learns to pay attention to the body and the ‘Felt Sense’, in order to unfold the implicit, keep it in motion at the precise pace it needs for carrying the next step forward (Gendlin, 1996). Combining Focusing and Differentiation perspectives can cultivate the kind of relationship where a conflict can be constructively and successfully held in the inner world of each partner, while taking into consideration the others' well-being. This creates the possibility for two people to build a mutual emotional field, open to changes, permeable and resilient.

Therapeutic Potential of Agonists and Antagonists of A1, A2a, A2b and A3 Adenosine Receptors

2019 ◽  
Vol 25 (26) ◽  
pp. 2892-2905 ◽  
Author(s):  
Sumit Jamwal ◽  
Ashish Mittal ◽  
Puneet Kumar ◽  
Dana M. Alhayani ◽  
Amal Al-Aboudi
Keyword(s):  
Nervous System ◽  
Therapeutic Potential ◽  
The Body ◽  
Membrane Receptors ◽  
Physiological Importance ◽  
Physiological Processes ◽  
Central Nervous Systems ◽  
Energy Consuming ◽  
Metabolic Dysfunctions ◽  
G Protein Coupled

Adenosine is a naturally occurring nucleoside and an essential component of the energy production and utilization systems of the body. Adenosine is formed by the degradation of adenosine-triphosphate (ATP) during energy-consuming processes. Adenosine regulates numerous physiological processes through activation of four subtypes of G-protein coupled membrane receptors viz. A1, A2A, A2B and A3. Its physiological importance depends on the affinity of these receptors and the extracellular concentrations reached. ATP acts as a neurotransmitter in both peripheral and central nervous systems. In the peripheral nervous system, ATP is involved in chemical transmission in sensory and autonomic ganglia, whereas in central nervous system, ATP, released from synaptic terminals, induces fast excitatory postsynaptic currents. ATP provides the energetics for all muscle movements, heart beats, nerve signals and chemical reactions inside the body. Adenosine has been traditionally considered an inhibitor of neuronal activity and a regulator of cerebral blood flow. Since adenosine is neuroprotective against excitotoxic and metabolic dysfunctions observed in neurological and ocular diseases, the search for adenosinerelated drugs regulating adenosine transporters and receptors can be important for advancement of therapeutic strategies against these diseases. This review will summarize the therapeutic potential and recent SAR and pharmacology of adenosine and its receptor agonists and antagonists.

Breast Cancer Resistance Protein: A Potential Therapeutic Target for Cancer

2020 ◽  
Vol 21 ◽  
Author(s):  
Sonali Mehendale-Munj
Keyword(s):  
Breast Cancer ◽  
Breast Cancer Resistance Protein ◽  
Protein A ◽  
The Body ◽  
Cancer Therapies ◽  
Cancer Resistance ◽  
Lung Cancers ◽  
Resistance Protein ◽  
Atp Regulation ◽  
Treatment Procedures

: Breast Cancer Resistance Protein (BCRP) is an efflux transporter responsible for causing multidrug re-sistance(MDR). It is known to expel many potent antineoplastic drugs, owing to its efflux function. Efflux of chemothera-peutics because of BCRP develops resistance to manydrugs, leading to failure in cancer treatment. BCRP plays an important role in physiology by protecting the organism from xenobiotics and other toxins. It is a half-transporter affiliated to theATP-binding cassette (ABC) superfamily of transporters, encoded by the gene ABCG2 and functions in response to adenosine triphosphate (ATP). Regulation of BCRP expression is critically controlled at molecular levels which help in maintaining the balance of xenobiotics and nutrients inside the body. Expression of BCRP can be found in brain, liver, lung cancers and acute myeloid leukemia (AML). Moreover, it is also expressed at high levels in stem cells and many cell lines. This frequent expression of BCRP has an impact on the treatment procedures and if not scrutinized may lead to failure of many cancer therapies.

scholarly journals Severe Fever with Thrombocytopenia Syndrome in Cats and Its Prevalence among Veterinarian Staff Members in Nagasaki, Japan

Viruses ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1142
Author(s):  
Tsuyoshi Ando ◽  
Takeshi Nabeshima ◽  
Shingo Inoue ◽  
Mya Myat Ngwe Tun ◽  
Miho Obata ◽  
...  
Keyword(s):  
Cell Cultures ◽  
Phylogenetic Analyses ◽  
The Body ◽  
Virus Growth ◽  
Specific Antibodies ◽  
Staff Members ◽  
Zoonotic Risk ◽  
Sentinel Animals ◽  
Animal Care ◽  
Severe Fever

In this study, we investigated severe fever with thrombocytopenia syndrome (SFTS) virus (SFTSV) infection in cats in Nagasaki, Japan. In total, 44 of 133 (33.1%) cats with suspected SFTS were confirmed to be infected with SFTSV. Phylogenetic analyses of SFTSV isolates from cats indicated that the main genotype in Nagasaki was J1 and that unique reassortant strains with J2 (S segment) and unclassified genotypes (M and L segments) were also present. There were no significant differences in virus growth in cell cultures or fatality in SFTSV-infected mice between the SFTSV strains that were isolated from recovered and fatal cat cases. Remarkably, SFTSV RNAs were detected in the swabs from cats, indicating that the body fluids contain SFTSV. To evaluate the risk of SFTSV infection when providing animal care, we further examined the seroprevalence of SFTSV infection in veterinarian staff members; 3 of 71 (4.2%) were seropositive for SFTSV-specific antibodies. Our results provide useful information on the possibility of using cats as sentinel animals and raised concerns of the zoonotic risk of catching SFTSV from animals.

scholarly journals Dietary Curcumin: Correlation between Bioavailability and Health Potential

Nutrients ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 2147 ◽  
Author(s):  
Michele Dei Cas ◽  
Riccardo Ghidoni
Keyword(s):  
Small Intestine ◽  
Cellular Uptake ◽  
Oral Delivery ◽  
Therapeutic Potential ◽  
Pharmacokinetic Profile ◽  
Yellow Pigment ◽  
The Body ◽  
Anti Cancer ◽  
Poor Absorption ◽  
Oral Delivery Systems

The yellow pigment curcumin, extracted from turmeric, is a renowned polyphenol with a broad spectrum of health properties such as antioxidant, anti-inflammatory, anti-cancer, antidiabetic, hepatoprotective, anti-allergic, anti-dermatophyte, and neuroprotective. However, these properties are followed by a poor pharmacokinetic profile which compromises its therapeutic potential. The association of low absorption by the small intestine and the extensive reductive and conjugative metabolism in the liver dramatically weakens the oral bioavailability. Several strategies such as inhibition of curcumin metabolism with adjuvants as well as novel solid and liquid oral delivery systems have been tried to counteract curcumin poor absorption and rapid elimination from the body. Some of these drug deliveries can successfully enhance the solubility, extending the residence in plasma, improving the pharmacokinetic profile and the cellular uptake.

scholarly journals A High-Performance Multiplex Immunoassay for Serodiagnosis of Flavivirus-Associated Neurological Diseases in Horses

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Cécile Beck ◽  
Philippe Desprès ◽  
Sylvie Paulous ◽  
Jessica Vanhomwegen ◽  
Steeve Lowenski ◽  
...  
Keyword(s):  
High Performance ◽  
Neurological Diseases ◽  
Expression System ◽  
Cross Reactivity ◽  
Encephalitis Virus ◽  
Serological Tests ◽  
Multiplex Immunoassay ◽  
Tick Borne Encephalitis ◽  
Tick Borne Encephalitis Virus ◽  
Negative Controls

West Nile virus (WNV), Japanese encephalitis virus (JEV), and tick-borne encephalitis virus (TBEV) are flaviviruses responsible for severe neuroinvasive infections in humans and horses. The confirmation of flavivirus infections is mostly based on rapid serological tests such as enzyme-linked immunosorbent assays (ELISAs). These tests suffer from poor specificity, mainly due to antigenic cross-reactivity among flavivirus members. Robust diagnosis therefore needs to be validated through virus neutralisation tests (VNTs) which are time-consuming and require BSL3 facilities. The flavivirus envelope (E) glycoprotein ectodomain is composed of three domains (D) named DI, DII, and DIII, with EDIII containing virus-specific epitopes. In order to improve the serological differentiation of flavivirus infections, the recombinant soluble ectodomain of WNV E (WNV.sE) and EDIIIs (rEDIIIs) of WNV, JEV, and TBEV were synthesised using theDrosophilaS2 expression system. Purified antigens were covalently bonded to fluorescent beads. The microspheres coupled to WNV.sE or rEDIIIs were assayed with about 300 equine immune sera from natural and experimental flavivirus infections and 172 nonimmune equine sera as negative controls. rEDIII-coupled microspheres captured specific antibodies against WNV, TBEV, or JEV in positive horse sera. This innovative multiplex immunoassay is a powerful alternative to ELISAs and VNTs for veterinary diagnosis of flavivirus-related diseases.

RADIOIMMUNOASSAY FOR 2-METHOXYOESTRONE IN HUMAN PLASMA

1979 ◽  
Vol 91 (1) ◽  
pp. 158-166 ◽  
Author(s):  
Günter Emons ◽  
Peter Ball ◽  
Gertrud v. Postel ◽  
Rudolf Knuppen
Keyword(s):  
Human Plasma ◽  
Plasma Concentrations ◽  
Cross Reactivity ◽  
Elderly Men ◽  
Specific Antibodies ◽  
Assay Procedure ◽  
Menopausal Women ◽  
Bovine Serum Albumin Conjugate ◽  
Post Menopausal

ABSTRACT A bovine serum albumin conjugate of 2-methoxyoestrone was used for the preparation of highly specific antibodies in rabbits. Cross-reactivity for catecholoestrogens and monophenolic steroids was below 0.3 %. Only 2-methoxyoestradiol cross-reacted with 44 %. An assay procedure for the determination of unconjugated and conjugated 2-methoxyoestrone in human plasma is described. The following mean plasma concentrations (pg/ml) were found (unconjugated/conjugated): children 61/1130, young men 74/1320, elderly men 109/1260, cycling women 131/1040, post-menopausal women 102/1420, and pregnant women 3980/5850.

Latent TGF-beta binding protein LTBP-1 contains three potential extracellular matrix interacting domains

2001 ◽  
Vol 114 (1) ◽  
pp. 187-197 ◽  
Author(s):  
C. Unsold ◽  
M. Hyytiainen ◽  
L. Bruckner-Tuderman ◽  
J. Keski-Oja
Keyword(s):  
Extracellular Matrix ◽  
Expression System ◽  
Covalent Binding ◽  
Sodium Deoxycholate ◽  
Current Data ◽  
Lung Fibroblasts ◽  
Tgf Beta ◽  
Mammalian Expression ◽  
The Matrix ◽  
Recombinant Fragments

Latent TGF-beta binding proteins (LTBPs) are components of the extracellular matrix (ECM). They belong to the fibrillin/LTBP-superfamily, and are high molecular weight glycoproteins characterized by EGF-like repeats and 8-Cys repeats. Most LTBPs associate with the small latent forms of TGF-beta. Their roles include to facilitate the secretion of latent TGF-beta and to target it to the ECM. In order to identify new matrix-binding domains of LTBP-1 and to characterize their association with the extracellular matrix, we have produced (in a mammalian expression system) partly overlapping recombinant fragments of its shorter form, LTBP-1S, and analyzed the binding of the purified fusion proteins to extracellular matrices of cultured human dermal and lung fibroblasts. Recombinant fragments from three different regions of the N- and C-termini showed affinity to the matrix. These interacting regions contain either the first (hybrid), second or fourth 8-Cys domains of the LTBP-1S molecule. They bound independently to the matrix. Each of them had an ability to inhibit the association of native exogenous LTBP-1 with fibroblast extracellular matrix. The interactions of the LTBP-1 fragments with the extracellular matrix resisted treatment with sodium deoxycholate, suggesting strong, possibly covalent binding. The binding occurred in a time- and dose-dependent fashion. The N-terminal fragments bound more readily to the matrices. With all fragments the binding took place both with intact fibroblast matrices and with matrices isolated by sodium deoxycholate. When using CHO cell layers, which form sparse matrices, only the N-terminal fragment of LTBP-1 was efficiently incorporated. The association of the binding fragments with isolated matrices was enhanced by soluble, cell-derived factors. The current data suggest that LTBP-1 contains three different domains with an ability to associate with the extracellular matrix.

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