Advancements in mRNA Encoded Antibodies for Passive Immunotherapy

Optimized inhaled LNP formulation for enhanced treatment of idiopathic pulmonary fibrosis via mRNA-mediated antibody therapy

Lipid nanoparticle-assisted mRNA inhalation therapy necessitates addressing challenges such as resistance to shear force damage, mucus penetration, cellular internalization, rapid lysosomal escape, and target protein expression. Here, we introduce the innovative "LOOP" platform with a four-step workflow to develop inhaled lipid nanoparticles specifically for pulmonary mRNA delivery. iLNP-HP08LOOP featuring a high helper lipid ratio, acidic dialysis buffer, and excipient-assisted nebulization buffer, demonstrates exceptional stability and enhanced mRNA expression in the lungs. By incorporating mRNA encoding IL-11 single chain fragment variable (scFv), scFv@iLNP-HP08LOOP effectively delivers and secretes IL-11 scFv to the lungs of male mice, significantly inhibiting fibrosis. This formulation surpasses both inhaled and intravenously injected IL-11 scFv in inhibiting fibroblast activation and extracellular matrix deposition. The HP08LOOP system is also compatible with commercially available ALC0315 LNPs. Thus, the "LOOP" method presents a powerful platform for developing inhaled mRNA nanotherapeutics with potential for treating various respiratory diseases, including idiopathic pulmonary fibrosis.

Triphenylphosphonium-modified catiomers enhance in vivo mRNA delivery through stabilized polyion complexation

Nanocarriers based on cationic materials play a central role in the success of mRNA-based therapies. Traditionally, amine-bearing lipids and polymers have been successfully employed for creating mRNA-loaded nanocarriers, though they still present challenges, such as physical and biological instability, limiting both delivery efficiency and therapeutic potential. Non-amine cations could be a promising avenue in addressing these limitations. However, such alternatives remain notably underexplored. Herein, we introduced triphenylphosphonium (TPP) as an alternative cationic moiety for mRNA delivery, leveraging its advantageous properties for nucleic acid complexation. Through the modification of amine-bearing catiomers, we replaced traditional amine-based counterparts with TPP to create innovative polymeric micelles as mRNA nanocarriers. A comprehensive analysis, encompassing physicochemical, thermodynamic, and computational approaches, revealed that the TPP substitution significantly influenced polymer self-assembly, mRNA binding, and the overall stability of mRNA-loaded polymeric micelles. Upon intravenous injection, TPP-bearing micelles demonstrated a remarkable increase in mRNA bioavailability, facilitating efficient protein production in solid tumors. These findings provide a compelling rationale for substituting amines with TPP, emphasizing their potential for advancing mRNA therapeutics.

Deconvolution of synthetic mRNA expression: Nucleoside chemistry alters translatability

Recent technological advances in the production of in vitro transcribed messenger RNA (IVT-mRNA) facilitate its clinical use as well as its application in basic research. In this regard, numerous chemical modifications, which are not naturally observed in endogenous mRNA, have been implemented primarily to address the issue of immunogenicity and improve its biological performance. However, recent findings suggested pronounced differences between expression levels of IVT-mRNAs with different nucleoside modifications in transfected cells. Given the multistep process of IVT-mRNA delivery and subsequent intracellular expression, it is unclear which step is influenced by IVT-mRNA chemistry. Here, we deconvolute this process and show that the nucleoside modification does not interfere with complexation of carriers, their physicochemical properties, and extracellular stability, as exemplified by selected modifications. The immediate effect of mRNA chemistry on the efficiency of ribosomal protein synthesis as a contributor to differences in expression was quantified by in vitro cell-free translation. Our results demonstrate that for the nucleoside modifications tested, translatability was the decisive step in determining overall protein production. Also of special importance for future work on rational selection of tailored synthetic mRNA chemistries, our findings set a workflow to identify potentially limiting, modification-dependent steps in the complex delivery process.

Unlocking the Therapeutic Applicability of LNP-mRNA: Chemistry, Formulation, and Clinical Strategies

Messenger RNA (mRNA) has emerged as an innovative therapeutic modality, offering promising avenues for the prevention and treatment of a variety of diseases. The tremendous success of mRNA vaccines in effectively combatting coronavirus disease 2019 (COVID-19) evidences the unlimited medical and therapeutic potential of mRNA technology. Overcoming challenges related to mRNA stability, immunogenicity, and precision targeting has been made possible by recent advancements in lipid nanoparticles (LNPs). This review summarizes state-of-the-art LNP-mRNA-based therapeutics, including their structure, material compositions, design guidelines, and screening principles. Additionally, we highlight current preclinical and clinical trends in LNP-mRNA therapeutics in a broad range of treatments in ophthalmological conditions, cancer immunotherapy, gene editing, and rare-disease medicine. Particular attention is given to the translation and evolution of LNP-mRNA vaccines into a broader spectrum of therapeutics. We explore concerns in the aspects of inadequate extrahepatic targeting efficacy, elevated doses, safety concerns, and challenges of large-scale production procedures. This discussion may offer insights and perspectives on near- and long-term clinical development prospects for LNP-mRNA therapeutics.

Preclinical efficacy and pharmacokinetics of an RNA-encoded T cell-engaging bispecific antibody targeting human claudin 6

We present the preclinical pharmacology of BNT142, a lipid nanoparticle (LNP)-formulated RNA (RNA-LNP) encoding a T cell-engaging bispecific antibody that monovalently binds the T cell marker CD3 and bivalently binds claudin 6 (CLDN6), an oncofetal antigen that is absent from normal adult tissue but expressed on various solid tumors. Upon BNT142 RNA-LNP delivery in cell culture, mice, and cynomolgus monkeys, RNA is translated, followed by self-assembly into and secretion of the functional bispecific antibody RiboMab02.1. In vitro, RiboMab02.1 mediated CLDN6 target cell-specific activation and proliferation of T cells, and potent target cell killing. In mice and cynomolgus monkeys, intravenously administered BNT142 RNA-LNP maintained therapeutic serum concentrations of the encoded antibody. Concentrations of RNA-encoded RiboMab02.1 were maintained longer in circulation in mice than concentrations of directly injected, sequence-identical protein. Weekly injections of mice with BNT142 RNA-LNP in the 0.1- to 1-μg dose range were sufficient to eliminate CLDN6-positive subcutaneous human xenograft tumors and increase survival over controls. Tumor regression was associated with an influx of T cells and depletion of CLDN6-positive cells. BNT142 induced only transient and low cytokine production in CLDN6-positive tumor-bearing mice humanized with peripheral blood mononuclear cells (PBMCs). No signs of adverse effects from BNT142 RNA-LNP administration were observed in mice or cynomolgus monkeys. On the basis of these and other findings, a phase 1/2 first-in-human clinical trial has been initiated to assess the safety and preliminary efficacy of BNT142 RNA-LNP in patients with CLDN6-positive advanced solid tumors (NCT05262530).

The Platform Technology Approach to mRNA Product Development and Regulation

mRNA-lipid nanoparticle (LNP) medicinal products can be considered a platform technology because the development process is similar for different diseases and conditions, with similar noncoding mRNA sequences and lipid nanoparticles and essentially unchanged manufacturing and analytical methods often utilised for different products. It is critical not to lose the momentum built using the platform approach during the development, regulatory approval and rollout of vaccines for SARS-CoV-2 and its variants. This review proposes a set of modifications to existing regulatory requirements for mRNA products, based on a platform perspective for quality, manufacturing, preclinical, and clinical data. For the first time, we address development and potential regulatory requirements when the mRNA sequences and LNP composition vary in different products as well. In addition, we propose considerations for self-amplifying mRNA, individualised oncology mRNA products, and mRNA therapeutics. Providing a predictable development pathway for academic and commercial groups so that they can know in detail what product characterisation and data are required to develop a dossier for regulatory submission has many potential benefits. These include: reduced development and regulatory costs; faster consumer/patient access and more agile development of products in the face of pandemics; and for rare diseases where alternatives may not exist or to increase survival and the quality of life in cancer patients. Therefore, achieving consensus around platform approaches is both urgent and important. This approach with mRNA can be a template for similar platform frameworks for other therapeutics and vaccines to enable more efficient development and regulatory review.

Strategies to reduce the risks of mRNA drug and vaccine toxicity

mRNA formulated with lipid nanoparticles is a transformative technology that has enabled the rapid development and administration of billions of coronavirus disease 2019 (COVID-19) vaccine doses worldwide. However, avoiding unacceptable toxicity with mRNA drugs and vaccines presents challenges. Lipid nanoparticle structural components, production methods, route of administration and proteins produced from complexed mRNAs all present toxicity concerns. Here, we discuss these concerns, specifically how cell tropism and tissue distribution of mRNA and lipid nanoparticles can lead to toxicity, and their possible reactogenicity. We focus on adverse events from mRNA applications for protein replacement and gene editing therapies as well as vaccines, tracing common biochemical and cellular pathways. The potential and limitations of existing models and tools used to screen for on-target efficacy and de-risk off-target toxicity, including in vivo and next-generation in vitro models, are also discussed.

Rapid development of double-hit mRNA antibody cocktail against orthopoxviruses

The Orthopoxvirus genus, especially variola virus (VARV), monkeypox virus (MPXV), remains a significant public health threat worldwide. The development of therapeutic antibodies against orthopoxviruses is largely hampered by the high cost of antibody engineering and manufacturing processes. mRNA-encoded antibodies have emerged as a powerful and universal platform for rapid antibody production. Herein, by using the established lipid nanoparticle (LNP)-encapsulated mRNA platform, we constructed four mRNA combinations that encode monoclonal antibodies with broad neutralization activities against orthopoxviruses. In vivo characterization demonstrated that a single intravenous injection of each LNP-encapsulated mRNA antibody in mice resulted in the rapid production of neutralizing antibodies. More importantly, mRNA antibody treatments showed significant protection from weight loss and mortality in the vaccinia virus (VACV) lethal challenge mouse model, and a unique mRNA antibody cocktail, Mix2a, exhibited superior in vivo protection by targeting both intracellular mature virus (IMV)-form and extracellular enveloped virus (EEV)-form viruses. In summary, our results demonstrate the proof-of-concept production of orthopoxvirus antibodies via the LNP-mRNA platform, highlighting the great potential of tailored mRNA antibody combinations as a universal strategy to combat orthopoxvirus as well as other emerging viruses.

The development and technologies of RNA therapeutics

Since it was discovered for over 20 years ago, the potentiality of siRNAs in gene silencing in vitro and in vivo models has been recognized. Several studies in the new generation, molecular mechanisms, target attachment, and purification of RNA have supported the development of RNA therapeutics for a variety of applications. RNA therapeutics are growing rapidly with various platforms contributing to the standard of personalized medicine and rare disease treatment. Therefore, understanding the development and technologies of RNA therapeutics becomes a crucial point for new drug generation. Here, the primary purpose of this review is to provide a general view of six therapeutic categories that make up RNA-based therapeutic approaches, including RNA-target therapeutics, protein-targeted therapeutics, cellular reprogramming and tissues engineering, RNA-based protein replacement therapeutics, RNA-based genome editing, and RNA-based immunotherapies based on non-coding RNAs and coding RNA. Furthermore, we present an overview of the RNA strategies regarding viral approaches and nonviral approaches in designing a new generation of RNA technologies. The advantages and challenges of using RNA therapeutics are also discussed along with various approaches for RNA delivery. Therefore, this review is designed to provide updated reference evidence of RNA therapeutics in the battle against rare or difficult-to-treat diseases for researchers in this field.

A lung-selective delivery of mRNA encoding broadly neutralizing antibody against SARS-CoV-2 infection

The respiratory system, especially the lung, is the key site of pathological injury induced by SARS-CoV-2 infection. Given the low feasibility of targeted delivery of antibodies into the lungs by intravenous administration and the short half-life period of antibodies in the lungs by intranasal or aerosolized immunization, mRNA encoding broadly neutralizing antibodies with lung-targeting capability can perfectly provide high-titer antibodies in lungs to prevent the SARS-CoV-2 infection. Here, we firstly identify a human monoclonal antibody, 8-9D, with broad neutralizing potency against SARS-CoV-2 variants. The neutralization mechanism of this antibody is explained by the structural characteristics of 8-9D Fabs in complex with the Omicron BA.5 spike. In addition, we evaluate the efficacy of 8-9D using a safe and robust mRNA delivery platform and compare the performance of 8-9D when its mRNA is and is not selectively delivered to the lungs. The lung-selective delivery of the 8-9D mRNA enables the expression of neutralizing antibodies in the lungs which blocks the invasion of the virus, thus effectively protecting female K18-hACE2 transgenic mice from challenge with the Beta or Omicron BA.1 variant. Our work underscores the potential application of lung-selective mRNA antibodies in the prevention and treatment of infections caused by circulating SARS-CoV-2 variants.

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.

mRNA-based vaccines and therapeutics: an in-depth survey of current and upcoming clinical applications

mRNA-based drugs have tremendous potential as clinical treatments, however, a major challenge in realizing this drug class will promise to develop methods for safely delivering the bioactive agents with high efficiency and without activating the immune system. With regard to mRNA vaccines, researchers have modified the mRNA structure to enhance its stability and promote systemic tolerance of antigenic presentation in non-inflammatory contexts. Still, delivery of naked modified mRNAs is inefficient and results in low levels of antigen protein production. As such, lipid nanoparticles have been utilized to improve delivery and protect the mRNA cargo from extracellular degradation. This advance was a major milestone in the development of mRNA vaccines and dispelled skepticism about the potential of this technology to yield clinically approved medicines. Following the resounding success of mRNA vaccines for COVID-19, many other mRNA-based drugs have been proposed for the treatment of a variety of diseases. This review begins with a discussion of mRNA modifications and delivery vehicles, as well as the factors that influence administration routes. Then, we summarize the potential applications of mRNA-based drugs and discuss further key points pertaining to preclinical and clinical development of mRNA drugs targeting a wide range of diseases. Finally, we discuss the latest market trends and future applications of mRNA-based drugs.

Hit 'em Where It Hurts: Gram-Negative Bacterial Lipopolysaccharide as a Vaccine Target

Infections with antimicrobial-resistant (AMR) bacteria pose an increasing threat to the ability to perform surgical procedures, organ transplantation, and treat cancer among many other medical conditions. There are few new antimicrobials in the development pipeline. Vaccines against AMR Gram-negative bacteria may reduce the use of antimicrobials and prevent bacterial transmission. This review traces the origins of lipopolysaccharide (LPS)-based vaccines against Gram-negative bacteria, the role of O polysaccharides and LPS core regions as potential vaccine targets, the development of new vaccine technologies, and their application to vaccines in current development.

Recent Advances in Messenger Ribonucleic Acid (mRNA) Vaccines and Their Delivery Systems: A Review

Messenger ribonucleic acid (mRNA) was found as the intermediary that transfers genetic information from DNA to ribosomes for protein synthesis in 1961. The emergency use authorization of the two covid-19 mRNA vaccines, BNT162b2 and mRNA-1273, is a significant achievement in the history of vaccine development. Because they are generated in a cell-free environment using the in vitro transcription (IVT) process, mRNA vaccines are risk-free. Moreover, chemical modifications to the mRNA molecule, such as cap structures and changed nucleosides, have proved critical in overcoming immunogenicity concerns, achieving sustained stability, and achieving effective, accurate protein production in vivo. Several vaccine delivery strategies (including protamine, lipid nanoparticles (LNPs), polymers, nanoemulsions, and cell-based administration) were also optimized to load and transport RNA into the cytosol. LNPs, which are composed of a cationic or a pH-dependent ionizable lipid layer, a polyethylene glycol (PEG) component, phospholipids, and cholesterol, are the most advanced systems for delivering mRNA vaccines. Moreover, modifications of the four components that make up the LNPs showed to increase vaccine effectiveness and reduce side effects. Furthermore, the introduction of biodegradable lipids improved LNP biocompatibility. Furthermore, mRNA-based therapies are expected to be effective treatments for a variety of refractory conditions, including infectious diseases, metabolic genetic diseases, cancer, cardiovascular and cerebrovascular diseases. Therefore, the present review aims to provide the scientific community with up-to-date information on mRNA vaccines and their delivery systems.

Expanding the Reach of Monoclonal Antibodies: A Review of Synthetic Nucleic Acid Delivery in Immunotherapy

Harnessing the immune system to combat disease has revolutionized medical treatment. Monoclonal antibodies (mAbs), in particular, have emerged as important immunotherapeutic agents with clinical relevance in treating a wide range of diseases, including allergies, autoimmune diseases, neurodegenerative disorders, cancer, and infectious diseases. These mAbs are developed from naturally occurring antibodies and target specific epitopes of single molecules, minimizing off-target effects. Antibodies can also be designed to target particular pathogens or modulate immune function by activating or suppressing certain pathways. Despite their benefit for patients, the production and administration of monoclonal antibody therapeutics are laborious, costly, and time-consuming. Administration often requires inpatient stays and repeated dosing to maintain therapeutic levels, limiting their use in underserved populations and developing countries. Researchers are developing alternate methods to deliver monoclonal antibodies, including synthetic nucleic acid-based delivery, to overcome these limitations. These methods allow for in vivo production of monoclonal antibodies, which would significantly reduce costs and simplify administration logistics. This review explores new methods for monoclonal antibody delivery, including synthetic nucleic acids, and their potential to increase the accessibility and utility of life-saving treatments for several diseases.

Harnessing and bioprospecting botanical-based herbal medicines against potential drug targets for COVID-19: a review coupled molecular docking studies

Since the end of February 2020, the world has come to a standstill due to the virus SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2). Since then, the global scientific community has explored various remedies and treatments against this virus, including natural products that have always been a choice because of their many benefits. Various known phytochemicals are well documented for their antiviral properties. Research is being carried out to discover new natural plant products or existing ones as a treatment measure for this disease. The three important targets in this regard are-papain like protease (PLpro), spike protein, and 3 chymotrypsin like proteases (3CLpro). Various docking studies are also being elucidated to identify the phytochemicals that modulate crucial proteins of the virus. The paper is simultaneously a comprehensive review that covers recent advances in the domain of the effect of various botanically derived natural products as an alternative treatment approach against Coronavirus Disease 2019 (COVID-19). Furthermore, the docking analyses revealed that rutin (inhibitor of the major protease of SARS-CoV-2), gallocatechin (e.g., interacting with 03 hydrogen bonds with a spike-like protein), lycorine (showing the best binding affinity with amino acids GLN498, THR500 and GLY446 of the spike-like protein), and quercetrin (inhabiting at its residues ASP216, PHE219, and ILE259) are promising inhibitors of SARS‑CoV‑2.Communicated by Ramaswamy H. Sarma.

ncRNA-mediated ceRNA regulatory network: Transcriptomic insights into breast cancer progression and treatment strategies

With the rapid development of next-generation sequencing technology, several studies have shown that ncRNAs can act as competitive endogenous RNAs (ceRNAs) and are involved in various biological processes, such as proliferation, differentiation, apoptosis, and migration of breast cancer (BC) cells, and plays an important role in BC progression as a molecular target for its diagnosis, treatment, prognosis, and differentiation of subtypes and age groups of BC patients. Based on the description of ceRNA-related biological functions, this study screened and sorted the sequencing analysis and experimental verification conclusions of BC-related ceRNAs and found that the ncRNAs mediated ceRNA networks can promote the development of BC by promoting the expression of genes related to BC proliferation, drug resistance, and apoptosis, inducing the production of epithelial-mesenchymal transition (EMT) to promote metastasis and activating cancer-related signaling pathways.

Development and applications of mRNA treatment based on lipid nanoparticles

Nucleic acid-based therapies such as messenger RNA have the potential to revolutionize modern medicine and enhance the performance of existing pharmaceuticals. The key challenges of mRNA-based therapies are delivering the mRNA safely and effectively to the target tissues and cells and controlling its release from the delivery vehicle. Lipid nanoparticles (LNPs) have been widely studied as drug carriers and are considered to be state-of-the-art technology for nucleic acid delivery. In this review, we begin by presenting the advantages and mechanisms of action of mRNA therapeutics. Then we discuss the design of LNP platforms based on ionizable lipids and the applications of mRNA-LNP vaccines for prevention of infectious diseases and for treatment of cancer and various genetic diseases. Finally, we describe the challenges and future prospects of mRNA-LNP therapeutics.

The Landscape of Neutralizing Monoclonal Antibodies (nAbs) for Treatment and Prevention of COVID-19

Purpose

After nearly 3 years of the COVID-19 pandemic, even though a vast body of knowledge and products (including vaccines and treatments) have been developed and disseminated, the virus is still evolving and new variants arising. Consequently, thousands of lives continue to be lost. Neutralizing monoclonal antibodies (nAbs) are promising drugs that emerged to treat SARS-CoV-2. In the uncertainty of the current situation, there is the question of whether organizations should continue to invest in this technology. To help decision-making in scientifical and pharmaceutical organizations, it is of major importance to monitor the development of products and technologies. Therefore, the aim of this study is analyze the landscape of nAbs for COVID-19.

Methods

The scenario of 473 biotherapeutics focusing on nAbs was evaluated using foresight techniques and a review of literature. Data were obtained from structured and semi-structured databases and processed for treatment, cleaning, consistency, validation, and enrichment.

Results

We identified 227 nAbs and performed an extensive literature review of 16 nAbs in late clinical development, including development technologies, responses to variants of concern (VOCs), manufacturing, and clinical aspects.

Conclusions

Even though the emergence of new VOCs is a threat to the effectiveness of this treatment, demanding constant genomic surveillance, the use of nAbs to treat and prevent COVID-19 will probably continue to be relevant due to excellent safety profiles and the possibility of immediate immunity transfer, especially in patients showing inadequate immunological response to vaccination. Therefore, we suggest that organizations should keep investing in improvements in this technology.

mRNA-Based Approaches to Treating Liver Diseases

Diseases that affect the liver account for approximately 2 million deaths worldwide each year. The increasing prevalence of these diseases and the limited efficacy of current treatments are expected to stimulate substantial growth in the global market for therapeutics that target the liver. Currently, liver transplantation is the only curative option available for many liver diseases. Gene therapy represents a valuable approach to treatment. The liver plays a central role in a myriad of essential metabolic functions, making it an attractive organ for gene therapy; hepatocytes comprise the most relevant target. To date, viral vectors constitute the preferred approach to targeting hepatocytes with genes of therapeutic interest. Alternatively, mRNA-based therapy offers a number of comparative advantages. Clinical and preclinical studies undertaken to treat inherited metabolic diseases affecting the liver, cirrhosis and fibrosis, hepatocellular carcinoma, hepatitis B, and cytomegalovirus using lipid nanoparticle-encapsulated mRNAs that encode the therapeutic or antigenic protein of interest are discussed.

RNA in Cancer Immunotherapy: Unlocking the Potential of the Immune System

Recent advances in the manufacturing, modification, purification, and cellular delivery of ribonucleic acid (RNA) have enabled the development of RNA-based therapeutics for a broad array of applications. The approval of two SARS-CoV-2-targeting mRNA-based vaccines has highlighted the advances of this technology. Offering rapid and straightforward manufacturing, clinical safety, and versatility, this paves the way for RNA therapeutics to expand into cancer immunotherapy. Together with ongoing trials on RNA cancer vaccination and cellular therapy, RNA therapeutics could be introduced into clinical practice, possibly stewarding future personalized approaches. In the present review, we discuss recent advances in RNA-based immuno-oncology together with an update on ongoing clinical applications and their current challenges.

Nanoparticle-based immunotherapy of pancreatic cancer

Pancreatic cancer (PC) has a complex and unique tumor microenvironment (TME). Due to the physical barrier formed by the desmoplastic stroma, the delivery of drugs to the tumor tissue is limited. The TME also contributes to resistance to various immunotherapies such as cancer vaccines, chimeric antigen receptor T cell therapy and immune checkpoint inhibitors. Overcoming and/or modulating the TME is therefore one of the greatest challenges in developing new therapeutic strategies for PC. Nanoparticles have been successfully used as drug carriers and delivery systems in cancer therapy. Recent experimental and engineering developments in nanotechnology have resulted in increased drug delivery and improved immunotherapy for PC. In this review we discuss and analyze the current nanoparticle-based immunotherapy approaches that are at the verge of clinical application. Particularly, we focus on nanoparticle-based delivery systems that improve the effectiveness of PC immunotherapy. We also highlight current clinical research that will help to develop new therapeutic strategies for PC and especially targeted immunotherapies based on immune checkpoint inhibitors.

Therapeutic Potential of Intrabodies for Cancer Immunotherapy: Current Status and Future Directions

Tumor cells are characterized by overexpressed tumor-associated antigens or mutated neoantigens, which are expressed on the cell surface or intracellularly. One strategy of cancer immunotherapy is to target cell-surface-expressed tumor-associated antigens (TAAs) with therapeutic antibodies. For targeting TAAs or neoantigens, adoptive T-cell therapies with activated autologous T cells from cancer patients transduced with novel recombinant TCRs or chimeric antigen receptors have been successfully applied. Many TAAs and most neoantigens are expressed in the cytoplasm or nucleus of tumor cells. As alternative to adoptive T-cell therapy, the mRNA of intracellular tumor antigens can be depleted by RNAi, the corresponding genes or proteins deleted by CRISPR-Cas or inactivated by kinase inhibitors or by intrabodies, respectively. Intrabodies are suitable to knockdown TAAs and neoantigens without off-target effects. RNA sequencing and proteome analysis of single tumor cells combined with computational methods is bringing forward the identification of new neoantigens for the selection of anti-cancer intrabodies, which can be easily performed using phage display antibody repertoires. For specifically delivering intrabodies into tumor cells, the usage of new capsid-modified adeno-associated viruses and lipid nanoparticles coupled with specific ligands to cell surface receptors can be used and might bring cancer intrabodies into the clinic.

A Single Dose of Anti-HBsAg Antibody-Encoding mRNA-LNPs Suppressed HBsAg Expression: a Potential Cure of Chronic Hepatitis B Virus Infection

It is the first time that mRNA-LNPs have been used to express anti-HBsAg antibodies (G12-scFv, G12-scFv-Fc, and G12-IgG). G12-scFv-Fc- and G12-IgG-encoding mRNA-LNPs exerted a sustained effect on HBsAg serum clearance in the adeno-associated virus (AAV)/HBV mouse model with persistent HBsAg expression.

mRNA-based therapeutics: powerful and versatile tools to combat diseases

The therapeutic use of messenger RNA (mRNA) has fueled great hope to combat a wide range of incurable diseases. Recent rapid advances in biotechnology and molecular medicine have enabled the production of almost any functional protein/peptide in the human body by introducing mRNA as a vaccine or therapeutic agent. This represents a rising precision medicine field with great promise for preventing and treating many intractable or genetic diseases. In addition, in vitro transcribed mRNA has achieved programmed production, which is more effective, faster in design and production, as well as more flexible and cost-effective than conventional approaches that may offer. Based on these extraordinary advantages, mRNA vaccines have the characteristics of the swiftest response to large-scale outbreaks of infectious diseases, such as the currently devastating pandemic COVID-19. It has always been the scientists’ desire to improve the stability, immunogenicity, translation efficiency, and delivery system to achieve efficient and safe delivery of mRNA. Excitingly, these scientific dreams have gradually been realized with the rapid, amazing achievements of molecular biology, RNA technology, vaccinology, and nanotechnology. In this review, we comprehensively describe mRNA-based therapeutics, including their principles, manufacture, application, effects, and shortcomings. We also highlight the importance of mRNA optimization and delivery systems in successful mRNA therapeutics and discuss the key challenges and opportunities in developing these tools into powerful and versatile tools to combat many genetic, infectious, cancer, and other refractory diseases.

Nucleic acid vaccines and CpG oligodeoxynucleotides for allergen immunotherapy

PURPOSE OF REVIEW

Molecular forms of allergen-specific immunotherapy (AIT) are continuously emerging to improve the efficacy of the treatment, to shorten the duration of protocols and to prevent any side effects. The present review covers the recent progress in the development of AIT based on nucleic acid encoding allergens or CpG oligodeoxynucleotides (CpG-ODN).

RECENT FINDINGS

Therapeutic vaccinations with plasmid deoxyribonucleic acid (DNA) encoding major shrimp Met e 1 or insect For t 2 allergen were effective for the treatment of food or insect bite allergy in respective animal models. DNA expressing hypoallergenic shrimp tropomyosin activated Foxp3+ T regulatory (Treg) cells whereas DNA encoding For t 2 down-regulated the expression of pruritus-inducing IL-31. Co-administrations of major cat allergen Fel d 1 with high doses of CpG-ODN reduced Th2 airway inflammation through tolerance induction mediated by GATA3+ Foxp3hi Treg cells as well as early anti-inflammatory TNF/TNFR2 signaling cascade. Non-canonical CpG-ODN derived from Cryptococcus neoformans as well as methylated CpG sites present in the genomic DNA from Bifidobacterium infantis mediated Th1 or Treg cell differentiation respectively.

SUMMARY

Recent studies on plasmid DNA encoding allergens evidenced their therapeutic potential for the treatment of food allergy and atopic dermatitis. Unmethylated or methylated CpG-ODNs were shown to activate dose-dependent Treg/Th1 responses. Large clinical trials need to be conducted to confirm these promising preclinical data. Moreover, tremendous success of messenger ribonucleic acid (mRNA) vaccines against severe acute respiratory syndrome coronavirus 2 must encourage as well the re-exploration of mRNA vaccine platform for innovative AIT.

Antibody-Based Immunotoxins for Colorectal Cancer Therapy

Monoclonal antibodies (mAbs) are included among the treatment options for advanced colorectal cancer (CRC). However, while these mAbs effectively target cancer cells, they may have limited clinical activity. A strategy to improve their therapeutic potential is arming them with a toxic payload. Immunotoxins (ITX) combining the cell-killing ability of a toxin with the specificity of a mAb constitute a promising strategy for CRC therapy. However, several important challenges in optimizing ITX remain, including suboptimal pharmacokinetics and especially the immunogenicity of the toxin moiety. Nonetheless, ongoing research is working to solve these limitations and expand CRC patients' therapeutic armory. In this review, we provide a comprehensive overview of targets and toxins employed in the design of ITX for CRC and highlight a wide selection of ITX tested in CRC patients as well as preclinical candidates.

Targeting the Inside of Cells with Biologicals: Chemicals as a Delivery Strategy

Delivering macromolecules into the cytosol or nucleus is possible in vitro for DNA, RNA and proteins, but translation for clinical use has been limited. Therapeutic delivery of macromolecules into cells requires overcoming substantially higher barriers compared to the use of small molecule drugs or proteins in the extracellular space. Breakthroughs like DNA delivery for approved gene therapies and RNA delivery for silencing of genes (patisiran, ONPATTRO^®, Alnylam Pharmaceuticals, Cambridge, MA, USA) or for vaccination such as the RNA-based coronavirus disease 2019 (COVID-19) vaccines demonstrated the feasibility of using macromolecules inside cells for therapy. Chemical carriers are part of the reason why these novel RNA-based therapeutics possess sufficient efficacy for their clinical application. A clear advantage of synthetic chemicals as carriers for macromolecule delivery is their favourable properties with respect to production and storage compared to more bioinspired vehicles like viral vectors or more complex drugs like cellular therapies. If biologicals can be applied to intracellular targets, the druggable space is substantially broadened by circumventing the limited utility of small molecules for blocking protein–protein interactions and the limitation of protein-based drugs to the extracellular space. An in depth understanding of the macromolecular cargo types, carrier types and the cell biology of delivery is crucial for optimal application and further development of biologicals inside cells. Basic mechanistic principles of the molecular and cell biological aspects of cytosolic/nuclear delivery of macromolecules, with particular consideration of protein delivery, are reviewed here. The efficiency of macromolecule delivery and applications in research and therapy are highlighted.

Engineered mRNA and the Rise of Next-Generation Antibodies

Monoclonal antibodies are widely used as therapeutic agents in medicine. However, clinical-grade proteins require sophisticated technologies and are extremely expensive to produce, resulting in long lead times and high costs. The use of gene transfer methods for in vivo secretion of therapeutic antibodies could circumvent problems related to large-scale production and purification and offer additional benefits by achieving sustained concentrations of therapeutic antibodies, which is particularly relevant to short-lived antibody fragments and next-generation, Fc-free, multispecific antibodies. In recent years, the use of engineered mRNA-based gene delivery has significantly increased in different therapeutic areas because of the advantages it possesses over traditional gene delivery platforms. The application of synthetic mRNA will allow for the avoidance of manufacturing problems associated with recombinant proteins and could be instrumental in consolidating regulatory approvals for next-generation therapeutic antibodies.

mRNA Innovates the Vaccine Field

Development of new vaccine modalities is a critical need to address many of the shortcomings of traditional platforms such as the lack of sufficient efficacy against certain pathogens or cancer; difficulties with production; or, in some cases, safety issues [...].

An Updated Review of SARS-CoV-2 Vaccines and the Importance of Effective Vaccination Programs in Pandemic Times

Since the worldwide COVID-19 pandemic was declared a year ago, the search for vaccines has become the top priority in order to restore normalcy after 2.5 million deaths worldwide, overloaded sanitary systems, and a huge economic burden. Vaccine development has represented a step towards the desired herd immunity in a short period of time, owing to a high level of investment, the focus of researchers, and the urge for the authorization of the faster administration of vaccines. Nevertheless, this objective may only be achieved by pursuing effective strategies and policies in various countries worldwide. In the present review, some aspects involved in accomplishing a successful vaccination program are addressed, in addition to the importance of vaccination in a pandemic in the face of unwillingness, conspiracy theories, or a lack of information among the public. Moreover, we provide some updated points related to the landscape of the clinical development of vaccine candidates, specifically, the top five vaccines that are already being assessed in Phase IV clinical trials (BNT162b2, mRNA-1273, AZD1222, Ad26.COV2.S, and CoronaVac).

Path to Success and Future Impact of Nucleic Acid Vaccines: DNA and mRNA

The rapid development of mRNA vaccines for COVID-19 has both astonished the world and raised concerns about their safety, perhaps because many people do not realize the decades’ long efforts for nucleic acid vaccines, both mRNA and DNA vaccines, including the licensure of several veterinary DNA vaccines. This manuscript traces the milestones for nucleic acid vaccine research and development (R&D), with a focus on the immune and safety issues they both raised and answered. The characteristics of the two entities are compared, demonstrating the similarities and differences between them, the advantages and disadvantages, which might lead toward using one or the other technology for different indications. In addition, as the SARS-CoV-2 pandemic has once again highlighted the importance of One Health, that is, the interactions between animal and human pathogens, focus will also be given to how DNA vaccine utilization and studies both in large domestic animals and in wildlife pave the way for more integrated approaches for vaccines to respond quickly to, and prevent, the global impacts of emerging diseases.