Chimerization and characterization of a monoclonal antibody with potent neutralizing activity across multiple influenza A H5N1 clades

A paradigm use of monoclonal antibodies-conjugated nanoparticles in breast cancer treatment: current status and potential approaches

Monoclonal antibodies (mAbs) are integral to cancer treatment over conventional non-specific therapy methods. This study provides a scoping review of the clinically approved mAbs, focusing on the current application of different nanocarrier technologies as drug delivery targets for mAb-conjugated nanoparticles (NPs) as potential features for breast cancer (BC) treatment. An extensive literature search was conducted between the years 2000 and 2023 using various sources of databases. The first part covered mAb classification, types, and mechanisms of action, pharmacokinetics and clinical applications in BC. The second part covered polymeric, lipid and inorganic-based NPs, which are a variety of mAb-conjugated NPs targeting BC. A total of 20 relevant studies were enrolled indicating there are three different types of nanoparticular systems (polymeric NPs, inorganic NPs and lipid-based NPs) that can be used for BC treatment by being loaded with various active substances and conjugated with these antibodies. While mAbs have altered the way in cancer treatment due to targeting cancer cells specifically, the delivery of mAbs with nanoparticulate systems is important in the treatment of BC, as NPs are still being investigated as distinctive and promising drug delivery methods that can be employed for effective treatment of BC.

Clinically Approved Monoclonal Antibodies-based Immunotherapy: Association With Glycemic Control and Impact Role of Clinical Pharmacist for Cancer Patient Care

PURPOSE

Compared with more conventional, nonspecific therapy options, such as radiotherapy and chemotherapy, monoclonal antibodies (mAbs) constitute a crucial approach of cancer treatment. Multiple autoimmune diseases have been observed during treatment with mAb medications, including autoimmune diabetes mellitus (DM). This study provides a narrative review of clinically approved mAbs in cancer treatment and focuses on the development of hyperglycemia and DM arising from using these therapies. Furthermore, it highlights the critical role of oncology clinical pharmacists in the management of autoimmune DM and patient care while using these medications in an oncology setting.

METHODS

An extensive literature search was conducted using various sources of electronic databases, such as Scopus, Embase, Web of Science, and PubMed, and search engines, such as Google Scholar, for studies on mAb classification, types, mechanisms of action, pharmacokinetic properties, current clinical applications, and the associated common adverse effects with significant recommendations for patient care in an oncology setting, along with focusing on the proposed mechanisms and clinical studies that reported the association of DM after the use of these therapies.

FINDINGS

There are 4 types (murine, chimeric, humanized, and human) and 3 classes (unconjugated, conjugated, and bispecific) of mAbs with several mechanisms of action that can destroy cancer cells, including preventing tumor cell survival cascades, inhibiting tumor growth by interfering with tumor angiogenesis, evading programmed cell death, and bypassing immune checkpoints. However, multiple endocrinopathies, autoimmune diseases, and complications were reported from the use of these medications, including the development of autoimmune DM and diabetic ketoacidosis. These autoimmune disorders were reported most with the use of immune checkpoint inhibitors, including inhibitors of the programmed cell death protein 1 (nivolumab and pembrolizumab), its ligand (atezolizumab, avelumab, and durvalumab), and cytotoxic T-lymphocyte-associated protein 4 (ipilimumab).

IMPLICATIONS

mAbs are considered important approaches for the treatment of many cancer types. However, a high incidence of hyperglycemia, type 1 DM, and diabetic ketoacidosis is observed with the use of these medications, particularly immune checkpoint inhibitors. It is important for oncologic clinical pharmacists to be involved in addressing these autoimmune disorders from the use of these immunotherapies via the provision of patient education, medication adherence support, close monitoring, and follow-up, which will lead to better health-related outcomes and improved patient quality of life.

Analysis of the conserved protective epitopes of hemagglutinin on influenza A viruses

The conserved protective epitopes of hemagglutinin (HA) are essential to the design of a universal influenza vaccine and new targeted therapeutic agents. Over the last 15 years, numerous broadly neutralizing antibodies (bnAbs) targeting the HA of influenza A viruses have been isolated from B lymphocytes of human donors and mouse models, and their binding epitopes identified. This work has brought new perspectives for identifying conserved protective epitopes of HA. In this review, we succinctly analyzed and summarized the antigenic epitopes and functions of more than 70 kinds of bnAb. The highly conserved protective epitopes are concentrated on five regions of HA: the hydrophobic groove, the receptor-binding site, the occluded epitope region of the HA monomers interface, the fusion peptide region, and the vestigial esterase subdomain. Our analysis clarifies the distribution of the conserved protective epitope regions on HA and provides distinct targets for the design of novel vaccines and therapeutics to combat influenza A virus infection.

Contribution of Fc-dependent cell-mediated activity of a vestigial esterase-targeting antibody against H5N6 virus infection

The highly pathogenic avian influenza A (H5N6) virus has caused sporadic human infections with a high case fatality rate. Due to the continuous evolution of this virus subtype and its ability to transmit to humans, there is an urgent need to develop effective antiviral therapeutics. In this study, a murine monoclonal antibody 9F4 was shown to display broad binding affinity against H5Nx viruses. Furthermore, 9F4 can neutralize H5N6 pseudotyped particles and prevent entry into host cells. Additionally, ADCC/ADCP deficient L234A, L235A (LALA) and CDC deficient K322A mutants were generated and displayed comparable binding affinity and neutralizing activity as wild type 9F4 (9F4-WT). Notably, 9F4-WT, 9F4-LALA and 9F4-K322A exhibit in vivo protective efficacies against H5N6 infections in that they were able to reduce viral loads in mice. However, only 9F4-WT and 9F4-K322A but not 9F4-LALA were able to reduce viral pathogenesis in H5N6 challenged mice. Furthermore, depletion of phagocytic cells in mice lungs nullifies 9F4-WT's protection against H5N6 infections, suggesting a crucial role of the host's immune cells in 9F4 antiviral activity. Collectively, these findings reveal the importance of ADCC/ADCP function for 9F4-WT protection against HPAIV H5N6 and demonstrate the potential of 9F4 to confer protection against the reassortant H5-subtype HPAIVs.

IgA tetramerization improves target breadth but not peak potency of functionality of anti-influenza virus broadly neutralizing antibody

Mucosal immunoglobulins comprise mainly secretory IgA antibodies (SIgAs), which are the major contributor to pathogen-specific immune responses in mucosal tissues. These SIgAs are highly heterogeneous in terms of their quaternary structure. A recent report shows that the polymerization status of SIgA defines their functionality in the human upper respiratory mucosa. Higher order polymerization of SIgA (i.e., tetramers) leads to a marked increase in neutralizing activity against influenza viruses. However, the precise molecular mechanisms underlying the effects of SIgA polymerization remain elusive. Here, we developed a method for generating recombinant tetrameric monoclonal SIgAs. We then compared the anti-viral activities of these tetrameric SIgAs, which possessed variable regions identical to that of a broadly neutralizing anti-influenza antibody F045-092 against influenza A viruses, with that of monomeric IgG or IgA. The tetrameric SIgA showed anti-viral inhibitory activity superior to that of other forms only when the antibody exhibits low-affinity binding to the target. By contrast, SIgA tetramerization did not substantially modify anti-viral activity against targets with high-affinity binding. Taken together, the data suggest that tetramerization of SIgA improved target breadth, but not peak potency of antiviral functions of the broadly neutralizing anti-influenza antibody. This phenomenon presumably represents one of the mechanisms by which SIgAs present in human respiratory mucosa prevent infection by antigen-drifted influenza viruses. Understanding the mechanisms involved in cross neutralization of viruses by SIgAs might facilitate the development of vaccine strategies against viral infection of mucosal tissues.

SIgAs exist as mainly dimers and tetramers and play critical roles in mucosal immune responses against influenza. Detailed characterization of these anti-viral SIgA is important for better understanding of the mechanisms underlying anti-viral immunity. Here, we describe a means of generating a recombinant tetrameric monoclonal SIgA to enable exhaustive characterization of tetrameric SIgAs. The tetrameric monoclonal SIgA possessing variable regions of anti-influenza viruses broadly neutralizing antibody show that tetramerization of SIgA improves target breadth, but not the peak potency, of their anti-viral functions. These results broaden our knowledge about the fundamental role of SIgA tetramerization in anti-viral humoral response at the human respiratory mucosa.

The Vestigial Esterase Domain of Haemagglutinin of H5N1 Avian Influenza A Virus: Antigenicity and Contribution to Viral Pathogenesis

Initial attempts to develop monoclonal antibodies as therapeutics to resolve influenza infections focused mainly on searching for antibodies with the potential to neutralise the virus in vitro with classical haemagglutination inhibition and microneutralisation assays. This led to the identification of many antibodies that bind to the head domain of haemagglutinin (HA), which generally have potent neutralisation capabilities that block viral entry or viral membrane fusion. However, this class of antibodies has a narrow breadth of protection in that they are usually strain-specific. This led to the emphasis on stalk-targeting antibodies, which are able to bind a broad range of viral targets that span across different influenza subtypes. Recently, a third class of antibodies targeting the vestigial esterase (VE) domain have been characterised. In this review, we describe the key features of neutralising VE-targeting antibodies and compare them with head- and stalk-class antibodies.

Influenza virus antigenicity and broadly neutralizing epitopes

A vaccine formulation that would be effective against all strains of influenza virus has long been a goal of vaccine developers, but antibodies after infection or vaccination were seen to be strain specific and there was little evidence of cross-reactive antibodies that neutralized across subtypes. Recently a number of broadly neutralizing monoclonal antibodies have been characterized. This review describes the different classes of broadly neutralizing antibodies and discusses the potential of their therapeutic use or for design of immunogens that induce a high proportion of broadly neutralizing antibodies.