Generation of effector memory T cell-based mucosal and systemic immunity with pulmonary nanoparticle vaccination

Microbiome miracles and their pioneering advances and future frontiers in cardiovascular disease

Cardiovascular diseases (CVDs) represent a significant global health challenge, underscoring the need for innovative approaches to prevention and treatment. Recent years have seen a surge in interest in unraveling the complex relationship between the gut microbiome and cardiovascular health. This article delves into current research on the composition, diversity, and impact of the gut microbiome on CVD development. Recent advancements have elucidated the profound influence of the gut microbiome on disease progression, particularly through key mediators like Trimethylamine-N-oxide (TMAO) and other microbial metabolites. Understanding these mechanisms reveals promising therapeutic targets, including interventions aimed at modulating the gut microbiome's interaction with the immune system and its contribution to endothelial dysfunction. Harnessing this understanding, personalized medicine strategies tailored to individuals' gut microbiome profiles offer innovative avenues for reducing cardiovascular risk. As research in this field continues to evolve, there is vast potential for transformative advancements in cardiovascular medicine, paving the way for precision prevention and treatment strategies to address this global health challenge.

Mucosal delivery of a prefusogenic-F, glycoprotein, and matrix proteins-based virus-like particle respiratory syncytial virus vaccine induces protective immunity as evidenced by challenge studies in mice

RSV infection remains a serious threat to the children all over the world, especially, in the low-middle income countries. Vaccine delivery via the mucosa holds great potential for inducing local immune responses in the respiratory tract. Previously, we reported the development of highly immunogenic RSV virus-like-particles (RSV-VLPs) based on the conformationally stable prefusogenic-F protein (preFg), glycoprotein and matrix protein. Here, to explore whether mucosal delivery of RSV-VLPs is an effective strategy to induce RSV-specific mucosal and systemic immunity, RSV-VLPs were administered via the nasal, sublingual and pulmonary routes to BALB/c mice. The results demonstrate that immunization with the VLPs via the mucosal routes induced minimal mucosal response and yet facilitated modest levels of serum IgG antibodies, enhanced T cell responses and the expression of the lung-homing marker CXCR3 on splenocytes. Immunization with VLPs via all three mucosal routes provided protection against RSV challenge with no signs of RSV induced pathology.

Understanding Mucosal Physiology and Rationale of Formulation Design for Improved Mucosal Immunity

The oral and nasal cavities serve as critical gateways for infectious pathogens, with microorganisms primarily gaining entry through these routes. Our first line of defense against these invaders is the mucosal membrane, a protective barrier that shields the body's internal systems from infection while also contributing to vital functions like air and nutrient intake. One of the key features of this mucosal barrier is its ability to protect the physiological system from pathogens. Additionally, mucosal tolerance plays a crucial role in maintaining homeostasis by regulating the pH and water balance within the body. Recognizing the importance of the mucosal barrier, researchers have developed various mucosal formulations to enhance the immune response. Mucosal vaccines, for example, deliver antigens directly to mucosal tissues, triggering local immune stimulation and ultimately inducing systemic immunity. Studies have shown that lipid-based formulations such as liposomes and virosomes can effectively elicit both local and systemic immune responses. Furthermore, mucoadhesive polymeric particles, with their prolonged delivery to target sites, have demonstrated an enhanced immune response. This Review delves into the critical role of material selection and delivery approaches in optimizing mucosal immunity.

Immunomodulatory and immune-toxicological role of nanoparticles: Potential therapeutic applications

Nowadays, Nanoparticle-based immunotherapeutic research has invoked global interest due to their unique properties. The immune system is a shielding structure that defends living things from external threats. Before the use of any materials in drug design, it is essential to study the immunological response to avoid triggering undesirable immune responses in the body. This review tries to summarize the properties, various applications, and immunotherapeutic aspects of NP-induced immunomodulation relating to therapeutic development and toxicity in human health. The role of NPs in the immune system and their modulatory functions, resulting in immunosuppression or immunostimulation, exerts benefits or dangers depending on their compositions, sizes, surface chemistry, and so forth. After NPs enter into the body, they can interact with body fluid exposing, them to different body proteins to form protein corona particles and other bio-molecules (DNA, RNA, sugars, etc.), which may alter their bioactivity. Phagocytes are the first immune cells that can interact with foreign materials including nanoparticles. Immunostimulation and immunosuppression operate in two distinct manners. Overall, functionalized nanocarriers optimized various therapeutic implications by stimulating the host immune system and regulating the tranquility of the host immune system. Among others, toxicity and bio-clearance of nanomaterials are always prime concerns at the preclinical and clinical stages before final approval. The interaction of nanoparticles with immune cells causes direct cell damage via apoptosis and necroses as well as immune signaling pathways also become influenced.

Genetically engineered membrane-based nanoengagers for immunotherapy of pancreatic cancer

Modulating macrophages presents a promising avenue in tumor immunotherapy. However, tumor cells have evolved mechanisms to evade macrophage activation and phagocytosis. Herein, we introduced a bispecific antibody-based nanoengager to facilitate the recognition and phagocytosis of tumor cells by macrophages. Specifically, we genetically engineered two single chain variable fragments (scFv) onto cell membrane: anti-CD40 scFv for engaging with macrophages and anti-Claudin18.2 (CLDN18.2) scFv for interacting with tumor cells. These nanoengagers were further constructed by coating scFv-anchored membrane into PLGA nanoparticle core. Our developed nanoengagers significantly boosted immune responses, including increased recognition and phagocytosis of tumor cells by macrophages, enhanced activation and antigen presentation, and elevated cytotoxic T lymphocyte activity. These combined benefits resulted in enhancing antitumor efficacy against highly aggressive "cold" pancreatic cancer. Overall, this study offers a versatile nanoengager design for immunotherapy, achieved through genetically engineering to incorporate antibody-anchored membrane.

Harnessing Biomaterials to Amplify Immunity in Aged Mice through T Memory Stem Cells

The durability of a protective immune response generated by a vaccine depends on its ability to induce long-term T cell immunity, which tends to decline in aging populations. The longest protection appears to arise from T memory stem cells (TMSCs) that confer high expandability and effector functions when challenged. Here we engineered artificial antigen presenting cells (aAPC) with optimized size, stiffness and activation signals to induce human and mouse CD8+ TMSCs in vitro. This platform was optimized as a vaccine booster of TMSCs (Vax-T) with prolonged release of small-molecule blockade of the glycogen synthase kinase-3β together with target antigens. By using SARS-CoV-2 antigen as a model, we show that a single injection of Vax-T induces durable antigen-specific CD8+ TMSCs in young and aged mice, and generates humoral responses at a level stronger than or similar to soluble vaccines. This Vax-T approach can boost long-term immunity to fight infectious diseases, cancer, and other diseases.

Engineering cancer cell membranes with endogenously upregulated HSP70 as a reinforced antigenic repertoire for the construction of material-free prophylactic cancer vaccines

Immune cells distinguish cancer cells mainly relying on their membrane-membrane communication. The major challenge of cancer vaccines exists in difficult identification of cancer neoantigens and poor understanding over immune recognition mechanisms against cancer cells, particularly the combination among multiple antigens and the cooperation between antigens and immune-associated proteins. We exploit cancer cell membranes as the whole cancer antigen repertoire and reinforce its immunogenicity by cellular engineering to modulate the cytomembrane's immune-associated functions. This study reports a vaccine platform based on radiation-engineered cancer cells, of which the membrane HSP70 protein as the immune chaperon/traitor is endogenously upregulated. The resulting positive influences are shown to cover immunogenic steps occurring in antigen-presenting cells, including the uptake and the cross-presentation of the cancer antigens, thus amplifying cancer-specific immunogenicity. Membrane vaccines offer chances to introduce desired metal ions through membrane-metal complexation. Using Mn2+ ion as the costimulatory interferon genes agonist, immune activity is enhanced to further boost adaptive cancer immunogenicity. Results have evidenced that this artificially engineered membrane vaccine with favorable bio-safety could considerably reduce tumorigenicity and inhibit tumor growth. This study provides a universally applicable and facilely available cancer vaccine platform by artificial engineering of cancer cells to inherit and amplify the natural merits of cancer cell membranes. STATEMENT OF SIGNIFICANCE: The major challenge of cancer vaccines exists in difficult identification of cancer neoantigens and poor understanding over immune recognition mechanisms against cancer cells, particularly the combination among multiple antigens and the cooperation between antigens and immune-associated proteins. Cancer cell membrane presents superior advantages as the whole cancer antigen repertoire, including the reported and the unidentified antigens, but its immunogenicity is far from satisfactory. Cellular engineering approaches offer chances to endogenously modulate the immune-associated functions of cell membranes. Such a reinforced vaccine based on the engineered cancer cell membranes matches better the natural immune recognition pathway than the conventional vaccines.

Memory T Cells in the Immunoprevention of Cancer: A Switch from Therapeutic to Prophylactic Approaches

Cancer immunoprevention, the engagement of the immune system to prevent cancer, is largely overshadowed by therapeutic approaches to treating cancer after detection. Vaccines or, alternatively, the utilization of genetically engineered memory T cells could be methods of engaging and creating cancer-specific T cells with superb memory, lenient activation requirements, potent antitumor cytotoxicity, tumor surveillance, and resilience against immunosuppressive factors in the tumor microenvironment. In this review we analyze memory T cell subtypes based on their potential utility in cancer immunoprevention with regard to longevity, localization, activation requirements, and efficacy in fighting cancers. A particular focus is on how both tissue-resident memory T cells and stem memory T cells could be promising subtypes for engaging in immunoprevention.

Advances in nanomedicines for lymphatic imaging and therapy

Lymph nodes play a pivotal role in tumor progression as key components of the lymphatic system. However, the unique physiological structure of lymph nodes has traditionally constrained the drug delivery efficiency. Excitingly, nanomedicines have shown tremendous advantages in lymph node-specific delivery, enabling distinct recognition and diagnosis of lymph nodes, and hence laying the foundation for efficient tumor therapies. In this review, we comprehensively discuss the key factors affecting the specific enrichment of nanomedicines in lymph nodes, and systematically summarize nanomedicines for precise lymph node drug delivery and therapeutic application, including the lymphatic diagnosis and treatment nanodrugs and lymph node specific imaging and identification system. Notably, we delve into the critical challenges and considerations currently facing lymphatic nanomedicines, and futher propose effective strategies to address these issues. This review encapsulates recent findings, clinical applications, and future prospects for designing effective nanocarriers for lymphatic system targeting, with potential implications for improving cancer treatment strategies.

Polymer nanoparticles deliver mRNA to the lung for mucosal vaccination

An inhalable platform for messenger RNA (mRNA) therapeutics would enable minimally invasive and lung-targeted delivery for a host of pulmonary diseases. Development of lung-targeted mRNA therapeutics has been limited by poor transfection efficiency and risk of vehicle-induced pathology. Here, we report an inhalable polymer-based vehicle for delivery of therapeutic mRNAs to the lung. We optimized biodegradable poly(amine-co-ester) (PACE) polyplexes for mRNA delivery using end-group modifications and polyethylene glycol. These polyplexes achieved high transfection of mRNA throughout the lung, particularly in epithelial and antigen-presenting cells. We applied this technology to develop a mucosal vaccine for severe acute respiratory syndrome coronavirus 2 and found that intranasal vaccination with spike protein-encoding mRNA polyplexes induced potent cellular and humoral adaptive immunity and protected susceptible mice from lethal viral challenge. Together, these results demonstrate the translational potential of PACE polyplexes for therapeutic delivery of mRNA to the lungs.

Inhaled drug delivery for the targeted treatment of asthma

Asthma is a chronic lung disease affecting millions worldwide. While classically acknowledged to result from allergen-driven type 2 inflammatory responses leading to IgE and cytokine production and the influx of immune cells such as mast cells and eosinophils, the wide range in asthmatic pathobiological subtypes lead to highly variable responses to anti-inflammatory therapies. Thus, there is a need to develop patient-specific therapies capable of addressing the full spectrum of asthmatic lung disease. Moreover, delivery of targeted treatments for asthma directly to the lung may help to maximize therapeutic benefit, but challenges remain in design of effective formulations for the inhaled route. In this review, we discuss the current understanding of asthmatic disease progression as well as genetic and epigenetic disease modifiers associated with asthma severity and exacerbation of disease. We also overview the limitations of clinically available treatments for asthma and discuss pre-clinical models of asthma used to evaluate new therapies. Based on the shortcomings of existing treatments, we highlight recent advances and new approaches to treat asthma via inhalation for monoclonal antibody delivery, mucolytic therapy to target airway mucus hypersecretion and gene therapies to address underlying drivers of disease. Finally, we conclude with discussion on the prospects for an inhaled vaccine to prevent asthma.

Long-acting vaccine delivery systems

Bolus vaccines are often administered multiple times due to rapid clearance and reduced transportation to draining lymph nodes resulting in inadequate activation of T and B lymphocytes. In order to achieve adaptive immunity, prolonged exposure of antigens to these immune cells is crucial. Recent research has been focusing on developing long-acting biomaterial-based vaccine delivery systems, which can modulate the release of encapsulated antigens or epitopes to facilitate enhanced antigen presentation in lymph nodes and subsequently achieve robust T and B cell responses. Over the past few years, various polymers and lipids have been extensively explored to develop effective biomaterial-based vaccine strategies. The article reviews relevant polymer and lipid-based strategies used to prepare long-acting vaccine carriers and discusses their results concerning immune responses.

Nanoparticles as a Delivery System of Antigens for the Development of an Effective Vaccine against Toxoplasma gondii

Nanoparticles include particles ranging in size from nanometers to micrometers, whose physicochemical characteristics are optimized to make them appropriate delivery vehicles for drugs or immunogens important in the fight and/or prevention of infectious diseases. There has been a rise in the use of nanoparticles in preventive vaccine formulations as immunostimulatory adjuvants, and as vehicles for immunogen delivery to target immune cells. Toxoplasma is important worldwide, and may cause human toxoplasmosis. In immunocompetent hosts, infection is usually asymptomatic, but in immunocompromised patients it can cause serious neurological and ocular consequences, such as encephalitis and retinochoroiditis. Primary infection during pregnancy may cause abortion or congenital toxoplasmosis. Currently, there is no effective human vaccine against this disease. Evidence has emerged from several experimental studies testing nanovaccines showing them to be promising tools in the prevention of experimental toxoplasmosis. For the present study, a literature review was carried out on articles published over the last 10 years through the PubMed database, pertaining to in vivo experimental models of T. gondii infection where nanovaccines were tested and protection and immune responses evaluated. This review aims to highlight the way forward in the search for an effective vaccine for toxoplasmosis.

Nano-vaccines for gene delivery against HIV-1 infection

INTRODUCTION

Over the last four decades, human immunodeficiency virus type 1 (HIV-1) infection has been a major public health concern. It is acknowledged that an effective vaccine remains the best hope for eliminating the HIV-1 pandemic. The prophylaxis of HIV-1 infection remains a central theme because of the absence of an available HIV-1 vaccine. The incapability of conventional delivery strategies to induce potent immunity is a crucial task to overcome and ultimately lead to a major obstacle in HIV-1 vaccine research.

AREAS COVERED

The literature search was conducted in the following databases: PubMed, Web of Science, and Embase. Nano-platforms based vaccines have proven prophylaxis of various diseases for effectively activating the immune system. Nano-vaccines, including non-viral and viral vectored nano-vaccines, are in a position to improve the effectiveness of HIV-1 antigen delivery and enhance the innate and adaptive immune responses against HIV-1. Compared to traditional vaccination strategies, genetic immunization can elicit a long-term immune response to provide protective immunity for HIV-1 prevention.

EXPERT OPINION

The research progress on nano-vaccines for gene delivery against HIV-1 was discussed. The vaccine strategies based on nano-platforms that are being applied to stimulate effective HIV-1-specific cellular and humoral immune responses were particularly emphasized.

Advanced implications of nanotechnology in disease control and environmental perspectives

Nanotechnology encompasses a wide range of devices derived from biology, engineering, chemistry, and physics, and this scientific field is composed of great collaboration among researchers from several fields. It has diverse implications notably smart sensing technologies, effective disease diagnosis, and sometimes used in treatment. In medical science, the implications of nanotechnology include the development of elements and devices that interact with the body at subcellular (i.e., molecular) levels exhibiting high sensitivity and specificity. There is a plethora of new chances for medical science and disease treatment to be discovered and exploited in the rapidly developing field of nanotechnology. In different sectors, nanomaterials are used just because of their special characteristics. Their large surface area of them enables higher reactivity with greater efficiency. Furthermore, special surface chemistry is displayed by nanomaterials which compare to conventional materials and facilitate the nanomaterials to decrease pollutants efficiently. Recently, nanomaterials are used in some countries to reduce the levels of contaminants in water, air, and soil. Moreover, nanomaterials are used in the cosmetics and medical industry, and it develops the drug discovery (DD) system. Among a huge number of nanomaterials, Cu, Ag, TiO₂, ZnO, Fe₃O₄, and carbon nanotubes (CNTs) are extensively used in different industries for various purposes. This extensive review study has introduced the major scientific and technical features of nanotechnology, as well as some possible clinical applications and positive feedback in environmental waste management and drug delivery systems.

The development of highly dense highly protected surfactant ionizable lipid RNA loaded nanoparticles

The long quest for efficient drug administration has been looking for a universal carrier that can precisely transport traditional drugs, new genomic and proteic therapeutic agents. Today, researchers have found conditions to overcome the two main drug delivery dilemmas. On the one side, the versatility of the vehicle to efficiently load, protect and transport the drug and then release it at the target place. On the other hand, the questions related to the degree of PEGylation which are needed to avoid nanoparticle (NP) aggregation and opsonization while preventing cellular uptake. The development of different kinds of lipidic drug delivery vehicles and particles has resulted in the development of ionizable lipid nanoparticles (iLNPs), which can overcome most of the typical drug delivery problems. Proof of their success is the late approval and massive administration as the prophylactic vaccine for SARS-CoV-2. These ILNPs are built by electrostatic aggregation of surfactants, the therapeutic agent, and lipids that self-segregate from an aqueous solution, forming nanoparticles stabilized with lipid polymers, such as PEG. These vehicles overcome previous limitations such as low loading and high toxicity, likely thanks to low charge at the working pH and reduced size, and their entry into the cells via endocytosis rather than membrane perforation or fusion, always associated with higher toxicity. We herein revise their primary features, synthetic methods to prepare and characterize them, pharmacokinetic (administration, distribution, metabolization and excretion) aspects, and biodistribution and fate. Owing to their advantages, iLNPs are potential drug delivery systems to improve the management of various diseases and widely available for clinical use.

Tissue-Targeted Drug Delivery Strategies to Promote Antigen-Specific Immune Tolerance

During autoimmunity or organ transplant rejection, the immune system attacks host or transplanted tissue, causing debilitating inflammation for millions of patients. There is no cure for most of these diseases. Further, available therapies modulate inflammation through nonspecific pathways, reducing symptoms but also compromising patients' ability to mount healthy immune responses. Recent preclinical advances to regulate immune dysfunction with vaccine-like antigen specificity reveal exciting opportunities to address the root cause of autoimmune diseases and transplant rejection. Several of these therapies are currently undergoing clinical trials, underscoring the promise of antigen-specific tolerance. Achieving antigen-specific tolerance requires precision and often combinatorial delivery of antigen, cytokines, small molecule drugs, and other immunomodulators. This can be facilitated by biomaterial technologies, which can be engineered to orient and display immunological cues, protect against degradation, and selectively deliver signals to specific tissues or cell populations. In this review, some key immune cell populations involved in autoimmunity and healthy immune tolerance are described. Opportunities for drug delivery to immunological organs are discussed, where specialized tissue-resident immune cells can be programmed to respond in unique ways toward antigens. Finally, cell- and biomaterial-based therapies to induce antigen-specific immune tolerance that are currently undergoing clinical trials are highlighted.

Challenging the fundamental conjectures in nanoparticle drug delivery for chemotherapy treatment of solid cancers

Nanomedicines for cancer treatment have been studied extensively over the last few decades. Yet, only five anticancer nanomedicines have received approvals from the United States Food and Drug Administration (FDA) for treating solid tumors. This drastic mismatch between effort and return calls into question the basic understanding of this field. Various viewpoints on nanomedicines have been presented regarding their potentials and inefficiencies. However, the underlying logics of nanomedicine research and its inadequate translation to the successful use in the clinic have not been thoroughly examined. Tumor-targeted drug delivery was used to understand the shortfalls of the nanomedicine field in general. The concept of tumor-targeted drug delivery by nanomedicine has been based on two conjectures: (i) increased drug delivery to tumors provides better efficacy, and (ii) decreased drug delivery to healthy organs results in fewer side effects. The clinical evidence gathered from the literature indicates that nanomedicines bearing classic chemotherapeutic drugs, such as Dox, cis-Pt, CPT and PTX, have already reached the maximum drug delivery limit to solid tumors in humans. Still, the anticancer efficacy and safety remain unchanged despite the increased tumor accumulation. Thus, it is understandable to see few nanomedicine-based formulations approved by the FDA. The examination of FDA-approved nanomedicine formulations indicates that their approvals were not based on the improved delivery to tumors but mostly on changes in dose-limiting toxicity unique to each drug. This comprehensive analysis of the fundamentals of anticancer nanomedicines is designed to provide an accurate picture of the field's underlying false conjectures, hopefully, thereby accelerating the future clinical translations of many formulations under research.

Role of Nanomaterials in COVID-19 Prevention, Diagnostics, Therapeutics, and Vaccine Development

Facing the deadly pandemic caused by the SARS-CoV-2 virus all over the globe, it is crucial to devote efforts to fighting and preventing this infectious virus. Nanomaterials have gained much attention after the approval of lipid nanoparticle-based COVID-19 vaccines by the United States Food and Drug Administration (USFDA). In light of increasing demands for utilizing nanomaterials in the management of COVID-19, this comprehensive review focuses on the role of nanomaterials in the prevention, diagnostics, therapeutics, and vaccine development of COVID-19. First, we highlight the variety of nanomaterials usage in the prevention of COVID-19. We discuss the advantages of nanomaterials as well as their uses in the production of diagnostic tools and treatment methods. Finally, we review the role of nanomaterials in COVID-19 vaccine development. This review offers direction for creating products based on nanomaterials to combat COVID-19.

Immunomodulation, Toxicity, and Therapeutic Potential of Nanoparticles

Altered immune responses associated with human disease conditions, such as inflammatory and infectious diseases, cancers, and autoimmune diseases, are among the primary causes of morbidity across the world. A wealth of studies has demonstrated the efficiency of nanoparticles (NPs)-based immunotherapy strategies in different laboratory model systems. Nanoscale dimensions (<100 nm) enable NPs to have increased surface area to volume ratio, surface charge, and reactivity. Physicochemical properties along with the shapes, sizes, and elasticity influence the immunomodulatory response induced by NPs. In recent years, NPs-based immunotherapy strategies have attained significant focus in the context of cancers and autoimmune diseases. This rapidly growing field of nanomedicine has already introduced ~50 nanotherapeutics in clinical practices. Parallel to wide industrial applications of NPs, studies have raised concerns about their potential threat to the environment and human health. In past decades, a wealth of in vivo and in vitro studies has demonstrated the immunotoxicity potential of various NPs. Given that the number of engineered/designed NPs in biomedical applications is continuing to increase, it is pertinent to establish the toxicity profile for their safe and intelligent use in biomedical applications. The review is intended to summarize the NPs-induced immunomodulation pertaining to toxicity and therapeutic development in human health.

Functional Nanoparticles for Enhanced Cancer Therapy

Cancer is the leading cause of death in people worldwide. The conventional therapeutic approach is mainly based on chemotherapy, which has a series of side effects. Compared with traditional chemotherapy drugs, nanoparticle-based delivery of anti-cancer drugs possesses a few attractive features. The application of nanotechnology in an interdisciplinary manner in the biomedical field has led to functional nanoparticles achieving much progress in cancer therapy. Nanoparticles have been involved in the diagnosis and targeted and personalized treatment of cancer. For example, different nano-drug strategies, including endogenous and exogenous stimuli-responsive, surface conjugation, and macromolecular encapsulation for nano-drug systems, have successfully prevented tumor procession. The future for functional nanoparticles is bright and promising due to the fast development of nanotechnology. However, there are still some challenges and limitations that need to be considered. Based on the above contents, the present article analyzes the progress in developing functional nanoparticles in cancer therapy. Research gaps and promising strategies for the clinical application are discussed.

A Potent Micron Neoantigen Tumor Vaccine GP-Neoantigen Induces Robust Antitumor Activity in Multiple Tumor Models

Therapeutic tumor neoantigen vaccines have been widely studied given their good safety profile and ability to avoid central thymic tolerance. However, targeting antigen-presenting cells (APCs) and inducing robust neoantigen-specific cellular immunity remain challenges. Here, a safe and broad-spectrum neoantigen vaccine delivery system is proposed (GP-Neoantigen) based on β-1,3-glucan particles (GPs) derived from Saccharomyces cerevisiae and coupling peptide antigens with GPs through convenient click chemistry. The prepared system has a highly uniform particle size and high APC targeting specificity. In mice, the vaccine system induced a robust specific CD8⁺ T cell immune response and humoral immune response against various conjugated peptide antigens and showed strong tumor growth inhibitory activity in EG7·OVA lymphoma, B16F10 melanoma, 4T1 breast cancer, and CT26 colon cancer models. The combination of the toll-like receptors (TLRs) agonist PolyI:C and CpG 2395 further enhanced the antitumor response of the particle system, achieving complete tumor clearance in multiple mouse models and inducing long-term rejection of reinoculated tumors. These results provide the broad possibility for its further clinical promotion and personalized vaccine treatment.

Mucosal vaccine delivery: A focus on the breakthrough of specific barriers

Mucosal vaccines can effectively induce an immune response at the mucosal site and form the first line of defense against microbial invasion. The induced mucosal immunity includes the proliferation of effector T cells and the production of IgG and IgA antibodies, thereby effectively blocking microbial infection and transmission. However, after a long period of development, the transformation of mucosal vaccines into clinical use is still relatively slow. To date, fewer than ten mucosal vaccines have been approved. Only seven mucosal vaccines against coronavirus disease 2019 (COVID-19) are under investigation in clinical trials. A representative vaccine is the adenovirus type-5 vectored COVID-19 vaccine (Ad5-nCoV) developed by Chen and coworkers, which is currently in phase III clinical trials. The reason for the limited progress of mucosal vaccines may be the complicated mucosal barriers. Therefore, this review summarizes the characteristics of mucosal barriers and highlights strategies to overcome these barriers for effective mucosal vaccine delivery.

Nanomaterial-Based Drug Delivery System Targeting Lymph Nodes

The lymphatic system plays an indispensable role in humoral balance, lipid metabolism, and immune regulation. The lymph nodes (LNs) are known as the primary sites of tumor metastasis and the metastatic LNs largely affected the prognosis of the patiens. A well-designed lymphatic-targeted system favors disease treatment as well as vaccination efficacy. In recent years, development of nanotechnologies and emerging biomaterials have gained increasing attention in developing lymph-node-targeted drug-delivery systems. By mimicking the endogenous macromolecules or lipid conjugates, lymph-node-targeted nanocarries hold potential for disease diagnosis and tumor therapy. This review gives an introduction to the physiological functions of LNs and the roles of LNs in diseases, followed by a review of typical lymph-node-targeted nanomaterial-based drug-delivery systems (e.g., liposomes, micelles, inorganic nanomaterials, hydrogel, and nanocapsules). Future perspectives and conclusions concerned with lymph-node-targeted drug-delivery systems are also provided.

Nanotechnology for the management of COVID-19 during the pandemic and in the post-pandemic era

Following the global COVID-19 pandemic, nanotechnology has been at the forefront of research efforts and enables the fast development of diagnostic tools, vaccines and antiviral treatment for this novel virus (SARS-CoV-2). In this review, we first summarize nanotechnology with regard to the detection of SARS-CoV-2, including nanoparticle-based techniques such as rapid antigen testing, and nanopore-based sequencing and sensing techniques. Then we investigate nanotechnology as it applies to the development of COVID-19 vaccines and anti-SARS-CoV-2 nanomaterials. We also highlight nanotechnology for the post-pandemic era, by providing tools for the battle with SARS-CoV-2 variants and for enhancing the global distribution of vaccines. Nanotechnology not only contributes to the management of the ongoing COVID-19 pandemic but also provides platforms for the prevention, rapid diagnosis, vaccines and antiviral drugs of possible future virus outbreaks.

Sustained delivery approaches to improving adaptive immune responses

The immune system is one of the most important, complex biological networks regulating and protecting human health. Its precise modulation can prevent deadly infections and fight cancer. Accordingly, prophylactic vaccines and cancer immunotherapies are some of the most powerful technologies to protect against potential dangers through training of the immune system. Upon immunization, activation and maturation of B and T cells of the adaptive immune system are necessary for development of proper humoral and cellular protection. Yet, the exquisite organization of the immune system requires spatiotemporal control over the exposure of immunomodulatory signals. For example, while the human immune system has evolved to develop immunity to natural pathogenic infections that often last for weeks, current prophylactic vaccination technologies only expose the immune system to immunomodulatory signals for hours to days. It has become clear that leveraging sustained release technologies to prolong immunogen and adjuvant exposure can increase the potency, durability, and quality of adaptive immune responses. Over the past several years, tremendous breakthroughs have been made in the design of novel biomaterials such as nanoparticles, microparticles, hydrogels, and microneedles that can precisely control and the presentation of immunomodulatory signals to the immune system. In this review, we discuss relevant sustained release strategies and their corresponding benefits to cellular and humoral responses.

Self-adjuvanting nanovaccines boost lung-resident CD4+ T cell immune responses in BCG-primed mice

Heterologous vaccine regimens could extend waning protection in the global population immunized with Mycobacterium bovis Bacille Calmette-Guerin (BCG). We demonstrate that pulmonary delivery of peptide nanofibers (PNFs) bearing an Ag85B CD4+ T cell epitope increased the frequency of antigen-specific T cells in BCG-primed mice, including heterogenous populations with tissue resident memory (Trm) and effector memory (Tem) phenotype, and functional cytokine recall. Adoptive transfer of dendritic cells pulsed with Ag85B-bearing PNFs further expanded the frequency and functional repertoire of memory CD4+ T cells. Transcriptomic analysis suggested that the adjuvanticity of peptide nanofibers is, in part, due to the release of damage-associated molecular patterns. A single boost with monovalent Ag85B PNF in BCG-primed mice did not reduce lung bacterial burden compared to BCG alone following aerosol Mtb challenge. These findings support the need for novel BCG booster strategies that activate pools of Trm cells with potentially diverse localization, trafficking, and immune function.

Therapeutic Vaccines Targeting Neoantigens to Induce T-Cell Immunity against Cancers

Cancer immunotherapy has achieved multiple clinical benefits and has become an indispensable component of cancer treatment. Targeting tumor-specific antigens, also known as neoantigens, plays a crucial role in cancer immunotherapy. T cells of adaptive immunity that recognize neoantigens, but do not induce unwanted off-target effects, have demonstrated high efficacy and low side effects in cancer immunotherapy. Tumor neoantigens derived from accumulated genetic instability can be characterized using emerging technologies, such as high-throughput sequencing, bioinformatics, predictive algorithms, mass-spectrometry analyses, and immunogenicity validation. Neoepitopes with a higher affinity for major histocompatibility complexes can be identified and further applied to the field of cancer vaccines. Therapeutic vaccines composed of tumor lysates or cells and DNA, mRNA, or peptides of neoantigens have revoked adaptive immunity to kill cancer cells in clinical trials. Broad clinical applicability of these therapeutic cancer vaccines has emerged. In this review, we discuss recent progress in neoantigen identification and applications for cancer vaccines and the results of ongoing trials.

Inhalable polymer nanoparticles for versatile mRNA delivery and mucosal vaccination

An inhalable platform for mRNA therapeutics would enable minimally invasive and lung targeted delivery for a host of pulmonary diseases. Development of lung targeted mRNA therapeutics has been limited by poor transfection efficiency and risk of vehicle-induced pathology. Here we report an inhalable polymer-based vehicle for delivery of therapeutic mRNAs to the lung. We optimized biodegradable poly(amine-co-ester) polyplexes for mRNA delivery using end group modifications and polyethylene glycol. Our polyplexes achieved high transfection of mRNA throughout the lung, particularly in epithelial and antigen-presenting cells. We applied this technology to develop a mucosal vaccine for SARS-CoV-2. Intranasal vaccination with spike protein mRNA polyplexes induced potent cellular and humoral adaptive immunity and protected K18-hACE2 mice from lethal viral challenge.

One-sentence summary

Inhaled polymer nanoparticles (NPs) achieve high mRNA expression in the lung and induce protective immunity against SARS-CoV-2.

Nanocarriers-Assisted Needle-Free Vaccine Delivery Through Oral and Intranasal Transmucosal Routes: A Novel Therapeutic Conduit

Drug delivery using oral route is the most popular, convenient, safest and least expensive approach. It includes oral transmucosal delivery of bioactive compounds as the mucosal cavity offers an intriguing approach for systemic drug distribution. Owing to the dense vascular architecture and high blood flow, oral mucosal layers are easily permeable and can be an ideal site for drug administration. Recently, the transmucosal route is being investigated for other therapeutic candidates such as vaccines for their efficient delivery. Vaccines have the potential to trigger immune reactions and can act as both prophylactic and therapeutic conduit to a variety of diseases. Administration of vaccines using transmucosal route offers multiple advantages, the most important one being the needle-free (non-invasive) delivery. Development of needle-free devices are the most recent and pioneering breakthrough in the delivery of drugs and vaccines, enabling patients to avoid needles, reducing anxiety, pain and fear as well as improving compliance. Oral, nasal and aerosol vaccination is a novel immunization approach that utilizes a nanocarrier to administer the vaccine. Nanocarriers improve the bioavailability and serve as adjuvants to elicit a stronger immune response, resulting in increased effectiveness of vaccination. Drugs and vaccines with lower penetration abilities can also be delivered transmucosally while maintaining their biological function. The development of micro/nanocarriers for transmucosal delivery of macromolecules, vaccines and other substances is currently drawing much attention and a number of studies were performed recently. This comprehensive review is aimed to summarize the most recent investigations on needle-free and non-invasive approaches for the delivery of vaccines using oral transmucosal route, their strengths and associated challenges. The oral transmucosal vaccine delivery by nanocarriers is the most upcoming advancement in efficient vaccine delivery and this review would help further research and trials in this field.

Pulmonary delivery of mucosal nanovaccines

Mucosal vaccination can elicit both systemic and mucosal immunity, and therefore has the potential to not only treat mucosal immune diseases, prevent the pathogen infection at the mucosal entry sites, but also treat distant or systemic immune disorders. However, only a few mucosal vaccines have been approved for human use in the clinic. Effective mucosal immunization requires the delivery of immunogenic agents to appropriate mucosal surfaces, which remains significantly challenging due to the essential biological barriers presenting at mucosal tissues. In the past decade, remarkable progress has been made in the development of pulmonary mucosal nanovaccines. The nanovaccines leverage advanced nanoparticle-based pulmonary delivery technologies on the characteristics of large surface area and rich antigen presentation cell environment of the lungs for triggering robust immune protection against various mucosal diseases. Herein, we review current methods and formulations of pulmonary delivery, discuss the design strategies of mucosal nanovaccines for potent and long-lasting immune responses, and highlight recent advances in the application of lipid-based pulmonary nanovaccines against mucosal diseases. These advances promise to accelerate the development of novel mucosal nanovaccines for the prophylaxis and therapy of infectious diseases, and cancer, as well as autoimmune disorders at mucosal tissues.

Vaccine Considerations for Multiple Sclerosis in the COVID-19 Era

People with multiple sclerosis (MS) are at risk for infections that can result in amplification of baseline symptoms and possibly trigger clinical relapses. Vaccination can prevent infection through the activation of humoral and cellular immune responses. This is particularly pertinent in the era of emerging novel vaccines against severe acute respiratory syndrome coronavirus 2, the virus that causes coronavirus disease 2019 (COVID-19). MS disease-modifying therapies (DMTs), which affect the immune system, may impact immune responses to COVID-19 vaccines in people with MS. The objective of this article is to provide information on immune system responses to vaccinations and review previous studies of vaccine responses in people with MS to support the safety and importance of receiving currently available and emerging COVID-19 vaccines. Immunological studies have shown that coordinated interactions between T and B lymphocytes of the adaptive immune system are key to successful generation of immunological memory and production of neutralizing antibodies following recognition of vaccine antigens by innate immune cells. CD4+ T cells are essential to facilitate CD8+ T cell and B cell activation, while B cells drive and sustain T cell memory. Data suggest that some classes of DMT, including type 1 interferons and glatiramer acetate, may not significantly impair the response to vaccination. DMTs-such as sphingosine-1-phosphate receptor modulators, which sequester lymphocytes from circulation; alemtuzumab; and anti-CD20 therapies, which rely on depleting populations of immune cells-have been shown to attenuate responses to conventional vaccines. Currently, three COVID-19 vaccines have been granted emergency use authorization in the USA on the basis of promising interim findings of ongoing trials. Because analyses of these vaccines in people with MS are not available, decisions regarding COVID-19 vaccination and DMT choice should be informed by data and expert consensus, and personalized with considerations for disease burden, risk of infection, and other factors.

Biomaterial-based immunoengineering to fight COVID-19 and infectious diseases

Infection by SARS-CoV-2 virus often induces the dysregulation of immune responses, tissue damage, and blood clotting. Engineered biomaterials from the nano- to the macroscale can provide targeted drug delivery, controlled drug release, local immunomodulation, enhanced immunity, and other desirable functions to coordinate appropriate immune responses and to repair tissues. Based on the understanding of COVID-19 disease progression and immune responses to SARS-CoV-2, we discuss possible immunotherapeutic strategies and highlight biomaterial approaches from the perspectives of preventive immunization, therapeutic immunomodulation, and tissue healing and regeneration. Successful development of biomaterial platforms for immunization and immunomodulation will not only benefit COVID-19 patients, but also have broad applications for a variety of infectious diseases.

Engineering Vaccines for Tissue-Resident Memory T Cells

In recent years, tissue-resident memory T cells (TRM) have attracted significant attention in the field of vaccine development. Distinct from central and effector memory T cells, TRM cells take up residence in home tissues such as the lung or urogenital tract and are ideally positioned to respond quickly to pathogen encounter. TRM have been found to play a role in the immune response against many globally important infectious diseases for which new or improved vaccines are needed, including influenza and tuberculosis. It is also increasingly clear that TRM play a pivotal role in cancer immunity. Thus, vaccines that can generate this memory T cell population are highly desirable. The field of immunoengineering-that is, the application of engineering principles to study the immune system and design new and improved therapies that harness or modulate immune responses-is ideally poised to provide solutions to this need for next-generation TRM vaccines. This review covers recent developments in vaccine technologies for generating TRM and protecting against infection and cancer, including viral vectors, virus-like particles, and synthetic and natural biomaterials. In addition, it offers critical insights on the future of engineering vaccines for tissue-resident memory T cells.

Robust induction of TRMs by combinatorial nanoshells confers cross-strain sterilizing immunity against lethal influenza viruses

Antigen-specific lung-resident memory T cells (T_RMs) constitute the first line of defense that mediates rapid protection against respiratory pathogens and inspires novel vaccine designs against infectious pandemic threats, yet effective means of inducing T_RMs, particularly via non-viral vectors, remain challenging. Here, we demonstrate safe and potent induction of lung-resident T_RMs using a biodegradable polymeric nanoshell that co-encapsulates antigenic peptides and TLR9 agonist CpG-oligodeoxynucleotide (CpG-ODN) in a virus-mimicking structure. Through subcutaneous priming and intranasal boosting, the combinatorial nanoshell vaccine elicits prominent lung-resident CD4⁺ and CD8⁺ T cells that surprisingly show better durability than live viral infections. In particular, nanoshells containing CpG-ODN and a pair of conserved class I and II major histocompatibility complex-restricted influenza nucleoprotein-derived antigenic peptides are demonstrated to induce near-sterilizing immunity against lethal infections with influenza A viruses of different strains and subtypes in mice, resulting in rapid elimination of replicating viruses. We further examine the pulmonary transport dynamic and optimal composition of the nanoshell vaccine conducive for robust T_RM induction as well as the benefit of subcutaneous priming on T_RM replenishment. The study presents a practical vaccination strategy for inducing protective T_RM-mediated immunity, offering a compelling platform and critical insights in the ongoing quest toward a broadly protective vaccine against universal influenza as well as other respiratory pathogens.

Exploiting albumin as a mucosal vaccine chaperone for robust generation of lung-resident memory T cells

Tissue-resident memory T cells (TRMs) can profoundly enhance mucosal immunity, but parameters governing TRM induction by vaccination remain poorly understood. Here, we describe an approach exploiting natural albumin transport across the airway epithelium to enhance mucosal TRM generation by vaccination. Pulmonary immunization with albumin-binding amphiphile conjugates of peptide antigens and CpG adjuvant (amph-vaccines) increased vaccine accumulation in the lung and mediastinal lymph nodes (MLNs). Amph-vaccines prolonged antigen presentation in MLNs over 2 weeks, leading to 25-fold increased lung-resident T cell responses over traditional immunization and enhanced protection from viral or tumor challenge. Mimicking such prolonged exposure through repeated administration of soluble vaccine revealed that persistence of both antigen and adjuvant was critical for optimal TRM induction, mediated through T cell priming in MLNs after prime, and directly in the lung tissue after boost. Thus, vaccine persistence strongly promotes TRM induction, and amph-conjugates may provide a practical approach to achieve such kinetics in mucosal vaccines.

Nanotechnology against the novel coronavirus (severe acute respiratory syndrome coronavirus 2): diagnosis, treatment, therapy and future perspectives

COVID-19, as an emerging infectious disease, has caused significant mortality and morbidity along with socioeconomic impact. No effective treatment or vaccine has been approved yet for this pandemic disease. Cutting-edge tools, especially nanotechnology, should be strongly considered to tackle this virus. This review aims to propose several strategies to design and fabricate effective diagnostic and therapeutic agents against COVID-19 by the aid of nanotechnology. Polymeric, inorganic self-assembling materials and peptide-based nanoparticles are promising tools for battling COVID-19 as well as its rapid diagnosis. This review summarizes all of the exciting advances nanomaterials are making toward COVID-19 prevention, diagnosis and therapy.

Systemic and Mucosal B and T Cell Responses Upon Mucosal Vaccination of Teleost Fish

The development of mucosal vaccines against pathogens is currently a highly explored area of research in both humans and animals. This is due to the fact that mucosal vaccines have the potential to best elicit protective responses at these mucosal surfaces, which represent the frontline of host defense, thus blocking the pathogen at its initial replication sites. However, in order to provide an efficient long-lasting protection, these mucosal vaccines have to be capable of eliciting an adequate systemic immune response in addition to local responses. In aquaculture, the need for mucosal vaccines has further practical implications, as these vaccines would avoid the individual manipulation of fish out of the water, being beneficial from both an economic and animal welfare point of view. However, how B and T cells are organized in teleost fish within these mucosal sites and how they respond to mucosally delivered antigens varies greatly when compared to mammals. For this reason, it is important to establish which mucosally delivered antigens have the capacity to induce strong and long-lasting B and T cell responses. Hence, in this review, we have summarized what is currently known regarding the adaptive immune mechanisms that are induced both locally and systemically in fish after mucosal immunization through different routes of administration including oral and nasal vaccination, anal intubation and immersion vaccination. Finally, based on the data presented, we discuss how mucosal vaccination strategies could be improved to reach significant protection levels in these species.

Application of Bionanomaterials in Tumor Immune Microenvironment Therapy

Targeted therapy for the cancer immune system has become a clinical reality with remarkable success. Immune checkpoint blockade therapy and chimeric antigen receptor T-cell (CAR-T) immunotherapy are clinically effective in a variety of cancers. However, the clinical utility of immunotherapy in cancer is limited by severe off-target toxicity, long processing time, limited efficacy, and extremely high cost. Bionanomaterials combined with these therapies address these issues by enhancing immune regulation, integrating the synergistic effects of different molecules, and, most importantly, targeting and manipulating immune cells within the tumor. In this review, we will summarize the most current researches on bionanomaterials for targeted regulation of tumor-associated macrophages, myeloid-derived suppressor cells, dendritic cells, T lymphocyte cells, and cancer-associated fibroblasts and summarize the prospects and challenges of cell-targeted therapy and clinical translational potential in a tumor immune microenvironment in cancer treatment.

Strategy to enhance dendritic cell-mediated DNA vaccination in the lung

We here introduce a new paradigm to promote pulmonary DNA vaccination. Specifically, we demonstrate that nanoparticles designed to rapidly penetrate airway mucus (mucus-penetrating particle or MPP) enhance the delivery of inhaled model DNA vaccine (i.e. ovalbumin-expressing plasmids) to pulmonary dendritic cells (DC), leading to robust and durable local and trans-mucosal immunity. In contrast, mucus-impermeable particles were poorly taken up by pulmonary DC following inhalation, despite their superior ability to mediate DC uptake in vitro compared to MPP. In addition to the enhanced immunity achieved in mucosal surfaces, inhaled MPP unexpectedly provided significantly greater systemic immune responses compared to gold-standard approaches applied in the clinic for systemic vaccination, including intradermal injection and intramuscular electroporation. We also showed here that inhaled MPP significantly enhanced the survival of an orthotopic mouse model of aggressive lung cancer compared to the gold-standard approaches. Importantly, we discovered that MPP-mediated pulmonary DNA vaccination induced memory T-cell immunity, particularly the ready-to-act effector memory-biased phenotype, both locally and systemically. The findings here underscore the importance of breaching the airway mucus barrier to facilitate DNA vaccine uptake by pulmonary DC and thus to initiate full-blown immune responses.

Oral immunization induces a novel CXCR6+ β7+ intraepithelial lymphocyte subset predominating in the small intestine

Intestinal T cells form a central part of the front-line defence against foreign organisms and need to be situated in the mucosa where infection occurs. It is well accepted that immunization by a mucosal route favours localization of antigen-specific effector T cells in the mucosal epithelium, while systemic immunization does not. The aim of the study is to determine how homing receptors are specifically involved in retaining effector T cells in the small intestine after oral immunization. We here demonstrate that the chemokine receptor CXCR6, integrins β7 and CD29 contribute differentially to the epithelial retention phenotype of CD8⁺ T cells in the small intestine of mice. CD8⁺ intraepithelial lymphocytes (IELs) of unvaccinated mice are predominantly β7 single positives, and subcutaneous immunization-induced antigen-specific CD8⁺ effector IELs are mainly composed of CXCR6⁺ , CD29⁺ and CXCR6⁺ CD29⁺ cells. Strikingly, the majority of oral immunization-induced antigen-specific CD8⁺ effector IELs exhibit a distinct, tissue-specific CXCR6⁺ β7⁺ double-positive phenotype, cytotoxic potential and enhanced intraepithelial localization. Transfer of antigen-specific CD8⁺ T cells preactivated with certain immuno-stimuli (such as monophosphoryl lipid A) results in increased accumulation of donor IELs with the CXCR6⁺ β7⁺ phenotype. As β7 exclusively paired with αE on IELs, our results strongly suggest that CXCR6 may cooperate with the heterodimer αEβ7 to preferentially retain intestinally induced effector IELs in the epithelium. The identification of this novel IEL phenotype has significant implications for the development of vaccines and therapeutic strategies to enhance gut immunity.

Proton-driven transformable nanovaccine for cancer immunotherapy

Cancer vaccines hold great promise for improved cancer treatment. However, endosomal trapping and low immunogenicity of tumour antigens usually limit the efficiency of vaccination strategies. Here, we present a proton-driven nanotransformer-based vaccine, comprising a polymer-peptide conjugate-based nanotransformer and loaded antigenic peptide. The nanotransformer-based vaccine induces a strong immune response without substantial systemic toxicity. In the acidic endosomal environment, the nanotransformer-based vaccine undergoes a dramatic morphological change from nanospheres (about 100 nanometres in diameter) into nanosheets (several micrometres in length or width), which mechanically disrupts the endosomal membrane and directly delivers the antigenic peptide into the cytoplasm. The re-assembled nanosheets also boost tumour immunity via activation of specific inflammation pathways. The nanotransformer-based vaccine effectively inhibits tumour growth in the B16F10-OVA and human papilloma virus-E6/E7 tumour models in mice. Moreover, combining the nanotransformer-based vaccine with anti-PD-L1 antibodies results in over 83 days of survival and in about half of the mice produces complete tumour regression in the B16F10 model. This proton-driven transformable nanovaccine offers a robust and safe strategy for cancer immunotherapy.

Nano-based approaches in the development of antiviral agents and vaccines

Outbreaks and the rapid transmission of viruses, such as coronaviruses and influenza viruses, are serious threats to human health. A major challenge in combating infectious diseases caused by viruses is the lack of effective methods for prevention and treatment. Nanotechnology has provided a basis for the development of novel antiviral strategies. Owing to their large modifiable surfaces that can be functionalized with multiple molecules to realize sophisticated designs, nanomaterials have been developed as nanodrugs, nanocarriers, and nano-based vaccines to effectively induce sufficient immunologic memory. From this perspective, we introduce various nanomaterials with diverse antiviral mechanisms and summarize how nano-based antiviral agents protect against viral infection at the molecular, cellular, and organismal levels. We summarize the applications of nanomaterials for defense against emerging viruses by trapping and inactivating viruses and inhibiting viral entry and replication. We also discuss recent progress in nano-based vaccines with a focus on the mechanisms by which nanomaterials contribute to immunogenicity. We further describe how nanotechnology may improve vaccine efficacy by delivering large amounts of antigens to target immune cells and enhancing the immune response by mimicking viral structures and activating dendritic cells. Finally, we provide an overview of future prospects for nano-based antiviral agents and vaccines.

Nanoemulsion adjuvantation strategy of tumor-associated antigen therapy rephrases mucosal and immunotherapeutic signatures following intranasal vaccination

BACKGROUND

Emulsion adjuvants are a potent tool for effective vaccination; however, the size matters on mucosal signatures and the mechanism of action following intranasal vaccination remains unclear. Here, we launch a mechanistic study to address how mucosal membrane interacts with nanoemulsion of a well-defined size at cellular level and to elucidate the impact of size on tumor-associated antigen therapy.

METHODS

The squalene-based emulsified particles at the submicron/nanoscale could be elaborated by homogenization/extrusion. The mucosal signatures following intranasal delivery in mice were evaluated by combining whole-mouse genome microarray and immunohistochemical analysis. The immunological signatures were tested by assessing their ability to influence the transportation of a model antigen ovalbumin (OVA) across nasal mucosal membranes and drive cellular immunity in vivo. Finally, the cancer immunotherapeutic efficacy is monitored by assessing tumor-associated antigen models consisting of OVA protein and tumor cells expressing OVA epitope.

RESULTS

Uniform structures with ~200 nm in size induce the emergence of membranous epithelial cells and natural killer cells in nasal mucosal tissues, facilitate the delivery of protein antigen across the nasal mucosal membrane and drive broad-spectrum antigen-specific T-cell immunity in nasal mucosal tissues as well as in the spleen. Further, intranasal vaccination of the nanoemulsion could assist the antigen to generate potent antigen-specific CD8+ cytotoxic T-lymphocyte response. When combined with immunotherapeutic models, such an effective antigen-specific cytotoxic activity allowed the tumor-bearing mice to reach up to 50% survival 40 days after tumor inoculation; moreover, the optimal formulation significantly attenuated lung metastasis.

CONCLUSIONS

In the absence of any immunostimulator, only 0.1% content of squalene-based nanoemulsion could rephrase the mucosal signatures following intranasal vaccination and induce broad-spectrum antigen-specific cellular immunity, thereby improving the efficacy of tumor-associated antigen therapy against in situ and metastatic tumors. These results provide critical mechanistic insights into the adjuvant activity of nanoemulsion and give directions for the design and optimization of mucosal delivery for vaccine and immunotherapy.

Lymph-directed immunotherapy - Harnessing endogenous lymphatic distribution pathways for enhanced therapeutic outcomes in cancer

The advent of immunotherapy has revolutionised the treatment of some cancers. Harnessing the immune system to improve tumour cell killing is now standard clinical practice and immunotherapy is the first line of defence for many cancers that historically, were difficult to treat. A unifying concept in cancer immunotherapy is the activation of the immune system to mount an attack on malignant cells, allowing the body to recognise, and in some cases, eliminate cancer. However, in spite of a significant proportion of patients that respond well to treatment, there remains a subset who are non-responders and a number of cancers that cannot be treated with these therapies. These limitations highlight the need for targeted delivery of immunomodulators to both tumours and the effector cells of the immune system, the latter being highly concentrated in the lymphatic system. In this context, macromolecular therapies may provide a significant advantage. Macromolecules are too large to easily access blood capillaries and instead typically exhibit preferential uptake via the lymphatic system. In contexts where immune cells are the therapeutic target, particularly in cancer therapy, this may be advantageous. In this review, we examine in brief the current immunotherapy approaches in cancer and how macromolecular and nanomedicine strategies may improve the therapeutic profiles of these drugs. We subsequently discuss how therapeutics directed either by parenteral or mucosal administration, can be taken up by the lymphatics thereby accessing a larger proportion of the body's immune cells. Finally, we detail drug delivery strategies that have been successfully employed to target the lymphatics.

Modulating lung immune cells by pulmonary delivery of antigen-specific nanoparticles to treat autoimmune disease

Antigen-specific particles can treat autoimmunity, and pulmonary delivery may provide for easier delivery than intravenous or subcutaneous routes. The lung is a "hub" for autoimmunity where autoreactive T cells pass before arriving at disease sites. Here, we report that targeting lung antigen-presenting cells (APCs) via antigen-loaded poly(lactide-co-glycolide) particles modulates lung CD4+ T cells to tolerize murine experimental autoimmune encephalomyelitis (EAE), a mouse model of multiple sclerosis. Particles directly delivered to the lung via intratracheal administration demonstrated more substantial reduction in EAE severity when compared with particles delivered to the liver and spleen via intravenous administration. Intratracheally delivered particles were associated with lung APCs and decreased costimulatory molecule expression on the APCs, which inhibited CD4+ T cell proliferation and reduced their population in the central nervous system while increasing them in the lung. This study supports noninvasive pulmonary particle delivery, such as inhalable administration, to treat autoimmune disease.