Mechanisms of Action and Limitations of Monoclonal Antibodies and Single Chain Fragment Variable (scFv) in the Treatment of Cancer

C. S, Devkota HP, Khadka D. Immune Modulation and Immunotherapy in Solid Tumors: Mechanisms of Resistance and Potential Therapeutic Strategies

Understanding the modulation of specific immune cells within the tumor microenvironment (TME) offers new hope in cancer treatments, especially in cancer immunotherapies. In recent years, immune modulation and resistance to immunotherapy have become critical challenges in cancer treatments. However, novel strategies for immune modulation have emerged as promising approaches for oncology due to the vital roles of the immunomodulators in regulating tumor progression and metastasis and modulating immunological responses to standard of care in cancer treatments. With the progress in immuno-oncology, a growing number of novel immunomodulators and mechanisms are being uncovered, offering the potential for enhanced clinical immunotherapy in the near future. Thus, gaining a comprehensive understanding of the broader context is essential. Herein, we particularly summarize the paradoxical role of tumor-related immune cells, focusing on how targeted immune cells and their actions are modulated by immunotherapies to overcome immunotherapeutic resistance in tumor cells. We also highlight the molecular mechanisms employed by tumors to evade the long-term effects of immunotherapeutic agents, rendering them ineffective.

Whole-canine neutralizing antibodies generated by single B cell antibody technology elicit therapeutic protection against canine distemper virus infection

Canine distemper virus (CDV) causes a highly contagious and fatal disease in domestic and wild carnivores. Currently, vaccination is the primary method for preventing canine distemper. However, incidents of vaccine immunization failures continue to be reported. There are no specific and effective treatment agents available for canine distemper infection. Neutralizing antibodies offer a potential approach for the treatment of viral diseases. In this study, single B cell antibody technology was applied to obtain whole-canine antibodies against CDV. 7 monoclonal antibodies were screened and showed high binding affinity to CDV hemagglutinin (H) protein, with D16 and F53 exhibited high specificity and neutralizing activity against CDV. Furthermore, D16 exhibited effective therapeutic potential in dogs subjected to lethal dose CDV attacks in vivo. In conclusion, our study offers an alternative approach for acquiring neutralizing antibody and provides a promising new strategy for the treatment of CDV infection.

The Use of Plant Viral Nanoparticles in Cancer Biotherapy-A Review

Cancer is a major global health problem that poses significant challenges. Conventional cancer therapies often have severe side effects, necessitating the development of novel therapeutic approaches that are more effective and less toxic. The utilization of plant viral nanoparticles is one of the more promising strategies for cancer biotherapy. Plant viral nanoparticles exhibit advantageous properties, including safety, high stability, rapid production and scalability, biocompatibility and biodegradability, structural uniformity, inherent immunogenicity, ease of modification and high update efficacy as well as lower cost implications, making them attractive vehicles for health applications. Various studies have demonstrated the efficacy of plant viral nanoparticles in targeted therapeutic drug/molecule delivery, tumor imaging and immunotherapy, highlighting their potential as a versatile platform for cancer biotherapy. The drawbacks of plant viral nanoparticles include their perceived ability to induce a hypersensitive/allergic immune response, non-well-defined regulatory approval processes as well as the reluctance of pharmaceutical companies to adapt their manufacturing processes to facilitate plant-based expression. This review discusses applications of plant virus-derived nanoparticles in cancer therapeutics and prospects for translating these findings into clinical practice.

Exploring CAR-PBMCs: A Novel Strategy Against EGFR-Positive Tumor Cells

Background: Chimeric antigen receptor (CAR) T cell therapy has shown significant promise in treating hematological malignancies, yet its application in solid tumors, particularly those expressing the epidermal growth factor receptor (EGFR), remains limited. This study investigates the potential of CAR-engineered peripheral blood mononuclear cells (PBMCs) as a novel adoptive cell therapy against EGFR-positive cancers. Methods: Lentiviral transduction at an MOI of 50 was performed to generate specific anti-EGFR second generation CAR-effector cells. The transduced PBMCs were stimulated with cytokines and CD3/CD28 beads to enhance their proliferation and activation. Flow cytometric and real-time cell analysis were performed at various effector-to-target ratios to explore the cytotoxic potential of CAR-PBMCs. Results: CAR-PBMCs exhibited improved targeting and cytotoxicity against EGFR-positive cancer cell lines MDA-MB-468 and SK-BR-3, compared to untransduced controls, with unsignificant effects on allogeneic PBMCs. Conclusion: CAR-PBMCs hold considerable potential as a therapeutic strategy for EGFR-positive solid tumors, warranting further clinical investigation.

Antibody numbering schemes: advances, comparisons and tools for antibody engineering

The evolution of antibody engineering has significantly enhanced the development of antibody-based therapeutics, enabling the creation of novel antibody formats tailored for specific applications. Since the introduction of the Kabat numbering scheme in 1977, various schemes have been developed and modified, forming the foundation for multiple antibody engineering projects. The tools associated with these schemes further facilitate the engineering process. However, discrepancies among current numbering schemes can lead to confusion. This study examines various numbering schemes and related tools, providing new insights into antibody variable domains. Improved understanding of antibody numbering and related tools holds significant potential for more precise and efficient antibody design, thereby advancing antibody-based therapeutics and diagnostics.

Single chain fragment variable, a new theranostic approach for cardiovascular diseases

Cardiovascular diseases (CVDs) remain a significant global health challenge, leading to substantial morbidity and mortality. Despite recent advancements in CVD management, pharmaceutical treatments often suffer from poor pharmacokinetics and high toxicity. With the rapid progress of modern molecular biology and immunology, however, single-chain fragment variable (scFv) molecule engineering has emerged as a promising theranostic tool to offer specificity and versatility in targeting CVD-related antigens. To represent the latest development on the potential of scFv in the context of CVDs, this review summarized the new mechanism of action and applications as therapeutic, as well as diagnostic agents. Furthermore, the advantages of scFv, including its small size, ease of modification, and ability to be engineered for enhanced affinity and specificity, are also described. Finally, such challenges as immunogenicity, stability, and scalability, alongside strategies to overcome these hurdles, are deeply scrutinized to provide safer and more effective strategies for the diagnosis and treatment of the incurable CVDs.

B7-H3 in glioblastoma and beyond: significance and therapeutic strategies

Cancer has emerged as the second most prevalent disease and the leading cause of death, claiming the lives of 10 million individuals each year. The predominant varieties of cancer encompass breast, lung, colon, rectal, and prostate cancers. Among the more aggressive malignancies is glioblastoma, categorized as WHO stage 4 brain cancer. Following diagnosis, the typical life expectancy ranges from 12 to 15 months, as current established treatments like surgical intervention, radiotherapy, and chemotherapy using temozolomide exhibit limited effectiveness. Beyond conventional approaches, the exploration of immunotherapy for glioblastoma treatment is underway. A methodology involves CAR-T cells, monoclonal antibodies, ADCC and nanobodies sourced from camelids. Immunotherapy's recent focal point is the cellular ligand B7-H3, notably abundant in tumor cells while either scarce or absent in normal ones. Its expression elevates with cancer progression and serves as a promising prognostic marker. In this article, we delve into the essence of B7-H3, elucidating its function and involvement in signaling pathways. We delineate the receptors it binds to and its significance in glioblastoma and other cancer types. Lastly, we examine its role in immunotherapy and the utilization of nanobodies in this domain.

Therapeutic antibodies in oncology: an immunopharmacological overview

The biotechnological development of monoclonal antibodies and their immunotherapeutic use in oncology have grown exponentially in the last decade, becoming the first-line therapy for some types of cancer. Their mechanism of action is based on the ability to regulate the immune system or by interacting with targets that are either overexpressed in tumor cells, released into the extracellular milieu or involved in processes that favor tumor growth. In addition, the intrinsic characteristics of each subclass of antibodies provide specific effector functions against the tumor by activating antibody-dependent cellular cytotoxicity, complement-dependent cytotoxicity, and antibody-dependent cellular phagocytosis, among other mechanisms. The rational design and engineering of monoclonal antibodies have improved their pharmacokinetic and pharmacodynamic features, thus optimizing the therapeutic regimens administered to cancer patients and improving their clinical outcomes. The selection of the immunoglobulin G subclass, modifications to its crystallizable region (Fc), and conjugation of radioactive substances or antineoplastic drugs may all improve the antitumor effects of therapeutic antibodies. This review aims to provide insights into the immunological and pharmacological aspects of therapeutic antibodies used in oncology, with a rational approach at molecular modifications that can be introduced into these biological tools, improving their efficacy in the treatment of cancer.

Monoclonal Antibodies for the Treatment of Ocular Diseases

Monoclonal antibodies (mAbs) have revolutionized the landscape of cancer therapy, offering unprecedented specificity and diverse mechanisms to combat malignant cells. These biologic agents have emerged as a cornerstone in targeted cancer treatment, binding to specific antigens on cancer cells and exerting their therapeutic effects through various mechanisms, including inhibition of signaling pathways, antibody-dependent cellular cytotoxicity (ADCC), complement-dependent cytotoxicity (CDC), and antibody-dependent cellular phagocytosis (ADCP). The unique ability of mAbs to engage the immune system and directly interfere with cancer cell function has significantly enhanced the therapeutic armamentarium against a broad spectrum of malignancies. mAbs were initially studied in oncology; however, today, treatments have been developed for eye diseases. This review discusses the current applications of mAbs for the treatment of ocular diseases, discussing the specificity and the variety of mechanisms by which these molecules exhibit their therapeutic effects. The benefits, drawbacks, effectiveness, and risks associated with using mAbs in ophthalmology are highlighted, focusing on the most relevant ocular diseases and mAbs currently in use. Technological advances have led to in vitro production methods and recombinant engineering techniques, allowing the development of chimeric, humanized, and fully human mAbs. Nowadays, many humanized mAbs have several applications, e.g., for the treatment of age-related macular disease, diabetic retinopathy, and uveitis, while studies about new applications of mAbs, such as for SARS-CoV-2 infection, are also currently ongoing to seek more efficient and safe approaches to treat this new ocular disease.

Breast cancer immunotherapy using scFv antibody-based approaches, a systematic review

Breast cancer is considered as the most common malignancy in women and the second leading cause of death related to cancer. Recombinant DNA technologies accelerated the development of antibody-based cancer therapy, which is effective in a broad range of cancers. The objective of the present study was to perform a systematic review on breast cancer immunotherapy using single-chain fragment variable (scFv) antibody formats. Searches were performed up to March 2023 using PubMed, Scopus, and Web of Science (ISI) databases. Three reviewers independently assessed study eligibility, data extraction, and evaluated the methodological quality of included primary studies. Different immunotherapy approaches have been identified and the most common approaches were scFv-conjugates, followed by simple scFvs and chimeric antigen receptor (CAR) therapy, respectively. Among breast cancer antigens, HER superfamily, CD family, and EpCAM were applied as the most important breast cancer immunotherapy targets. The present study shed more lights on scFv-based breast cancer immunotherapy approaches.

Comparison of single-chain variable fragments and monoclonal antibody against dihydroartemisinin

Immunoassay relies on antibodies, but traditional antibodies such as monoclonal antibody (mAb) require animal immunization and complex procedures. Single-chain variable fragment (scFv) becomes a potential alternative to mAb with advantages of the low cost, rapid and easy prepared. In the present study, we prepared scFvs against dihydroartemisinin (DHA) based on E. coli and HEK293T cell expression system, named MBP-scFv and scFv-Fc, respectively. Their properties were compared with the parent mAb. The calculated affinity constants of mAb, MBP-scFv and scFv-Fc were 2.1 × 108 L mol-1, 2.2 × 107 L mol-1 and 1.6 × 108 L mol-1, respectively. The half inhibitory concentration (IC50) of mAb, MBP-scFv and scFv-Fc were 1.16 ng mL-1, 2.15 ng mL-1 and 6.57 ng mL-1, respectively. Both the scFv showed less sensitive than the mAb based on the IC50. The cross-reactivities of MBP-scFv for artemisinin and artesunate exhibited similarities to the mAb, yet the cross-reactivities of scFv-Fc for these compounds exceeded those of the mAb significantly. The stability of the scFvs was ascertained to be maintained for over 5 days at room temperature, and for more than a month at both 4 °C and - 20 °C. After that, the indirect competitive enzyme-linked immunosorbent assays (icELISAs) based on the scFv from E. coli were used to detect the DHA content in eight drug samples, and the result was consistent with ultra-performance liquid chromatography simultaneously. Although scFv can be used for quantitative determination of drugs, but it still cannot completely replace mAb in immunoassay without evolution and modification.

Exploring treatment options in cancer: Tumor treatment strategies

Traditional therapeutic approaches such as chemotherapy and radiation therapy have burdened cancer patients with onerous physical and psychological challenges. Encouragingly, the landscape of tumor treatment has undergone a comprehensive and remarkable transformation. Emerging as fervently pursued modalities are small molecule targeted agents, antibody-drug conjugates (ADCs), cell-based therapies, and gene therapy. These cutting-edge treatment modalities not only afford personalized and precise tumor targeting, but also provide patients with enhanced therapeutic comfort and the potential to impede disease progression. Nonetheless, it is acknowledged that these therapeutic strategies still harbour untapped potential for further advancement. Gaining a comprehensive understanding of the merits and limitations of these treatment modalities holds the promise of offering novel perspectives for clinical practice and foundational research endeavours. In this review, we discussed the different treatment modalities, including small molecule targeted drugs, peptide drugs, antibody drugs, cell therapy, and gene therapy. It will provide a detailed explanation of each method, addressing their status of development, clinical challenges, and potential solutions. The aim is to assist clinicians and researchers in gaining a deeper understanding of these diverse treatment options, enabling them to carry out effective treatment and advance their research more efficiently.

Targeting apoptosis in clear cell renal cell carcinoma

Clear cell renal cell carcinoma (ccRCC) is the most prevalent subtype of renal cancer, accounting for approximately 80% of all renal cell cancers. Due to its exceptional inter- and intratumor heterogeneity, it is highly resistant to conventional systemic therapies. Targeting the evasion of cell death, one of cancer's hallmarks, is currently emerging as an alternative strategy for ccRCC. In this article, we review the current state of apoptosis-inducing therapies against ccRCC, including antisense oligonucleotides, BH3 mimetics, histone deacetylase inhibitors, cyclin-kinase inhibitors, inhibitors of apoptosis protein antagonists, and monoclonal antibodies. Although preclinical studies have shown encouraging results, these compounds fail to improve patients' outcomes significantly. Current evidence suggests that inducing apoptosis in ccRCC may promote tumor progression through apoptosis-induced proliferation, anastasis, and apoptosis-induced nuclear expulsion. Therefore, re-evaluating this approach is expected to enable successful preclinical-to-clinical translation.

Advancement in the development of single chain antibodies using phage display technology

Phage display technology has become an important research tool in biological research, fundamentally changing the traditional monoclonal antibody preparation process, and has been widely used in the establishment of antigen-antibody libraries, drug design, vaccine research, pathogen detection, gene therapy, antigenic epitope research, and cellular signal transduction research.The phage display is a powerful platform for technology development. Using phage display technology, single chain fragment variable (scFv) can be screened, replacing the disadvantage of the large size of traditional antibodies. Phage display single chain antibody libraries have significant biological implications. Here we describe the types of antibodies, including chimeric antibodies, bispecific antibodies, and scFvs. In addition, we describe the phage display system, phage display single chain antibody libraries, screening of specific antibodies by phage libraries and the application of phage libraries.

CD19/CD20 dual-targeted chimeric antigen receptor-engineered natural killer cells exhibit improved cytotoxicity against acute lymphoblastic leukemia

BACKGROUND

Chimeric antigen receptor natural killer (CAR-NK) cells represent a promising advancement in CAR cell therapy, addressing limitations observed in CAR-T cell therapy. However, our prior study revealed challenges in CAR-NK cells targeting CD19 antigens, as they failed to eliminate CD19+ Raji cells in NSG tumor-bearing mice, noting down-regulation or loss of CD19 antigen expression in some Raji cells. In response, this study aims to enhance CD19 CAR-NK cell efficacy and mitigate the risk of tumor recurrence due to target antigen escape by developing CD19 and CD20 (CD19/CD20) dual-targeted CAR-NK cells.

METHODS

Initially, mRNA encoding anti-CD19 CARs (FMC63 scFv-CD8α-4-1BB-CD3ζ) and anti-CD20 CARs (LEU16 scFv-CD8α-4-1BB-CD3ζ) was constructed via in vitro transcription. Subsequently, CD19/CD20 dual-targeted CAR-NK cells were generated through simultaneous electrotransfection of CD19/CD20 CAR mRNA into umbilical cord blood-derived NK cells (UCB-NK).

RESULTS

Following co-electroporation, the percentage of dual-CAR expression on NK cells was 86.4% ± 1.83%, as determined by flow cytometry. CAR expression was detectable at 8 h post-electric transfer, peaked at 24 h, and remained detectable at 96 h. CD19/CD20 dual-targeted CAR-NK cells exhibited increased specific cytotoxicity against acute lymphoblastic leukemia (ALL) cell lines (BALL-1: CD19+CD20+, REH: CD19+CD20-, Jurkat: CD19-CD20-) compared to UCB-NK, CD19 CAR-NK, and CD20 CAR-NK cells. Moreover, CD19/CD20 dual-targeted CAR-NK cells released elevated levels of perforin, IFN-γ, and IL-15. Multiple activation markers such as CD69 and cytotoxic substances were highly expressed.

CONCLUSIONS

The creation of CD19/CD20 dual-targeted CAR-NK cells addressed the risk of tumor escape due to antigen heterogeneity in ALL, offering efficient and safe 'off-the-shelf' cell products. These cells demonstrate efficacy in targeting CD20 and/or CD19 antigens in ALL, laying an experimental foundation for their application in ALL treatment.

The role of podoplanin inhibitors in controlling oral cancer progression

OBJECTIVE

In this article, we review the current studies on the role of podoplanin in oral cancer and the potential application of podoplanin inhibitors as a therapeutic agent for oral cancer.

DESIGN

The narrative review approach was conducted, providing a comprehensive perspective of related literature. Publications addressing podoplanin and its inhibitors in the context of oral cancer were retrieved from PubMed and Scopus databases.

RESULTS

Podoplanin has emerged as a biomarker and therapeutic agent for oral cancer. Numerous studies have reported high podoplanin expression in oral cancer and pre-cancerous lesions compared to normal cells. A specific inhibitor targeting podoplanin may have the potential to prevent oral carcinogenesis via interfering with the pathway of cancerous cells involved in cell proliferation and metastasis. Antibodies, chimeric antigen receptor (CAR)-T cells, cancer-specific mAb (CasMab), synthetic molecules, and lectins are among the materials used as anticancer agents targeting podoplanin. Plant-derived lectins appear to demonstrate a unique advantage against alternative candidates.

CONCLUSIONS

The use of podoplanin inhibitors in place of existing therapeutic approaches could be a promising and novel approach to the prevention and treatment of oral cancer. Nevertheless, further research is required to investigate the practical application of such inhibitors.

Recent Advances in the Development of Monoclonal Antibodies and Next-Generation Antibodies

mAbs are highly indispensable tools for diagnostic, prophylactic, and therapeutic applications. The first technique, hybridoma technology, was based on fusion of B lymphocytes with myeloma cells, which resulted in generation of single mAbs against a specific Ag. Along with hybridoma technology, several novel and alternative methods have been developed to improve mAb generation, ranging from electrofusion to the discovery of completely novel technologies such as B cell immortalization; phage, yeast, bacterial, ribosome, and mammalian display systems; DNA/RNA encoded Abs; single B cell technology; transgenic animals; and artificial intelligence/machine learning. This commentary outlines the evolution, methodology, advantages, and limitations of various mAb production techniques. Furthermore, with the advent of next-generation Ab technologies such as single-chain variable fragments, nanobodies, bispecific Abs, Fc-engineered Abs, Ab biosimilars, Ab mimetics, and Ab-drug conjugates, the healthcare and pharmaceutical sectors have become resourceful to develop highly specific mAb treatments against various diseases such as cancer and autoimmune and infectious diseases.

Therapeutic Targets of Monoclonal Antibodies Used in the Treatment of Cancer: Current and Emerging

Cancer is one of the leading global causes of death and disease, and treatment options are constantly evolving. In this sense, the use of monoclonal antibodies (mAbs) in immunotherapy has been considered a fundamental aspect of modern cancer therapy. In order to avoid collateral damage, it is indispensable to identify specific molecular targets or biomarkers of therapy and/or diagnosis (theragnostic) when designing an appropriate immunotherapeutic regimen for any type of cancer. Furthermore, it is important to understand the currently employed mAbs in immunotherapy and their mechanisms of action in combating cancer. To achieve this, a comprehensive understanding of the biology of cancer cell antigens, domains, and functions is necessary, including both those presently utilized and those emerging as potential targets for the design of new mAbs in cancer treatment. This review aims to provide a description of the therapeutic targets utilized in cancer immunotherapy over the past 5 years, as well as emerging targets that hold promise as potential therapeutic options in the application of mAbs for immunotherapy. Additionally, the review explores the mechanisms of actin of the currently employed mAbs in immunotherapy.