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Antibody engineering

Sunandan Mukherjee, Chandran Nithin, Yasaswi Divakaruni, Ranjit Prasad Bahadur
We dissect the protein-protein interfaces into water preservation (WP), water hydration (WH) and water dehydration (WD) sites by comparing the water mediated hydrogen bonds (H-bond) in the bound and unbound states of the interacting subunits. Upon subunit complexation, if a H-bond between an interface water and a protein polar group is retained, we assign it as WP site; if it is lost, we assign it as WD site and if a new H-bond is created, we assign it as WH site. We find that the density of WD sites is highest followed by WH and WP sites except in antigen and (or) antibody complexes, where the density of WH sites is highest followed by WD and WP sites...
March 16, 2018: Journal of Biomolecular Structure & Dynamics
Fernanda Ramos-Gomes, Julia Bode, Alyona Sukhanova, Svetlana V Bozrova, Mara Saccomano, Miso Mitkovski, Julia Eva Krueger, Anja K Wege, Walter Stuehmer, Pavel S Samokhvalov, Daniel Baty, Patrick Chames, Igor Nabiev, Frauke Alves
Early detection of malignant tumours and, especially, micrometastases and disseminated tumour cells is still a challenge. In order to implement highly sensitive diagnostic tools we demonstrate the use of nanoprobes engineered from nanobodies (single-domain antibodies, sdAbs) and fluorescent quantum dots (QDs) for single- and two-photon detection and imaging of human micrometastases and disseminated tumour cells in ex vivo biological samples of breast and pancreatic metastatic tumour mouse models expressing human epidermal growth factor receptor 2 (HER2) or carcinoembryonic antigen (CEA)...
March 15, 2018: Scientific Reports
Aaron Hubbard, Thomas Reodl, Ada Hui, Stephanie Knueppel, Kirk Eppler, Siegfried Lehnert, Yuh-Fun Maa
A monoclonal antibody drug product (DP) manufacturing process was transferred to a different production site, where aseptic filling took place within an isolator that was sanitized using vapor phase hydrogen peroxide (VPHP). A quality-by-design approach was applied for study design to understand the impact of VPHP uptake in the isolator on DP quality. A combination of small-scale and manufacturing-scale studies was performed to evaluate the sensitivity of the monoclonal antibody to hydrogen peroxide (H2O2) as well as VPHP uptake mechanisms during the filling process...
March 15, 2018: PDA Journal of Pharmaceutical Science and Technology
Hamid Reza Mirzaei, Hossein Pourghadamyari, Majid Rahmati, Abbas Mohammadi, Javid Sadri Nahand, Abbas Rezaei, Hamed Mirzaei, Jamshid Hadjati
Recently clinical trials utilizing genetically engineered T cells expressing a chimeric antigen receptor (CAR) that is half monoclonal antibody and half T-cell receptor have demonstrated remarkable response in patients with advanced cancers like relapsed or refractory acute lymphoblastic leukemia (ALL) and lymphoma. Moreover, emerging chimeric genome editing tools such as zinc-finger nucleases (ZNFs), transcription activator-like effector nucleases (TALENs) and clustered regulatory interspaced short palindromic repeat (CRISPR)/Cas composed of sequence-specific DNA binding module(s) linked to a non-specific DNA cleavage domain have made possible to dramatically expand the ability to manipulate cells aim to treat and/or study a wide range of diseases including cancer...
March 12, 2018: Cancer Letters
Dongfen Yuan, Frederik Rode, Yanguang Cao
We proposed here a minimal physiologically based pharmacokinetic (mPBPK) model for a group of novel engineered antibodies in mice and humans. These antibodies are designed with altered binding properties of their Fc domain with neonatal Fc receptor (FcRn) or the Fab domain with their cognate targets (recycling antibodies) in acidic endosomes. To enable simulations of such binding features in the change of antibody pharmacokinetics and its target suppression, we nested an endothelial endosome compartment in parallel with plasma compartment based on our previously established mPBPK model...
March 14, 2018: AAPS Journal
Katherine D Hills, Daniela A Oliveira, Nicholas D Cavallaro, Carmen L Gomes, Eric S McLamore
We demonstrate a sensing mechanism for rapid detection of Listeria monocytogenes in food samples using the actuation of chitosan-aptamer nanobrush borders. The bio-inspired soft material and sensing strategy mimic natural symbiotic systems, where low levels of bacteria are selectively captured from complex matrices. To engineer this biomimetic system, we first develop reduced graphene oxide/nanoplatinum (rGO-nPt) electrodes, and characterize the fundamental electrochemical behavior in the presence and absence of chitosan nanobrushes during actuation (pH-stimulated osmotic swelling)...
March 15, 2018: Analyst
Taigo Kato, Tatsuo Matsuda, Yuji Ikeda, Jae-Hyun Park, Matthias Leisegang, Sachiko Yoshimura, Tetsuro Hikichi, Makiko Harada, Makda Zewde, Sho Sato, Kosei Hasegawa, Kazuma Kiyotani, Yusuke Nakamura
Neoantigens are the main targets of tumor-specific T cells reactivated by immune checkpoint-blocking antibodies or when using tumor-infiltrating T cells for adoptive therapy. While cancers often accumulate hundreds of mutations and harbor several immunogenic neoantigens, the repertoire of mutation-specific T cells in patients might be restricted. To bypass suboptimal conditions, which impede the reactivation of existing T cells or the priming of neoantigen-specific T cells in a patient, we employ T cells of healthy donors with an overlapping HLA repertoire to target cancer neoantigens...
February 16, 2018: Oncotarget
Liaoran Wang, David K C Cooper, Lars Burdorf, Yi Wang, Hayato Iwase
There has recently been considerable progress in the results of pig organ transplantation in nonhuman primates (NHPs), largely associated with the availability of (i) pigs genetically-engineered to overcome coagulation dysregulation, and (ii) novel immunosuppressive agents. The barriers of thrombotic microangiopathy and/or consumptive coagulation were believed to be associated with (i) activation of the graft vascular endothelial cells (VECs) by a low level of anti-pig antibody binding and/or complement deposition and/or innate immune cell activity, and (ii) molecular incompatibilities between the NHP and pig coagulation-anticoagulation systems...
March 10, 2018: Transplantation
Jonas V Schaefer, Erik Sedlák, Florian Kast, Michal Nemergut, Andreas Plückthun
Biophysical properties of antibody-based biopharmaceuticals are a critical part of their release criteria. In this context, finding the appropriate formulation is equally important as optimizing their intrinsic biophysical properties through protein engineering, and both are mutually dependent. Most previous studies have empirically tested the impact of additives on measures of colloidal stability, while mechanistic aspects have usually been limited to only the thermodynamic stability of the protein. Here we emphasize the kinetic impact of additives on the irreversible denaturation steps of immunoglobulins G (IgG) and their antigen-binding fragments (Fabs), as these are the key committed steps preceding aggregation, and thus especially informative in elucidating the molecular parameters of activity loss...
March 14, 2018: MAbs
Wen-Ting K Tsai, Anna M Wu
The exquisite specificity of antibodies and antibody fragments renders them excellent agents for targeted delivery of radionuclides. Radiolabeled antibodies and fragments have been successfully used for molecular imaging and radioimmunotherapy (RIT) of cell-surface targets in oncology and immunology. Protein engineering has been employed for antibody humanization essential for clinical applications, as well as optimization of important characteristics including pharmacokinetics, biodistribution, and clearance...
March 14, 2018: Journal of Labelled Compounds & Radiopharmaceuticals
Roland B Walter
There is long-standing interest in drugs targeting the myeloid differentiation antigen CD33 in acute myeloid leukemia (AML). Positive results from randomized trials with the antibody-drug conjugate (ADC) gemtuzumab ozogamicin (GO) validate this approach. Partly stimulated by the success of GO, several CD33-targeted therapeutics are currently in early phase testing. Areas covered: CD33-targeted therapeutics in clinical development include Fc-engineered unconjugated antibodies (BI 836858 [mAb 33.1]), ADCs (SGN-CD33A [vadastuximab talirine], IMGN779), radioimmunoconjugates (225 Ac-lintuzumab), bi- and trispecific antibodies (AMG 330, AMG 673, AMV564, 161533 TriKE fusion protein), and chimeric antigen receptor (CAR)-modified immune effector cells...
March 15, 2018: Expert Opinion on Investigational Drugs
Richard J Zahrl, Diethard Mattanovich, Brigitte Gasser
The yeast Pichia pastoris (syn. Komagataella spp.) is a popular cell factory for recombinant protein production. Yeasts in general provide a good starting point for cell factory engineering. They are intrinsically robust and easy to manipulate and cultivate. However, their secretory pathway is not evolutionarily adapted to high loads of secretory protein. In particular, more complex proteins, like the antibody fragment (Fab) used in this study, overwhelm the folding and secretion capacity. This triggers cellular stress responses, which may cause excessive intracellular degradation...
March 13, 2018: Microbiology
Y S Tan, K Sansanaphongpricha, M E P Prince, D Sun, G T Wolf, Y L Lei
The recent Food and Drug Administration's approval of monoclonal antibodies targeting immune checkpoint receptors (ICRs) for recurrent or metastatic head and neck squamous cell carcinoma (HNSCC) offers exciting promise to improve patient outcome and reduce morbidities. A favorable response to ICR blockade relies on an extensive collection of preexisting tumor-specific T cells in the tumor microenvironment (TME). ICR blockade reinvigorates exhausted CD8+ T cells and enhances immune killing. However, resistance to ICR blockade is observed in about 85% of patients with HNSCC, therefore highlighting the importance of characterizing the mechanisms underlying HNSCC immune escape and exploring combinatorial strategies to sensitize hypoimmunogenic cold HNSCC to ICR inhibition...
March 1, 2018: Journal of Dental Research
Kelley M Heffner, Qiong Wang, Deniz Baycin Hizal, Özge Can, Michael J Betenbaugh
Mammalian expression systems such as Chinese hamster ovary (CHO), mouse myeloma (NS0), and human embryonic kidney (HEK) cells serve a critical role in the biotechnology industry as the production host of choice for recombinant protein therapeutics. Most of the recombinant biologics are glycoproteins that contain complex oligosaccharide or glycan attachments representing a principal component of product quality. Both N-glycans and O-glycans are present in these mammalian cells, but the engineering of N-linked glycosylation is of critical interest in industry and many efforts have been directed to improve this pathway...
March 13, 2018: Advances in Biochemical Engineering/biotechnology
Yan Weng, Tetsuya Ishino, Annette Sievers, Saswata Talukdar, Jeffrey R Chabot, Amy Tam, Weili Duan, Kelvin Kerns, Eric Sousa, Tao He, Alison Logan, Darwin Lee, Dongmei Li, Yingjiang Zhou, Barbara Bernardo, Alison Joyce, Mania Kavosi, Denise M O'Hara, Tracey Clark, Jie Guo, Craig Giragossian, Mark Stahl, Roberto A Calle, Ron Kriz, Will Somers, Laura Lin
Pharmacological administration of FGF21 analogues has shown robust body weight reduction and lipid profile improvement in both dysmetabolic animal models and metabolic disease patients. Here we report the design, optimization, and characterization of a long acting glyco-variant of FGF21. Using a combination of N-glycan engineering for enhanced protease resistance and improved solubility, Fc fusion for further half-life extension, and a single point mutation for improving manufacturability in Chinese Hamster Ovary cells, we created a novel FGF21 analogue, Fc-FGF21[R19V][N171] or PF-06645849, with substantially improved solubility and stability profile that is compatible with subcutaneous (SC) administration...
March 9, 2018: Scientific Reports
Matic Grom, Mirijam Kozorog, Simon Caserman, Andrej Pohar, Blaž Likozar
Protein A-based affinity chromatography is a highly-efficient separation method to capture, purify and isolate biosimilar monoclonal antibodies (mAb) - an important medical product of biopharmaceutical industrial manufacturing. It is considered the most expensive step in purification downstream operations; therefore, its performance optimization offers a great cost saving in the overall production expenditure. The biochemical mixture-separating specific interaction experiments with Chinese hamster ovary (CHO) cell culture harvest, containing glycosylated extracellular immunoglobulins (Ig), were made using five different state-of-the-art commercial resins...
March 1, 2018: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
Felix A Rey, Shee-Mei Lok
Enveloped viruses enter cells by inducing fusion of viral and cellular membranes, a process catalyzed by a specialized membrane-fusion protein expressed on their surface. This review focuses on recent structural studies of viral fusion proteins with an emphasis on their metastable prefusion form and on interactions with neutralizing antibodies. The fusion glycoproteins have been difficult to study because they are present in a labile, metastable form at the surface of infectious virions. Such metastability is a functional requirement, allowing these proteins to refold into a lower energy conformation while transferring the difference in energy to catalyze the membrane fusion reaction...
March 8, 2018: Cell
María Elena Iezzi, Lucía Policastro, Santiago Werbajh, Osvaldo Podhajcer, Gabriela Alicia Canziani
Monoclonal antibodies and their fragments have significantly changed the outcome of cancer in the clinic, effectively inhibiting tumor cell proliferation, triggering antibody-dependent immune effector cell activation and complement mediated cell death. Along with a continued expansion in number, diversity, and complexity of validated tumor targets there is an increasing focus on engineering recombinant antibody fragments for lead development. Single-domain antibodies (sdAbs), in particular those engineered from the variable heavy-chain fragment (VHH gene) found in Camelidae heavy-chain antibodies (or IgG2 and IgG3), are the smallest fragments that retain the full antigen-binding capacity of the antibody with advantageous properties as drugs...
2018: Frontiers in Immunology
Anne Leferink, Diogo Santos, Clemens A van Blitterswijk, Lorenzo Moroni
When tissue engineering strategies rely on the combination of three-dimensional (3D) polymeric or ceramic scaffolds with cells to culture implantable tissue construct in vitro, it is desirable to monitor tissue growth and cell fate to be able to more rationally predict the quality and success of the construct upon implantation. Such a 3D construct is often referred to as a 'black-box' since the properties of the scaffolds material limit the applicability of most imaging modalities to assess important construct parameters...
March 8, 2018: Biomedical Materials
Bhavani Gopalakrishnan, Carolyn Cheney, Rajeswaran Mani, Xiaokui Mo, Donna Bucci, Alison Walker, Rebecca Klisovic, Bhavana Bhatnagar, Katherine Walsh, Bjoern Rueter, Irene C Waizenegger, Karl-Heinz Heider, William Blum, Sumithira Vasu, Natarajan Muthusamy
Acute myeloid leukemia (AML) is the second most common type of leukemia in adults. Incidence of AML increases with age with a peak incidence at 67 years. Patients older than 60 years have an unfavorable prognosis due to resistance to conventional chemotherapy. Volasertib (BI 6727) is a cell-cycle regulator targeting polo-like kinase which has been evaluated in clinical trials in AML. We evaluated effects of volasertib in primary patient samples and NK cells. At equivalent doses, volasertib is cytotoxic to AML blasts but largely spares healthy NK cells...
February 9, 2018: Oncotarget
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