Nanoparticle based-immunotherapy against allergy

Treatment of food allergy: Oral immunotherapy, biologics, and beyond

The prevalence of food allergy (FA) has been increasing globally and comes with a heavy burden not just economically, but also on quality of life. Although oral immunotherapy (OIT) is effective at inducing desensitization to food allergens, it has several limitations that weaken its success. Limitations include a long duration of build-up, especially when used for multiple allergens, and a high rate of reported adverse events. Furthermore, OIT may not be effective in all patients. Efforts are underway to identify additional treatment options, either as monotherapy or in combination, to treat FA or enhance the safety and efficacy of OIT. Biologics such as omalizumab and dupilumab, which already have US Food and Drug Administration approval for other atopic conditions have been the most studied, but additional biologics and novel strategies are emerging. In this review, we discuss therapeutic strategies including immunoglobulin E inhibitors, immunoglobulin E disruptors, interleukin-4 and interleukin-13 inhibitors, antialarmins, JAK1 and BTK inhibitors, and nanoparticles, and the data surrounding their application in FA and highlighting their potential.

Interaction between iron oxide nanoparticles (IONs) and primary human immune cells: An up-to-date review of the literature

Nanotechnology has been gaining more and more momentum lately and the potential use of nanomaterials such as nanoparticles (NPs) continues to grow in a variety of activity sectors. Among the NPs, iron oxide nanoparticles (IONs) have retained an increasing interest from the scientific community and industrials due to their superparamagnetic properties allowing their use in many fields, including medicine. However, some undesired effects of IONs and potential risk for human health are becoming increasingly reported in several studies. Although many in vivo studies reported that IONs induce immunotoxicity in different animal models, it is not clear how IONs can alter the biology of primary human immune cells. In this article, we will review the works that have been done regarding the interaction between IONs and primary immune cells. This review also outlines the importance of using primary immune cells in risk assessment of NPs as a reliable strategy for encouraging non-animal studies approaches, to determine risks that might affect the human immune system following different exposure scenarios. Taken all together, the reported observations help to get a more global picture on how IONs alter the human immune system especially the fact that inflammation, known to involve several immune cell types, is frequently reported as an undesired effect of IONs.

Future of Nanotechnology in Food Industry: Challenges in Processing, Packaging, and Food Safety

Over the course of the last several decades, nanotechnology has garnered a growing amount of attention as a potentially valuable technology that has significantly impacted the food industry. Nanotechnology helps in enhancing the properties of materials and structures that are used in various fields such as agriculture, food, pharmacy, and so on. Applications of nanotechnology in the food market have included the encapsulation and distribution of materials to specific locations, the improvement of flavor, the introduction of antibacterial nanoparticles into food, the betterment of prolonged storage, the detection of pollutants, enhanced storage facilities, locating, identifying, as well as consumer awareness. Labeling food goods with nano barcodes helps ensure their security and may also be used to track their distribution. This review article presents a discussion about current advances in nanotechnology along with its applications in the field of food-tech, food packaging, food security, enhancing life of food products, etc. A detailed description is provided about various synthesis routes of nanomaterials, that is, chemical, physical, and biological methods. Nanotechnology is a rapidly improving the field of food packaging and the future holds great opportunities for more enhancement via the development of new nanomaterials and nanosensors.

Nanoparticle applications in food - a review

The use of nanotechnology in the food industry raises uncertainty in many respects. For years, achievements of nanotechnology have been applied mainly in biomedicine and computer science, but recently it has also been used in the food industry. Due to the extremely small (nano) scale, the properties and behavior of nanomaterials may differ from their macroscopic counterparts. They can be used as biosensors to detect reagents or microorganisms, monitor bacterial growth conditions, increase food durability e.g. when placed in food packaging, reducing the amount of certain ingredients without changing the consistency of the product (research on fat substitutes is underway), improve the taste of food, make some nutrients get better absorbed by the body, etc. There are companies on the market that are already introducing nanoparticles into the economy to improve their functionality, e.g. baby feeding bottles. This review focuses on the use of nanoparticles in the food industry, both organic (chitosan, cellulose, proteins) and inorganic (silver, iron, zinc oxide, titanium oxide, etc.). The use of nanomaterials in food production requires compliance with all legal requirements regarding the safety and quantity of nano-processed food products described in this review. In the future, new methods of testing nanoparticles should be developed that would ensure the effectiveness of compounds subjected to, for example, nano-encapsulation, i.e. whether the encapsulation process had a positive impact on the specific properties of these compounds. Nanotechnology has revolutionized our approach towards food engineering (from production to processing), food storage and the creation of new materials and products, and the search for new product applications.

Oral administration of Hsp65-producing Lactococcus lactis attenuates allergic asthma in a murine model

AIMS

Allergic asthma is a chronic inflammatory lung disease characterized by a Th2-type immune response pattern. The development of nonspecific immunotherapy is one of the primary goals for the control of this disease.

METHODS AND RESULTS

In this study, we evaluated the therapeutic effects of Lactococcus lactis-producing mycobacterial heat shock protein 65 (LLHsp65) in an ovalbumin (OVA)-induced allergic asthma model. OVA-challenged BALB/c mice were orally administrated with LLHsp65 for 10 consecutive days. The results demonstrate that LLhsp65 attenuates critical features of allergic inflammation, like airway hyperresponsiveness and mucus production. Likewise, the treatment decreases the pulmonary eosinophilia and the serum level of OVA-specific IgE. In addition to deviating immune responses towards Th1-cytokine profile, increase regulatory T cells, and cytokine levels, such as IL-6 and IL-10.

CONCLUSIONS

Our results reveal that the mucosal immunotherapy of LLHsp65 significantly reduces the overall burden of airway allergic inflammation, suggesting a promising therapeutic strategy for allergic asthma treatment.

SIGNIFICANCE AND IMPACT OF THE STUDY

This research reveals new perspectives on nonspecific immunotherapy based on the delivery of recombinant proteins by lactic acid bacteria to treat of allergic disorders.

Turkish Propolis and Its Nano Form Can Ameliorate the Side Effects of Cisplatin, Which Is a Widely Used Drug in the Treatment of Cancer

This study was performed to determine the effects of chitosan-coated nano-propolis (NP), which is synthesized via a green sonochemical method, and propolis on the side effects of cisplatin (CP), which is a widely used drug in the treatment of cancer. For this aim, 56 rats were divided into seven groups, balancing their body weights (BW). The study was designed as Control, CP (3 mg/kg BW at single dose of CP as intraperitoneal, ip), Propolis (100 mg/kg BW per day of propolis by gavage), NP-10 (10 mg/kg BW of NP per day by gavage), CP + Propolis (3 mg/kg BW of CP and 100 mg/kg BW of propolis), CP + NP-10 (3 mg/kg CP and 10 mg/kg BW of NP), and CP + NP-30 (3 mg/kg BW of CP and 30 mg/kg BW of NP). Propolis and NP (especially NP-30) were preserved via biochemical parameters, oxidative stress, and activation of apoptotic pathways (anti-apoptotic protein: Bcl-2 and pro-apoptotic protein: Bax) in liver and kidney tissues in the toxicity induced by CP. The NP were more effective than propolis at a dose of 30 mg/kg BW and had the potential to ameliorate CP's negative effects while overcoming serious side effects such as liver and kidney damage.

Use of Engineered Nanoparticles (ENPs) for the Study of High-Affinity IgE FcεRI Receptor Engagement and Rat Basophilic Leukemia (RBL) Cell Degranulation

Degranulation of mast cells and basophils occurs after the cross-linking of FcεRI receptor-bound IgE by multivalent allergens, resulting in the release of a range of de novo synthesized and preformed mediators of the allergic response. β-Hexosaminidase release is usually measured as a simple readout for degranulation. Furthermore, the rat basophilic leukemia (RBL)-2H3 cell line is commonly used for measuring degranulation, monitoring β-hexosaminidase release. Here, we describe surface-engineered and modified nanoparticles with specific ligands in order to study the signaling and cellular responses of the RBL-2H3 cell line.

New and old adjuvants in allergen-specific immunotherapy: With a focus on nanoparticles

Allergic diseases have remarkably increased in recent years. Nowadays, efforts for curing and management of these disorders are an important concern worldwide. Allergen-specific immunotherapy (ASIT) has recently gained more attention as a means for the management of allergic diseases. Adjuvants or helper agents are materials applied for better stimulating and shifting of protective responses, and these belong to an extremely diverse collection of complexes. The main function of adjuvants includes acting as depot foundations, transferring vehicles, and immunostimulators. Immunostimulatory adjuvants have gained increasing attention for ASIT. In this regard, the present study provides a review of old and new adjuvants used in allergen immunotherapy.

An Overview of the Applications of Nanomaterials and Nanodevices in the Food Industry

The efficient progress in nanotechnology has transformed many aspects of food science and the food industry with enhanced investment and market share. Recent advances in nanomaterials and nanodevices such as nanosensors, nano-emulsions, nanopesticides or nanocapsules are intended to bring about innovative applications in the food industry. In this review, the current applications of nanotechnology for packaging, processing, and the enhancement of the nutritional value and shelf life of foods are targeted. In addition, the functionality and applicability of food-related nanotechnologies are also highlighted and critically discussed in order to provide an insight into the development and evaluation of the safety of nanotechnology in the food industry.

Myelin oligodendrocyte glycoprotein revisited-sensitive detection of MOG-specific T-cells in multiple sclerosis

Autoreactive CD4+ T-cells are believed to be a main driver of multiple sclerosis (MS). Myelin oligodendrocyte glycoprotein (MOG) is considered an autoantigen, yet doubted in recent years. The reason is in part due to low frequency and titers of MOG autoantibodies and the challenge to detect MOG-specific T-cells. In this study we aimed to analyze T-cell reactivity and frequency utilizing a novel method for detection of antigen-specific T-cells with bead-bound MOG as stimulant. Peripheral blood mononuclear cells (PBMCs) from natalizumab treated persons with MS (n = 52) and healthy controls (HCs) (n = 24) were analyzed by IFNγ/IL-22/IL-17A FluoroSpot. A higher number of IFNγ (P = 0.001), IL-22 (P = 0.003), IL-17A (P < 0.0001) as well as double and triple cytokine producing MOG-specific T-cells were detected in persons with MS compared to HCs. Of the patients, 46.2-59.6% displayed MOG-reactivity. Depletion of CD4+ T-cells or monocytes or blocking HLA-DR completely eliminated the MOG specific response. Anti-MOG antibodies did not correlate with T-cell MOG-responses. In conclusion, we present a sensitive method to detect circulating autoreactive CD4+ T-cells producing IFNγ, IL-22 or IL-17A using MOG as a model antigen. Further, we demonstrate that MOG-specific T-cells are present in approximately half of persons with MS.

Sensitive detection of antigen-specific T-cells using bead-bound antigen for in vitro re-stimulation

Reliable and sensitive detection of antigen specific cells is essential in several fields of research, whether it concerns monitoring responses to infectious agents or exploring the auto-antigen repertoire in autoimmune diseases. Identification of these cells is however difficult, especially when the cells often are rare and methods not sensitive, specific or practical enough. We propose a novel method of processing antigens before stimulation of cells which consists of covalently binding protein antigen to superparamagnetic micro-beads and using denaturing washes to remove contaminants. Peripheral blood mononuclear cells (PBMCs) from healthy donors were stimulated using both cytomegalovirus and tetanus-diphtheria antigen-beads as well as non-antigenic protein-beads as negative control in an IFNγ FluoroSpot assay in order to detect Th1 and CD8⁺ responses. The responses toward the antigen beads were both antigen specific and sensitive, with a detection threshold of 1 IFNγ producing T-cell per 18,000 PBMCs.

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Covalently binding antigen to paramagnetic beads allows for harsh denaturing washes without loss of antigen.

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Microbeads are phagocytosed by antigen presenting cells, resulting in efficient uptake, processing and presentation of the antigens.

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The method allows the usage of relatively impure starting antigen material and whole PBMC samples without high background levels in follow up cellular assays.

Mannosylated Nanoparticles for Oral Immunotherapy in a Murine Model of Peanut Allergy

Peanut allergy is one of the most prevalent and severe of food allergies with no available cure. The aim of this work was to evaluate the potential of an oral immunotherapy based on the use of a roasted peanut extract encapsulated in nanoparticles with immunoadjuvant properties. For this, a polymer conjugate formed by the covalent binding of mannosamine to the copolymer of methyl vinyl ether and maleic anhydride was first synthetized and characterized. Then, the conjugate was used to prepare nanoparticles with an important capability to diffuse through the mucus layer and reach, in a large extent, the intestinal epithelium, including Peyer's patches. Their immunotherapeutic potential was evaluated in a model of presensitized CD1 mice to peanut. After completing therapy, mice underwent an intraperitoneal challenge with peanut extract. Nanoparticle-treatment was associated with both less serious anaphylaxis symptoms and higher survival rates than control, confirming the protective effect of this formulation against the challenge.

Prospects of using nanotechnology for food preservation, safety, and security

The rapid development of nanotechnology has transformed many domains of food science, especially those that involve the processing, packaging, storage, transportation, functionality, and other safety aspects of food. A wide range of nanostructured materials (NSMs), from inorganic metal, metal oxides, and their nanocomposites to nano-organic materials with bioactive agents, has been applied to the food industry. Despite the huge benefits nanotechnology has to offer, there are emerging concerns regarding the use of nanotechnology, as the accumulation of NSMs in human bodies and in the environment can cause several health and safety hazards. Therefore, safety and health concerns as well as regulatory policies must be considered while manufacturing, processing, intelligently and actively packaging, and consuming nano-processed food products. This review aims to provide a basic understanding regarding the applications of nanotechnology in the food packaging and processing industries and to identify the future prospects and potential risks associated with the use of NSMs.

Adjuvants for allergy immunotherapeutics

Allergic diseases are reaching epidemic proportions in developed countries. In particular, food allergy is increasing in prevalence and severity, thus becoming an important socioeconomic burden. Numerous cell types and cell populations, which form an intricate and balanced network, are involved in an immune response. This balance is occasionally disturbed, leading to the onset of different diseases, such as allergic diseases. Antihistamines and corticosteroids provide some degree of relief from the symptoms of allergic conditions. However, the only treatment that can revert the disease is immunotherapy. Nevertheless, specific immunotherapy has at least 2 major drawbacks: it is time-consuming, and it can produce local and even systemic allergic side effects. Immunotherapy's potential goes beyond our current knowledge of the immune response; nevertheless, we can still design strategies to reach a safer immune modulation for treating allergies. This review deals with the use of adjuvants to reduce the undesirable side effects associated with specific allergen immunotherapy. For example, nanoparticles used as immunoadjuvants are offering promising results in preclinical assays.

Protein corona-mediated targeting of nanocarriers to B cells allows redirection of allergic immune responses

BACKGROUND

Nanoparticle (NP)-based vaccines are attractive immunotherapy tools because of their capability to codeliver antigen and adjuvant to antigen-presenting cells. Their cellular distribution and serum protein interaction ("protein corona") after systemic administration and their effect on the functional properties of NPs is poorly understood.

OBJECTIVES

We analyzed the relevance of the protein corona on cell type-selective uptake of dextran-coated NPs and determined the outcome of vaccination with NPs that codeliver antigen and adjuvant in disease models of allergy.

METHODS

The role of protein corona constituents for cellular binding/uptake of dextran-coated ferrous nanoparticles (DEX-NPs) was analyzed both in vitro and in vivo. DEX-NPs conjugated with the model antigen ovalbumin (OVA) and immunostimulatory CpG-rich oligodeoxynucleotides were administered to monitor the induction of cellular and humoral immune responses. Therapeutic effects of this DEX-NP vaccine in mouse models of OVA-induced anaphylaxis and allergic asthma were assessed.

RESULTS

DEX-NPs triggered lectin-induced complement activation, yielding deposition of activated complement factor 3 on the DEX-NP surface. In the spleen DEX-NPs targeted predominantly B cells through complement receptors 1 and 2. The DEX-NP vaccine elicited much stronger OVA-specific IgG_2a production than coadministered soluble OVA plus CpG oligodeoxynucleotides. B-cell binding of the DEX-NP vaccine was critical for IgG_2a production. Treatment of OVA-sensitized mice with the DEX-NP vaccine prevented induction of anaphylactic shock and allergic asthma accompanied by IgE inhibition.

CONCLUSIONS

Opsonization of lectin-coated NPs by activated complement components results in selective B-cell targeting. The intrinsic B-cell targeting property of lectin-coated NPs can be exploited for treatment of allergic immune responses.

Maternal Vaccination. Immunization of Sows during Pregnancy against ETEC Infections

The immunology of pregnancy is an evolving consequence of multiple reciprocal interactions between the maternal and the fetal-placental systems. The immune response must warrant the pregnancy outcome (including tolerance to paternal antigens), but at the same time, efficiently respond to pathogenic challenges. Enterotoxigenic Escherichia coli (ETEC) strains are a major cause of illness and death in neonatal and recently weaned pigs. This review aims to give an overview of the current rationale on the maternal vaccination strategies for the protection of the newborn pig against ETEC. Newborn piglets are immunodeficient and naturally dependent on the maternal immunity transferred by colostrum for protection—a maternal immunity that can be obtained by vaccinating the sow during pregnancy. Our current knowledge of the interactions between the pathogen strategies, virulence factors, and the host immune system is aiding the better design of vaccination strategies in this particular and challenging host status. Challenges include the need for better induction of immunity at the mucosal level with the appropriate use of adjuvants, able to induce the most appropriate and long-lasting protective immune response. These include nanoparticle-based adjuvants for oral immunization. Experiences can be extrapolated to other species, including humans.

Enhanced efficacy of sublingual immunotherapy by liposome-mediated delivery of allergen

Immunotherapy by sublingual administration of allergens provides high patient compliance and has emerged as an alternative to subcutaneous immunotherapy for the treatment of IgE-associated allergic diseases. However, sublingual immunotherapy (SLIT) can cause adverse events. Development of allergen delivery systems enabling more efficient delivery and hence lower allergen load might reduce the adverse events. In the present study, we have investigated neutral and cationic liposomes as delivery systems of ovalbumin (OVA), as a model allergen, in an OVA-induced allergic airway inflammation model. We investigated the liposome carriers' ability to improve tolerance induction of antigens compared to the corresponding dose of free OVA. Mice were treated sublingually over 2 weeks with free or liposome encapsulated OVA followed by intraperitoneal injections and intranasal challenge. Mice sublingually treated with OVA-liposomes showed a significant reduction of airway eosinophilia and splenocyte proliferation in comparison to free OVA. A similar nonsignificant pattern was seen for OVA-specific IgE antibodies. In addition, reduced levels of interferon-γ and interleukin-5 were observed in spleen cell culture supernatants from OVA-liposome-treated mice compared to the sham-treated group. In conclusion, in vivo efficacy data showed that prophylactic SLIT with OVA-liposomes is significantly more effective in preventing allergic inflammation than the corresponding dose of free OVA.

Recent advances in the use of nanoparticles for allergen-specific immunotherapy

The number of patients suffering from allergic asthma and rhinoconjunctivitis has increased dramatically within the last decades. Allergen-specific immunotherapy (AIT) is the only available cause-oriented therapy so far. AIT reduces symptoms, but has also a disease-modifying effect. Disadvantages are a long-lasting procedure, and in a few cases potential systemic adverse reactions. Encapsulation of allergens or DNA vaccines into nanostructures may provide advantages compared to the conventional AIT with noncapsulated allergen extracts: The protein/DNA molecule can be protected from degradation, higher local concentrations and targeted delivery to the site of action appear possible, and most importantly, recognition of encapsulated allergen by the immune system, especially by IgE antibodies, is prevented. AIT with nanoparticles (NPs) may offer a safer and potentially more efficient way of treatment for allergic diseases. In this review, we summarize the use of biodegradable NPs consisting of synthetic or natural polymers, liposomes, and virus-like particles as well as nonbiodegradable NPs like dendrimers, and carbon- or metal-based NPs for AIT. More or less successful applications of these NPs in prophylactic as well as therapeutic vaccination approaches in rodents or other animals as well as first human clinical trials are discussed in detail.

Nanoparticle impact on innate immune cell pattern-recognition receptors and inflammasomes activation

Nanotechnology-based strategies can dramatically impact the treatment, prevention and diagnosis of a wide range of diseases. Despite the unprecedented success achieved with the use of nanomaterials to address unmet biomedical needs and their particular suitability for the effective application of a personalized medicine, the clinical translation of those nanoparticulate systems has still been impaired by the limited understanding on their interaction with complex biological systems. As a result, unexpected effects due to unpredicted interactions at biomaterial and biological interfaces have been underlying the biosafety concerns raised by the use of nanomaterials. This review explores the current knowledge on how nanoparticle (NP) physicochemical and surface properties determine their interactions with innate immune cells, with particular attention on the activation of pattern-recognition receptors and inflammasome. A critical perspective will additionally address the impact of biological systems on the effect of NP on immune cell activity at the molecular level. We will discuss how the understanding of the NP-innate immune cell interactions can significantly add into the clinical translation by guiding the design of nanomedicines with particular effect on targeted cells, thus improving their clinical efficacy while minimizing undesired but predictable toxicological effects.

Nanoparticle-allergen complexes for allergen immunotherapy

Allergen-specific immunotherapy was introduced in clinical settings more than 100 years ago. It remains the only curative approach to treating allergic disorders that ameliorates symptoms, reduces medication costs, and blocks the onset of new sensitizations. Despite this clinical evidence and knowledge of some immunological mechanisms, there remain some open questions regarding the safety and efficacy of this treatment. This suggests the need for novel therapeutic approaches that attempt to reduce the dose and frequency of treatment administration, improving patient compliance, and reducing costs. In this context, the use of novel adjuvants has been proposed and, in recent years, biomedical applications using nanoparticles have been exploited in the attempt to find formulations with improved stability, bioavailability, favorable biodistribution profiles, and the capability of targeting specific cell populations. In this article, we review some of the most relevant regulatory aspects and challenges concerning nanoparticle-based formulations with immunomodulatory potential, their related immunosafety issues, and the nature of the nanoparticles most widely employed in the allergy field. Furthermore, we report in vitro and in vivo data published using allergen/nanoparticle systems, discuss their impact on the immune system in terms of immunomodulatory activity and the reduction of side effects, and show that this strategy is a novel and promising tool for the development of allergy vaccines.

New pharmaceutical approaches for the treatment of food allergies

INTRODUCTION

Allergic diseases constitute one of the most common causes of chronic illness in developed countries. The main mechanism determining allergy is an imbalance between Th1 and Th2 response towards Th2.

AREAS COVERED

This review describes the mechanisms underlying the natural tolerance to food components and the development of an allergic response in sensitized individuals. Furthermore, therapeutic approaches proposed to manage these abnormal immunologic responses food are also presented and discussed.

EXPERT OPINION

In the past, management of food allergies has consisted of the education of patients to avoid the ingestion of the culprit food and to initiate the therapy (e.g. self-injectable epinephrine) in case of accidental ingestion. In recent years, sublingual/oral immunotherapies based on the continuous administration of small amounts of the allergen have been developed. However, the long periods of time needed to obtain significant desensitization and the generation of adverse effects, limit their use. In order to solve these drawbacks, strategies to induce tolerance are being studied, such as the use of either adjuvant immunotherapy in order to facilitate the reversion of the Th2 response towards Th1 or the use of monoclonal antibodies to block the main immunogenic elements.

Amphiphilic poly-N-vynilpyrrolidone nanoparticles: Cytotoxicity and acute toxicity study

The aim of the present study was to evaluate the cytotoxicity against MCF-7 cells and acute intraperitoneal toxicity of amphiphilic poly-N-vinylpyrrolidone nanoparticles to confirm possibility of their application for creation of novel drug delivery systems. The effect of cellular uptake of polymeric nanoparticles on human cancer cell line MCF-7 cells was investigated by MTT assay. MTT analysis showed that tested amphiphilic polymers were essentially non-toxic. In acute toxicity studies, LD50 and other toxicity indexes were evaluated, under which no deaths or treatment related complications were observed even in high concentration treatment for 14 days of experiment. For histological analysis, organs of the animals were weighed and examined. No animal died during the study and no significant changes have been observed regarding body weight, feed consumption, organ weight or histological data. Obtained results show that amphiphilic poly-N-vinylpyrrolidone nanoparticles possessed no toxicity against cells and in animals after intraperitoneal administration. Thus, amphiphilic PVP nanoparticles demonstrate high potential as carriers for novel high-effective drug delivery systems.

Toll-like receptors as targets for allergen immunotherapy

PURPOSE OF REVIEW

Toll-like receptors (TLRs) are novel and promising targets for allergen immunotherapy. Bench studies suggest that TLR agonists reduce Th2 responses and ameliorate airway hyper-responsiveness. In addition, clinical trials are at initial phases to evaluate the safety and efficacy of TLR agonists for the allergen immunotherapy of patients with allergic rhinitis and asthma. (Figure is included in full-text article.)

RECENT FINDINGS

To date, two allergy vaccine-containing TLR agonists have been investigated in clinical trials; Pollinex Quattro and AIC. The former contains monophosphoryl lipid, a TLR4 agonist and the latter contains, CpG motifs activating the TLR9 cascade. Preseasonal subcutaneous injection of both of these allergy vaccines has been safe and efficacious in control of nasal symptoms of patients with allergic rhinitis. CRX-675 (a TLR4 agonist), AZD8848 (a TLR7 agonist), VTX-1463 (a TLR8 agonist) and 1018 ISS and QbG10 (TLR9 agonists) are currently in clinical development for allergic rhinitis and asthma.

SUMMARY

TLR agonists herald promising results for allergen immunotherapy of patients with allergic rhinitis and asthma. Future research should be directed at utilizing these agents for immunotherapy of food allergy (for instance, peanut allergy) as well.

Evidence of seasonality and effects of psychrometry in dry eye disease

PURPOSE

Current models consider the development of dry eye disease (DED) as a more or less continuous process with only minor daily variations. Clinical evidence, however, does suggest the existence of phase-like recurring dry eye complaints that may be linked to seasonal environmental conditions. In this survey-based study, we examined the influence of seasonality in dry eye pathophysiology.

METHODS

A specific protocol for a telephone interview was created. Then, 738 patients suffering from dry eye and/or Sjögren's syndrome were interviewed and asked about the impact of the four seasons and other weather conditions on their ocular symptoms. Data were statistically analysed. All data were compared in respect to the relation between season, gender, country of origin and the presence of comorbidities.

RESULTS

Overall, 47% of respondents stated that seasonal conditions had a high impact on their DED symptoms, with only 15% reporting that there was no seasonal impact on their symptoms. Wind was the most commonly reported weather condition to impact dry eye symptoms (for 71% of patients), followed by sunshine (60%) and heat (42%). Cold weather was also reported to aggravate dry eye sensation by 34% of patients. The two seasons most commonly associated with dry eye complaints were summer and winter (for 51% and 43% of patients, respectively). Only 8% stated that no weather conditions affected their symptoms.

DISCUSSION

This study confirms the seasonal enhancement of dry eye sensations and symptoms. Environmental characteristics such as cold and heat as well as wind were the most commonly cited triggering factors. Geographical differences do exist between the countries surveyed and the seasonal peak of complaints appears related to temperature and humidity. The main seasons of dry eye complaints in Europe were winter and summer. Such seasonal characteristics in ocular surface disease should be kept in mind when considering diagnosis and treatment as well when investigating the ocular surface.

CONCLUSION

Our study confirmed high prevalence of both seasonal and weather-related enhancement of dry eye sensations and symptoms.

Analysis of allergic immune responses in humanized mice

Nowadays, more than 25% of the population in industrial countries are affected by IgE-mediated (atopic) allergic diseases such as allergic rhinitis, asthma and atopic eczema. Due to intensive research on basis of in vitro studies with human immune cells and different murine in vivo models of allergy fundamental mechanisms of allergic immune responses have been elucidated during the last years. However, human studies are restricted and the immune system of mice differs from the human immune system in several aspects so that the transferability of experimental results from mice to men is limited. Humanized mice represent a new tool to analyze the interaction of human immune cells under physiological conditions as far as possible, particularly to test novel therapeutic strategies. This review summarizes the impact of humanized mouse models for the investigation and treatment of allergic diseases.

Biodegradable pH-Sensitive Poly(ethylene glycol) Nanocarriers for Allergen Encapsulation and Controlled Release

In the last decades, the number of allergic patients has increased dramatically. Allergen-specific immunotherapy (SIT) is the only available cause-oriented therapy so far. SIT reduces the allergic symptoms, but also exhibits some disadvantages; that is, it is a long-lasting procedure and severe side effects like anaphylactic shock can occur. In this work, we introduce a method to encapsulate allergens into nanoparticles to avoid severe side effects during SIT. Degradable nanocarriers combine the advantage of providing a physical barrier between the encapsulated cargo and the biological environment as well as responding to certain local stimuli (like pH) to release their cargo. This work introduces a facile strategy for the synthesis of acid-labile poly(ethylene glycol) (PEG)-macromonomers that degrade at pH 5 (physiological pH inside the endolysosome) and can be used for nanocarrier synthesis. The difunctional, water-soluble PEG dimethacrylate (PEG-acetal-DMA) macromonomers with cleavable acetal units were analyzed with 1H NMR, SEC, and MALDI-ToF-MS. Both the allergen and the macromonomers were entrapped inside liposomes as templates, which were produced by dual centrifugation (DAC). Radical polymerization of the methacrylate units inside the liposomes generated allergen-loaded PEG nanocarriers. In vitro studies demonstrated that dendritic cells (DCs) internalize the protein-loaded, nontoxic PEG-nanocarriers. Furthermore, we demonstrate by cellular antigen stimulation tests that the nanocarriers effectively shield the allergen cargo from detection by immunoglobulins on the surface of basophilic leucocytes. Uptake of nanocarriers into DCs does not lead to cell maturation; however, the internalized allergen was capable to induce T cell immune responses.