Masked Delivery of Allergen in Nanoparticles Safely Attenuates Anaphylactic Response in Murine Models of Peanut Allergy

Allergen-Encapsulating Nanoparticles Reprogram Pathogenic Allergen-Specific Th2 Cells to Suppress Food Allergy

Food allergy is a prevalent, potentially deadly disease caused by inadvertent sensitization to benign food antigens. Pathogenic Th2 cells are a major driver for disease, and allergen-specific immunotherapies (AIT) aim to increase the allergen threshold required to elicit severe allergic symptoms. However, the majority of AIT approaches require lengthy treatments and convey transient disease suppression, likely due to insufficient targeting of pathogenic Th2 responses. Here, the ability of allergen-encapsulating nanoparticles to directly suppress pathogenic Th2 responses and reactivity is investigated in a mouse model of food allergy. NPs associate with pro-tolerogenic antigen presenting cells, provoking accumulation of antigen-specific, functionally suppressive regulatory T cells in the small intestine lamina propria. Two intravenous doses of allergen encapsulated in poly(lactide-co-glycolide) nanoparticles (NPs) significantly reduces oral food challenge (OFC)-induced anaphylaxis. Importantly, NP treatment alters the fates of pathogenic allergen-specific Th2 cells, reprogramming these cells toward CD25+FoxP3+ regulatory and CD73+FR4+ anergic phenotypes. NP-mediated reductions in the frequency of effector cells in the gut and mast cell degranulation following OFC are also demonstrated. These studies reveal mechanisms by which an allergen-encapsulating NP therapy and, more broadly, allergen-specific immunotherapies, can rapidly attenuate allergic responses by targeting pathogenic Th2 cells.

Engineering platforms for localized long-acting immune modulation

Systemic immunotherapeutics have been a clinical staple in the treatment of cancer, infectious diseases, organ and cell transplantation, autoimmunity, and allergies. Although their utility remains unquestioned, systemic administration of these drugs is associated with limited efficacy, significant adverse off-target effects, transient activity, and the requirement for frequent repeated dosing. To this end, recent technological advancements have provided novel means for sustained drug delivery to specific tissues and targeted localized approaches for immunotherapeutics. In this article, we present various cutting-edge platform technologies, including implants, multireservoir systems, and scaffolds encapsulating immunomodulatory agents for local administration. Examples of their application in cancer, cell transplantation, allergy, and infectious diseases are discussed, highlighting the potential of such systems for innovative immunomodulatory intervention.

Engineering nanoparticle therapeutics for food allergy

Food allergy is a growing public health issue among children and adults that can lead to life-threatening anaphylaxis following allergen exposure. The criterion standard for disease management includes food avoidance and emergency epinephrine administration because current allergen-specific immunotherapy treatments are limited by adverse events and unsustained desensitization. A promising approach to remedy these shortcomings is the use of nanoparticle-based therapies that disrupt disease-driving immune mechanisms and induce more sustained tolerogenic immune pathways. The pathophysiology of food allergy includes multifaceted interactions between effector immune cells, including lymphocytes, antigen-presenting cells, mast cells, and basophils, mainly characterized by a TH2 cell response. Regulatory T cells, TH1 cell responses, and suppression of other major allergic effector cells have been found to be major drivers of beneficial outcomes in these nanoparticle therapies. Engineered nanoparticle formulations that have shown efficacy at reducing allergic responses and revealed new mechanisms of tolerance include polymeric-, lipid-, and emulsion-based nanotherapeutics. This review highlights the recent engineering design of these nanoparticles, the mechanisms induced by them, and their future potential therapeutic targets.

Therapeutic synthetic and natural materials for immunoengineering

Immunoengineering is a rapidly evolving field that has been driving innovations in manipulating immune system for new treatment tools and methods. The need for materials for immunoengineering applications has gained significant attention in recent years due to the growing demand for effective therapies that can target and regulate the immune system. Biologics and biomaterials are emerging as promising tools for controlling immune responses, and a wide variety of materials, including proteins, polymers, nanoparticles, and hydrogels, are being developed for this purpose. In this review article, we explore the different types of materials used in immunoengineering applications, their properties and design principles, and highlight the latest therapeutic materials advancements. Recent works in adjuvants, vaccines, immune tolerance, immunotherapy, and tissue models for immunoengineering studies are discussed.

Update on In Vitro Diagnostic Tools and Treatments for Food Allergies

Food allergy (FA) is an adverse immunological reaction to a specific food that can trigger a wide range of symptoms from mild to life-threatening. This adverse reaction is caused by different immunological mechanisms, such as IgE-mediated, non-IgE-mediated and mixed IgE-mediated reactions. Its epidemiology has had a significant increase in the last decade, more so in developed countries. It is estimated that approximately 2 to 10% of the world's population has FA and this number appears to be increasing and also affecting more children. The diagnosis can be complex and requires the combination of different tests to establish an accurate diagnosis. However, the treatment of FA is based on avoiding the intake of the specific allergenic food, thus being very difficult at times and also controlling the symptoms in case of accidental exposure. Currently, there are other immunomodulatory treatments such as specific allergen immunotherapy or more innovative treatments that can induce a tolerance response. It is important to mention that research in this field is ongoing and clinical trials are underway to assess the safety and efficacy of these different immunotherapy approaches, new treatment pathways are being used to target and promote the tolerance response. In this review, we describe the new in vitro diagnostic tools and therapeutic treatments to show the latest advances in FA management. We conclude that although significant advances have been made to improve therapies and diagnostic tools for FA, there is an urgent need to standardize both so that, in their totality, they help to improve the management of FA.

Jak out of the box: Targeting Bruton's tyrosine kinase, sialic acid-binding immunoglobulin-like lectin-8, and Janus kinase 1 in food allergy

There has been rapid growth in the field of immunoglobulin E-mediated food allergy therapeutics, with 1 US Food and Drug Administration-approved therapy in 2020 and several others in various stages of investigation. Oral immunotherapy is the approach with the longest track record of study and provides desensitization for most individuals undertaking the therapy. However, the therapy must be maintained for continued clinical protection, and adverse effects of the therapy are frequent. There is a need to improve allergen immunotherapy safety and durability and to provide a treatment that can target multiple food allergies. In this review, we discuss novel adjunct therapies that may improve safety, such as omalizumab, Bruton's tyrosine kinase inhibitors, and agonists of sialic acid-binding immunoglobulin-like lectin-8, which suppress hypersensitivity responses. We also discuss approaches that may improve magnitude or durability of the treatment response, such as dupilumab and Janus kinase 1 inhibitors.

Suitability of potyviral recombinant virus-like particles bearing a complete food allergen for immunotherapy vaccines

Virus-like particles (VLPs) have been gaining attention as potential platforms for delivery of cargos in nanomedicine. Although animal viruses are largely selected due to their immunostimulatory capacities, VLPs from plant viruses constitute a promising alternative to be considered. VLPs derived from Turnip mosaic virus (TuMV) have proven to present a tridimensional structure suited to display molecules of interest on their surface, making them interesting tools to be studied in theragnostic strategies. Here, we study their potential in the treatment of food allergy by genetically coupling TuMV-derived VLPs to Pru p 3, one of the most dominant allergens in Mediterranean climates. VLPs-Pru p 3 were generated by cloning a synthetic gene encoding the TuMV coat protein and Pru p 3, separated by a linker, into a transient high-expression vector, followed by agroinfiltration in Nicotiana benthamiana plants. The generated fusion protein self-assembled in planta to form the VLPs, which were purified by exclusion chromatography. Their elongated morphology was confirmed by electron microscopy and their size (~400 nm), and monodispersity was confirmed by dynamic light scattering. Initial in vitro characterization confirmed that they were able to induce proliferation of human immune cells. This proliferative capability was enhanced when coupled with the natural lipid ligand of Pru p 3. The resultant formulation, called VLP-Complex, was also able to be transported by intestinal epithelial cells, without affecting the monolayer integrity. In light of all these results, VLP-Complex was furtherly tested in a mouse model of food allergy. Sublingual administration of VLP-Complex could effectively reduce some serological markers associated with allergic responses in mice, such as anti-Pru p 3 sIgE and sIgG2a. Noteworthy, no associated macroscopic, nephritic, or hepatic toxicity was detected, as assessed by weight, blood urea nitrogen (BUN) and galectin-3 analyses, respectively. Our results highlight the standardized production of allergen-coated TuMV-VLPs in N. benthamiana plants. The resulting formula exerts notable immunomodulatory properties without the need for potentially hazardous adjuvants. Accordingly, no detectable toxicity associated to their administration was detected. As a result, we propose them as good candidates to be furtherly studied in the treatment of immune-based pathologies.