Production of monoclonal antibodies for therapeutic purposes: A review

High-throughput single-cell analysis reveals Omp38-specific monoclonal antibodies that protect against Acinetobacter baumannii infection

Infections caused by Acinetobacter baumannii (A. baumannii) have emerged as a global public health concern because of high pathogenicity of this bacterium. Monoclonal antibodies (mAbs) have a lower likelihood of promoting drug resistance and offer targeted treatment, thereby reducing potential adverse effects; however, the therapeutic potential of mAbs targeting A. baumannii has not been fully characterized. In this study, mAbs against the outer membrane proteins (OMPs) of A. baumannii were isolated in a high-throughput manner. The ability of Omp38-specific mAbs to bind to A. baumannii strains from diverse sources was confirmed via enzyme-linked immunosorbent assay (ELISA). Intravenous administration of the Omp38-specific mAbs significantly improved the survival rate and reduced the bacterial load in a mouse model of lethal A. baumannii infection. Flow cytometry and ELISA confirmed that immune cell infiltration and cytokine production, respectively, decreased in a mouse model of sublethal A. baumannii infection. In addition, analysis of the Omp38-mAb C3 binding conformation revealed the potential mechanism of broad-spectrum binding activity of this mAb against A. baumannii. Taken together, these findings indicate that mAbs against Omp38 facilitate bacterial clearance from host, minimize inflammatory mediator release and reduce host damage, highlighting the potential of Omp38-specific mAbs in the clinical treatment of A. baumannii infection.

Challenges and opportunities in single-domain antibody-based tumor immunotherapy

Single-domain antibodies (sdAbs) have emerged as a promising tool in tumor immunotherapy, garnering significant attention in recent years due to their unique structure and superior properties. Unlike traditional antibodies, sdAbs exhibit several advantages, including small molecular weight, high stability, strong affinity, and high specificity. These characteristics enable sdAbs to effectively target and eliminate tumor cells within the complex tumor microenvironment. Moreover, their structural advantages enhance tissue penetration and reduce immunogenicity, thereby increasing their potential for clinical application. The potential applications of sdAbs include novel immune checkpoint inhibitors, bispecific antibody drugs, innovative immune cell therapies, antibody-drug conjugate therapies, and tumor molecular imaging diagnostics. Despite the promising prospects, several challenges of sdAb-based tumor immunotherapy still require further investigation. This review aims to summarize the status of sdAb-based immunotherapy, identify the challenges encountered, and evaluate the clinical research and application potential of sdAbs in this field.

Clonally expanded, targetable, natural killer-like NKG7 T cells seed the aged spinal cord to disrupt myeloid-dependent wound healing

Spinal cord injury (SCI) increasingly affects aged individuals, where functional impairment and mortality are highest. However, the aging-dependent mechanisms underpinning tissue damage remain elusive. Here, we find that natural killer-like T (NKLT) cells seed the intact aged human and murine spinal cord and multiply further after injury. NKLT cells accumulate in the spinal cord via C-X-C motif chemokine receptor 6 and ligand 16 signaling to clonally expand by engaging with major histocompatibility complex (MHC)-I-expressing myeloid cells. NKLT cells expressing natural killer cell granule protein 7 (Nkg7) disrupt myeloid-cell-dependent wound healing in the aged injured cord. Nkg7 deletion in mice curbs NKLT cell degranulation to normalize the myeloid cell phenotype, thus promoting tissue repair and axonal integrity. Monoclonal antibodies neutralizing CD8+ T cells after SCI enhance neurological recovery by promoting wound healing. Our results unveil a reversible role for NKG7+CD8+ NKLT cells in exacerbating tissue damage, suggesting a clinically relevant treatment for SCI.

Hyphenation of Affinity Capillary Electrophoresis with Mass Spectrometry for the Study of Ligand-Protein Interactions: n-Methylmorpholine Acetate Buffer and Polydopamine-Based Coating as Key Assets

The direct and precise assessment of ligand-protein interactions under nearly physiological conditions is the core of drug discovery. In this context, affinity capillary electrophoresis (ACE) has become an emerging and reliable approach. The hyphenation of ACE with mass spectrometry (MS) is even more powerful than the classical ACE-UV methodology. It reduces compound identification errors and increases throughput by facilitating the analysis of the mixtures. However, buffers and capillary coatings compatible with mass spectrometry and operating under physiological conditions are very limited. In this paper, n-methylmorpholine acetate buffer and polydopamine-based coating were highlighted as major assets for CE-MS studies involving native proteins. Thanks to its protein desorption property, n-methylmorpholine improved the peak shape of proteins during CE analysis at physiological pH. The polydopamine-based neutral coating developed in this study is simple to prepare and demonstrated high stability at pH 7.4, enabling its use with an MS detector. The combination of these two key elements enabled us to successfully convert our ACE-UV method for coagulation factor XIIa into an ACE-MS approach operating at physiological pH. This study extends the scope of ACE for medicinal chemistry projects.

Targeted Therapies: The Role of Monoclonal Antibodies in Disease Management

Monoclonal antibodies (mAbs) are a key class of biotherapeutic medicines used to treat a wide range of diseases, such as cancer, infectious diseases, autoimmune disorders, cardiovascular diseases, and hemophilia. They can be engineered for greater effectiveness and specific applications while maintaining their structural elements for immune targeting. Traditional immunoglobulin treatments have limited therapeutic uses and various adverse effects. That makes mAbs show rapid growth in the pharmaceutical market, with over 250 mAbs in clinical studies. Although mAbs offer higher specificity, they are less effective against complex antigens. They have become essential in treating diseases with limited medical options, providing innovative solutions that improve patients' quality of life through increasing survival rates, shortening the length of stay in hospitals with an improved treatment outcome, and reducing side effects. This review outlines the mechanisms, applications, and advancements of mAbs, highlighting their transformative role in modern medicine and their potential to shape future therapeutic interventions.

Improving the sustainability of biopharmaceutical downstream processing through buffer recycling

The production of biopharmaceuticals is a chemical- and water-intensive process. The consumption of water and chemicals is partly due to the need for many different buffers in large volumes during the downstream process, typically consisting of several chromatography steps. Given the global commitment to the goals for sustainable development and the anticipated growth of the biopharmaceutical market, the consumption of large buffer volumes is expected to become problematic. To address this, we propose the introduction of buffer recycling to reduce the consumption of water and chemicals. For solvent based pharmaceutical processes, solvent recycling through re-distillation is already established, but for water-based processes, this concept is still rather unexplored. In this study, buffer recycling was implemented during the equilibration phase of Protein A chromatography for antibody purification. We have investigated the potential gains of buffer recycling and demonstrated buffer recycling in two technical implementations: buffer recycling in a batch-to-batch process and buffer recycling in a multi-column process. Buffer recycling consists of buffer recovery and buffer reuse. During recovery, buffer that has been used during equilibration is collected and pH adjusted, and during the reuse step, the recovered buffer is reintroduced into the process. By introducing buffer recycling, we could reduce the equilibration buffer consumption by almost 50 % in this phase, corresponding to more than 10 % of the total buffer use in the Protein A protocol, and have seen no changes in antibody yield or purity. Hence, through buffer recycling, we can improve the sustainability in biomanufacturing by using less water and chemicals.

Recombinant Anti-PF4 Antibodies Derived from Patients with Vaccine-Induced Immune Thrombocytopenia and Thrombosis (VITT) Facilitate Research and Laboratory Diagnosis of VITT

BACKGROUND/OBJECTIVES

Adenoviral vector-based vaccines against COVID-19 rarely cause vaccine-induced immune thrombocytopenia and thrombosis (VITT), a severe adverse reaction caused by IgG antibodies against platelet factor 4 (PF4). To study VITT, patient samples are crucial but have become a scarce resource. Recombinant antibodies (rAbs) derived from VITT patient characteristic amino acid sequences of anti-PF4 IgG are an alternative to study VITT pathophysiology.

METHODS

Amino acid sequences of the variable region of immunoglobulin light and heavy chain of anti-PF4 IgG derived from VITT patients were obtained by mass spectrometry sequencing and rAbs were synthetized by reverse-engineering. Six different rAbs were produced: CR23003, CR23004, and CR23005 (from a patient vaccinated with Jcovden, Johnson & Johnson-Janssen (Beerse, Belgium)), CR22046, and CR22050 and CR22066 (from two different patients vaccinated with Vaxzevria, AstraZeneca (Cambridge, UK)). These rAbs were further characterized using anti-PF4 and anti-PF4/heparin IgG ELISAs, rapid anti-PF4 and anti-PF4/polyanion chemiluminescence assays, and PF4-induced platelet activation assay (PIPA) and their capacity to induce procoagulant platelets.

RESULTS

rAbs bound to PF4 alone, but not to PF4/polyanion complexes in rapid chemiluminescence assays. Chemiluminescence assays and both anti-PF4 IgG and anti-PF4 IgG/heparin ELISA showed concentration-dependent PF4 binding of all six rAbs, however, with different reactivities among them. PIPA showed a similar, concentration-dependent platelet activation pattern. rAbs varied in their reactivity and the majority of the tested rAbs were able to induce procoagulant platelets.

CONCLUSIONS

The six rAbs derived from VITT patients reflect VITT-typical binding capacities and the ability to activate platelets. Therefore, these rAbs offer an attractive new option to study VITT pathophysiology.

Development of an Automated Capture-SELEX Device for Efficient Screening of β-Conglycinin Aptamer

β-Conglycinin is the main allergen present in soybeans, and it is causing wide concern due to its notable allergenicity, heat, and digestive enzyme resistance. Screening for aptamers that both recognize β-conglycinin and inhibit the allergic reactions that it triggers is necessary. Conventional aptamer screening is labor-intensive, requires skilled personnel, and has limited reproducibility. To address these limitations, an automated device was developed to enhance the efficiency of aptamer selection in Capture-SELEX. The device achieves highly integrated, reproducible, and accurate contamination control. Using this device, a high-affinity and specific aptamer, β-5, was selected with a Kd = 18.24 ± 2.42 nM for β-conglycinin, as confirmed by isothermal titration calorimetry and fluorescence polarization. Thermodynamic analysis revealed that enthalpy-driven binding and docking simulations clarified the recognition mechanism. Overall, this automated device enables high-efficiency aptamer generation for certain targets, with aptamer β-5 expected to play a vital role in the detection of β-conglycinin and the targeted inhibition of its allergic reaction.

[Variants of biotechnological drugs in dermatology : Status quo and future]

Biotechnological drugs, so-called biopharmaceuticals, have complex structures, have special physicochemical characteristics and are subject to special regulatory laws. In addition to recombinant monoclonal antibodies, proteins and fusion proteins, a large number of biotechnological variations have been developed, of which antibody fragments, nanobodies, peptides, and antibody-drug conjugates in particular have found their way into clinical application. In addition to strategies for the treatment of oncological diseases, chronic inflammatory diseases in particular are being addressed, which are also becoming of great importance in dermatology. The advantages of biopharmaceuticals are increasingly being recognised and developed as part of special strategies for topical application. Due to the rapid development of molecular medicine, new targets for biopharmaceuticals are constantly being identified, and pharmacokinetically favourable biotechnological molecules are being created using refined methods. It can be assumed that this development will lead to even more highly innovative therapeutic and diagnostic options.

A mini review on recent progress of microfluidic systems for antibody development

Objectives

Antibody is specific reagent that be utilized in various field of biomedical research. Monoclonal antibodies are mostly produced using two common techniques namely hybridoma and antibody engineering, which suffer from some limitations such as boring screening procedures, long production time, low efficacy and a degree of automation. To address these limitations, various microfluidics techniques have been developed for the antibody isolation and screening.

Methods

This study specifically investigates nearly recent reports published in peer-reviewed journals indexed in various databases including Web of Science, Scopus, PubMed, Google Scholar, and Science Direct.

Results

In this study, we identified a total of seventy papers from a pool of 130 articles. These papers focus on the application of three major groups of microfluidic platforms, namely valves, microwells, and droplets, in the development of antibodies using hybridoma method and phage display technology. We provide a summary of these applications and also discuss the key findings in this field. Additionally, we illustrate our discussion with several examples to enhance understanding.

Conclusions

Microfluidics has the potential to serve as a valuable tool in streamlining complex laboratory procedures involved in antibody discovery. However, it is important to note that microfluidics is limited to laboratory settings. Further enhancements are needed to address existing challenges and to make microfluidics a reliable, accurate, and cost-effective tool for antibody discovery.

Towards a structural and functional analysis of the immunoglobulin-fold proteome

The immunoglobulin fold (Ig fold) domain is a super-secondary structural motif consisting of a sandwich with two layers of β-sheets that is present in many proteins with very diverse biological functions covering a wide range of physiological processes. This domain presents a modular architecture built with β strands connected by variable length loops that has a highly conserved structural core of four β-strands and quite variable β-sheet extensions in the two sandwich layers that enable both divergent and convergent evolutionary mechanisms in the known Ig fold proteome. The central role of this Ig fold's structural plasticity in the evolutionary success of antibodies in our immune system is well established. Nature has also utilized this Ig fold in all domains of life in many different physiological contexts that go way beyond the immune system. Here we will present a structural and functional overview of the utilization of the Ig fold in different biological processes and in different cellular contexts to highlight some of the innumerable ways that this structural motif can interact in multidomain proteins to enable their diversity of functions. This includes shareable specific protein structure visualizations behind those functions that serve as starting points for further explorations of the biomolecular interactions spanning the Ig fold proteome. This overview also highlights how this Ig fold is being utilized through natural adaptation, engineering, and even building from scratch for a range of biotechnological applications.

Introduction of Carbonyl Groups into Antibodies

Antibodies and their derivatives (scFv, Fabs, etc.) represent a unique class of biomolecules that combine selectivity with the ability to target drug delivery. Currently, one of the most promising endeavors in this field is the development of molecular diagnostic tools and antibody-based therapeutic agents, including antibody-drug conjugates (ADCs). To meet this challenge, it is imperative to advance methods for modifying antibodies. A particularly promising strategy involves the introduction of carbonyl groups into the antibody that are amenable to further modification by biorthogonal reactions, namely aliphatic, aromatic, and α-oxo aldehydes, as well as aliphatic and aryl-alkyl ketones. In this review, we summarize the preparation methods and applications of site-specific antibody conjugates that are synthesized using this approach.

Revolutionizing cancer immunotherapy: unleashing the potential of bispecific antibodies for targeted treatment

Recent progressions in immunotherapy have transformed cancer treatment, providing a promising strategy that activates the immune system of the patient to find and eliminate cancerous cells. Bispecific antibodies, which engage two separate antigens or one antigen with two distinct epitopes, are of tremendous concern in immunotherapy. The bi-targeting idea enabled by bispecific antibodies (BsAbs) is especially attractive from a medical standpoint since most diseases are complex, involving several receptors, ligands, and signaling pathways. Several research look into the processes in which BsAbs identify different cancer targets such angiogenesis, reproduction, metastasis, and immune regulation. By rerouting cells or altering other pathways, the bispecific proteins perform effector activities in addition to those of natural antibodies. This opens up a wide range of clinical applications and helps patients with resistant tumors respond better to medication. Yet, further study is necessary to identify the best conditions where to use these medications for treating tumor, their appropriate combination partners, and methods to reduce toxicity. In this review, we provide insights into the BsAb format classification based on their composition and symmetry, as well as the delivery mode, focus on the action mechanism of the molecule, and discuss the challenges and future perspectives in BsAb development.