Virtual reality in preoperative imaging in maxillofacial surgery: implementation of "the next level"?

Not only are current imaging techniques - cone-beam computed tomography (CT), CT, and magnetic resonance imaging (MRI) - becoming more precise in capturing data, but the illustration and interpretation of the acquired images is no longer limited to conventional display screens or projectors. The so-called "virtual reality" (VR) glasses have the potential to engage the viewer in a 3-dimensional space, and ultimately to enable evaluation of the reconstructed anatomical structures from a new perspective. For the first time in the field of oral and maxillofacial surgery (OMFS), a 3-dimensional imaging dataset (cone-beam CT, CT, and MRI) can be evaluated by using VR glasses. A medical student, an OMFS resident, and an OMFS consultant rated the preoperative usability of VR glasses to improve the operative understanding of three cases: a deeply impacted wisdom tooth, a fracture of the lower jaw, and an oncological resection. VR glasses seem to help to simplify operations and give the surgeon a good preoperative overview of the intraoperative findings, particularly in the evaluation of impacted teeth and hard tissue structures. In addition, VR glasses seem to be a promising innovation to help in the training of surgical residents and to teach students. However, the more experienced the surgeon, the smaller is the additional value of VR glasses. Preoperative examination using VR glasses can aid better understanding and planning of the surgical site in the future, and is an innovative piece of advanced technology for displaying CT, cone-beam CT, and MRI anatomical data.

Molecular allergen profiling in horses by microarray reveals Fag e 2 from buckwheat as a frequent sensitizer.

BACKGROUND: Companion animals are also affected by IgE-mediated allergies, but the eliciting molecules are largely unknown. We aimed at refining an allergen microarray to explore sensitization in horses and compare it to the human IgE reactivity profiles. METHODS: Custom-designed allergen microarray was produced on the basis of the ImmunoCAP ISAC technology containing 131 allergens. Sera from 51 horses derived from Europe or Japan were tested for specific IgE reactivity. The included horse patients were diagnosed for eczema due to insect bite hypersensitivity, chronic coughing, recurrent airway obstruction and urticaria or were clinically asymptomatic. RESULTS: Horses showed individual IgE-binding patterns irrespective of their health status, indicating sensitization. In contrast to European and Japanese human sensitization patterns, frequently recognized allergens were Aln g 1 from alder and Cyn d 1 from Bermuda grass, likely due to specific respiratory exposure around paddocks and near the ground. The most prevalent allergen for 72.5% of the tested horses (37/51) was the 2S-albumin Fag e 2 from buckwheat, which recently gained importance not only in human but also in horse diet. CONCLUSION: In line with the One Health concept, covering human health, animal health and environmental health, allergen microarrays provide novel information on the allergen sensitization patterns of the companion animals around us, which may form a basis for allergen-specific preventive and therapeutic concepts.

Comparing immediate-type food allergy in humans and companion animals-revealing unmet needs.

Adverse food reactions occur in human as well as veterinary patients. Systematic comparison may lead to improved recommendations for prevention and treatment in both. In this position paper, we summarize the current knowledge on immediate-type food allergy vs other food adverse reactions in companion animals, and compare this to the human situation. While the prevalence of food allergy in humans has been well studied for some allergens, this remains to be investigated for animal patients, where owner-reported as well as veterinarian-diagnosed food adverse reactions are on the increase. The characteristics of the disease in humans vs dogs, cats, and horses are most often caused by similar, but sometimes species-dependent different pathophysiological mechanisms, prompting the specific clinical symptoms, diagnoses, and treatments. Furthermore, little is known about the allergen molecules causative for type I food allergy in animals, which, like in human patients, could represent predictive biomarkers for risk evaluation. The definite diagnosis of food allergy relies-as in humans-on elimination diet and provocation tests. Besides allergen avoidance in daily practice, novel treatment options and tolerization strategies are underway. Taken together, numerous knowledge gaps were identified in veterinary food allergy, which need to be filled by systematic comparative studies.

Thiomer-coated liposomes harbor permeation enhancing and efflux pump inhibitory properties.

An ideal oral drug carrier should facilitate drug delivery to the gastrointestinal tract and its absorption into the systemic circulation. To meet these requirements, we developed a thiomer-coated liposomal delivery system composed of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and a maleimide-functionalized lipid, to which chitosan-thioglycolic acid (CS-TGA) was covalently coupled. In addition to conventional 77 kDa CS-TGA (CS-TGA77), we tested the 150 kDa homologue (CS-TGA150) as well as an S-protected version of this polymer (CS-TGA150-MNA), in which some of the free SH-groups are conjugated with 6-mercaptonicotinamide to protect them from oxidation. Coupling of CS-TGA to the liposomal surface led to an increase in the particle size of at least 150 nm and an increase in the zeta potential from approximately -33 mV to a maximum of about +36 mV, depending on the polymer. As revealed by fluorescence dequenching the formulations have a storage stability of at least two weeks without releasing any encapsulated compounds. In simulated gastric fluid, the system was shown to be stable over 24 h, while in simulated intestinal fluid, a slow, sustained release of encapsulated compounds was observed. According to our experiments, thiomer-coated liposomes did not induce immunogenic reactions after an oral administration to mice. To evaluate the permeation enhancing and efflux pump inhibiting properties of CS-TGA coated liposomes we monitored the transport of fluoresceinisothiocyanate-dextran (FD(4)) and rhodamine-123 (Rho-123), respectively, through rat small intestine. Permeation studies showed a 2.8-fold higher permeation of FD(4) in the presence of CS-TGA77 coated liposomes and an even 4-fold higher permeation in the presence of CSA-TGA150-MNA coated liposomes. The latter also performed best when we evaluated P-glycoprotein inhibiting properties by monitoring the transport of Rho-123, revealing a 4.2-fold enhancement respective to the buffer control. Taken together, thiomer-coated liposomes were shown to protect encapsulated drugs in the stomach, slowly release them in the small intestine and enhance their absorption through the intestinal tissue by opening tight junctions and inhibiting efflux pumps.

The precise solar shape and its variability.

The precise shape of the Sun has not been convincingly determined, despite half a century of modern photoelectric observations. The expected deviation of the solar-limb shape from a perfect circle is very small, but such asphericity is sensitive to the Sun's otherwise invisible interior conditions, as well as the solar atmosphere. We use evidence from a long-running experiment based in space to show that, when analyzed with sufficiently high spatial resolution, the Sun's oblate shape is distinctly constant and almost completely unaffected by the solar-cycle variability seen on its surface. The solar oblateness is significantly lower than theoretical expectations by an amount that could be explained by a slower differential rotation in the outer few percent of the Sun.

The immediate early gene Ier2 promotes tumor cell motility and metastasis, and predicts poor survival of colorectal cancer patients.

Here, we report unbiased screens for genes expressed in metastatic tumor cells that are associated with cell motility. These screens identified Ier2, an immediate early gene of unknown function, as potentially having a role in tumor cell motility and metastasis. Knockdown of Ier2 in 3T3 fibroblasts inhibited their motility upon relief of contact inhibition in monolayer wounding assays. Furthermore, ectopic Ier2 expression promoted the motility and invasiveness of poorly metastatic 1AS pancreatic tumor cells in vitro. Relief of contact inhibition was associated with translocation of the Ier2 protein from the cytoplasm to the nucleus in both 3T3 fibroblasts and 1AS tumor cells. Importantly, ectopic Ier2 expression in 1AS cells stimulated metastasis formation when cells were implanted into experimental animals. Furthermore, we found elevated Ier2 expression in a wide variety of human tumor types. This correlated with poor metastasis-free and overall survival in patients with colorectal adenocarcinomas. Together, these data reveal Ier2 as a new player in the regulation of tumor progression and metastasis, and suggest that Ier2 may be useful prognostically and therapeutically in the management of cancer.

Anti-acid medication as a risk factor for food allergy.

An important feature for oral allergens is their digestion-resistance during gastrointestinal transit. For some oral allergens, digestion stability is an innate feature, whereas digestion-labile antigens may only persist in times of impairment of the digestive system. In this review, we collect evidence from mouse and human studies that besides the inherent molecular characteristics of a food protein, the stomach function is decisive for the allergenic potential. Gastric acid levels determine the activation of gastric pepsin and also the release of pancreatic enzymes. When anti-ulcer drugs inhibit or neutralize gastric acid, they allow persistence of intact food allergens and protein-bound oral drugs with enhanced capacity to sensitize and elicit allergic reactions via the oral route. Mouse studies further suggest that maternal food allergy arising from co-application of a food protein with anti-acid drugs results in a Th2-biased immune response in the offspring. Especially, anti-ulcer drugs containing aluminum compounds act as Th2 adjuvants. Proton pump inhibitors act on proton secretion but also on expression of the morphogen Sonic hedgehog, which has been related to the development of atrophic gastritis. On the other hand, atrophic gastritis and resulting hypoacidity have previously been correlated with enhanced sensitization risk to food allergens in elderly patients. In summary, impairment of gastric function is a documented risk factor for sensitization against oral proteins and drugs.

Antacids and dietary supplements with an influence on the gastric pH increase the risk for food sensitization.

BACKGROUND: Elevation of the gastric pH increases the risk for sensitization against food allergens by hindering protein breakdown. This can be caused by acid-suppressing medication like sucralphate, H2-receptor blockers and proton pump inhibitors, as shown in recent murine experimental and human observational studies. OBJECTIVE: The aim of the present study was to assess the sensitization capacity of the dietary supplement base powder and of over-the-counter antacids. METHODS: Changes of the pH as well as of protein digestion due to base powder or antacids were measured in vitro. To examine the in vivo influence, BALB/c mice were fed codfish extract with one of the acid-suppressing substances. Read-out of antibody levels in the sera, of cytokine levels of stimulated splenocytes and of intradermal skin tests was performed. RESULTS: The pH of hydrochloric acid was substantially increased in vitro by base powder as well as antacids in a time- and dose-dependent manner. This elevation hindered the digestion of codfish proteins in vitro. A significant increase in codfish-specific IgE antibodies was found in the groups fed codfish combined with Rennie Antacidum or with base powder; the latter also showed significantly elevated IgG1 and IgG2a levels. The induction of an anaphylactic immune response was proven by positive results in intradermal skin tests. CONCLUSIONS: Antacids and dietary supplements influencing the gastric pH increase the risk for sensitization against allergenic food proteins. As these substances are commonly used in the general population without consulting a physician, our data may have a major practical and clinical impact.

Mimotope vaccination for therapy of allergic asthma: anti-inflammatory effects in a mouse model.

BACKGROUND: One of the concerns of allergen-specific immunotherapy is the possible boost of inflammatory allergen-specific T lymphocytes. To address this problem, treatment with B cell epitopes devoid of allergen-specific T cell epitopes would be a promising alternative. OBJECTIVE: In this study, we examined the therapeutic potency of a single mimotope, mimicking a structural IgE epitope of grass pollen allergen Phl p 5 in an established memory mouse model of acute allergic asthma. METHODS: In the experimental set-up, BALB/c mice were primed with intraperitoneal injections of recombinant Phl p 5a (rPhl p 5a) and subsequently aerosol challenged with the nebulized allergen. Mice developed signs of bronchial asthma including hypereosinophilia around bronchi, goblet cell hyperplasia and enhanced mucus production. RESULTS: When the mice were subsequently treated with the grass pollen mimotope coupled to keyhole limpet haemocyanin, bronchial eosinophilic inflammation and mucus hypersecretion decreased. Further, a decrease of Th2 cytokines IL-4 and IL-5 could be observed in the bronchoalveolar lavage (BAL). In contrast to rPhl p 5a, the mimotope was in vitro not able to stimulate splenocytes to proliferation or IL-5 production. Despite not affecting the levels of pre-existing IgE, vaccination with the single mimotope thus rendered anti-inflammatory effects in a mouse model of acute asthma. CONCLUSION: From our data, we conclude that vaccination with a mimotope peptide representing a single IgE epitope of the allergen Phl p 5a and being devoid of allergen-specific T cell epitopes is able to down-regulate inflammation in acute asthma.

Suppression of gastric acid increases the risk of developing immunoglobulin E-mediated drug hypersensitivity: human diclofenac sensitization and a murine sensitization model.

BACKGROUND: Hypersensitivity reactions towards non-steroidal anti-inflammatory drugs (NSAID) are common, although true allergies are detectable only in a subgroup of patients. The current study was prompted by a case observation, where a patient experienced generalized urticaria following his second course of diclofenac and proton pump inhibitor medication, and was found to have diclofenac-specific IgE. During recent years, our group has been investigating the importance of gastric digestion in the development of food allergies, demonstrating anti-acid medication as a risk factor for sensitization against food proteins. OBJECTIVE: Here, we aimed to investigate whether the mechanism of food allergy induction described can also be causative in NSAID allergy, using diclofenac as a paradigm. METHODS: We subjected BALB/c mice to several oral immunization regimens modelled after the patient's medication intake. Diclofenac was applied with or without gastric acid suppression, in various doses, alone or covalently coupled to albumin, a protein abundant in gastric juices. Immune responses were assessed on the antibody level, and functionally examined by in vitro and in vivo crosslinking assays. RESULTS: Only mice receiving albumin-coupled diclofenac under gastric acid suppression developed anti-diclofenac IgG1 and IgE, whereas no immune responses were induced by the drug alone or without gastric acid suppression. Antibody induction was dose dependent with the group receiving the higher dose of the drug showing sustained anti-diclofenac titres. The antibodies induced triggered basophil degranulation in vitro and positive skin tests in vivo. CONCLUSION: Gastric acid suppression was found to be a causative mechanism in the induction of IgE-mediated diclofenac allergy.

Aluminium per se and in the anti-acid drug sucralfate promotes sensitization via the oral route.

BACKGROUND: Aluminium (ALUM) is used as experimental and clinical adjuvant for parenteral vaccine formulation. It is also contained in anti-acid drugs like sucralfate (SUC). These anti-acids have been shown to cause sensitization to food proteins via elevation of the gastric pH. The aim of this study was to assess the oral adjuvant properties of ALUM, alone or contained in SUC, in a BALB/c mouse model. METHODS: Mice were fed SUC plus ovalbumin (OVA) and compared with groups where ALUM or proton pump inhibitors (PPI) were applied as adjuvants. The humoral and cellular immune responses were assessed on antigen-specific antibody and cytokine levels. The in vivo relevance was investigated in skin tests. RESULTS: The highest OVA-specific immunoglobulin G1 (IgG1) and IgE antibody levels were found in mice fed with OVA/SUC, followed by OVA/ALUM-treated animals, indicating a T helper 2 (Th2) shift in both groups. Antibody levels in other groups revealed lower (OVA/PPI-group) or baseline levels (control groups). Positive skin tests confirmed an allergic response in anti-acid or adjuvant-treated animals. CONCLUSIONS: Our data show for the first time that ALUM acts as a Th2-adjuvant via the oral route. This suggests that orally applied SUC leads to an enhanced risk for food allergy, not only by inhibiting peptic digestion but also by acting as a Th2-adjuvant by its ALUM content.

A mimotope gene encoding the major IgE epitope of allergen Phl p 5 for epitope-specific immunization.

A gene vaccine based on a mammalian expression vector containing the sequence of a peptide mimotope of Phl p 5 was constructed. To test whether mimotope gene vaccines can induce allergen-specific antibody responses via molecular mimicry, BALB/c mice were immunized using the mimotope construct with or without a tetanus toxin T-helper epitope. Moreover, intradermal injection was compared to epidermal application via gene gun immunization. Immunization with both mimotope gene constructs elicited allergen-specific antibody responses. As expected, gene gun bombardment induced a Th2-biased immune response, typically associated with IgG1 and IgE antibody production. In contrast, intradermal injection of the vaccine triggered IgG2a antibody expression without any detectable IgE levels, thus biasing the immune response towards Th1. In an RBL assay, mimotope-specific IgG antibodies were able to prevent cross-linking of allergen-specific IgE by Phl p 5. A construct coding for the complete Phl p 5 induced T-cell activation, IFN-gamma and IL-4 production. In contrast, the mimotope-DNA construct being devoid of allergen-specific T-cell epitopes had no capacity to activate allergen-specific T cells. Taken together, our data show that it is feasible to induce blocking IgG antibodies with a mimotope-DNA construct when applied intradermally. Thus the mimotope-DNA strategy has two advantages: (1) the avoidance of IgE induction and (2) the avoidance of triggering allergen-specific T-lymphocytes. We therefore suggest that mimotope gene vaccines are potential candidates for epitope-specific immunotherapy of type I allergy.

Dose-dependent food allergy induction against ovalbumin under acid-suppression: a murine food allergy model.

BACKGROUND: Animal models are essential for analyzing the allergenic potential of food proteins and for investigating mechanisms underlying food allergy. Based on previous studies revealing acid-suppression medication as risk factor for food allergy induction, we aimed to establish a mouse model mimicking the natural route of sensitization in patients. METHODS: The effect of acid-suppressing medication on murine gastric pH was assessed by intragastric pH measurements after two injections of a proton pump inhibitor (PPI). To investigate dose-dependency, mice were fed different concentrations of ovalbumin (OVA; 0.2, 0.5, 1.0, 2.5 or 5.0mg) either with or without anti-ulcer medication. Additionally, different routes of exposure (i.p. vs. oral) were compared in a second immunization experiment. Sera were screened for OVA-specific antibody titers (IgG1, IgG2a and IgE) in ELISA and RBL assay. Clinical reactivity was evaluated by measuring rectal temperature after oral challenge and by type I skin tests. RESULTS: Two intravenous injections of PPI significantly elevated the gastric pH from 2.97 to 5.3. Only oral immunization with 0.2mg OVA under anti-acid medication rendered elevated IgG1, IgG2a and IgE titers compared to all other concentrations. Protein feeding alone altered antibody titers only marginally. Even though also i.p. immunizations induced high levels of specific IgE, only oral immunizations under anti-acids induced anaphylactic reactions evidenced by a significant decrease of body temperature. CONCLUSION: Only low-dosage ovalbumin feedings under anti-acid medication resulted in IgE mediated food allergy. Based on this knowledge we have established a suitable food allergy model for further investigations of food adverse reactions.

Vaccination strategies based on the mimotope concept.

Specific immunotherapies are in broad use for many diseases like allergies, cancer, autoimmune diseases or parasitic infections. Although clinical trials show successful application of these therapies, several disadvantages hinder the complete success. High production costs and repeated administrations represent the practical problems, while the possibly occurring side effects are the therapeutic troubles. To avoid these problems, the target specificity should be considered more intensely. Epitopes, the particular parts of antigens/allergens where they bind specific antibodies, are useful targets. To generate an epitope-specific vaccination, mimotopes can be identified via the biopanning technology. Mimotopes are small peptides mimicking the epitopes in the structural as well as in the immunological point of few. They are able to induce antigen-specific antibodies in active immunization form. These antibodies are directed against the natural antigen/allergen, and therefore they are able to block the outbreak of the diseases. Current research focuses on the development of mimotopes to achieve an epitope-specific induction of blocking antibodies, e.g. for allergy treatment. In cancer therapy, studies with mimotopes show successful interference with tumor cell growth in immunizations of mice. Also in the case of autoimmune diseases and parasitic infections this method was applied, targeting different molecules, which are key mediators in the disease mechanisms. Through the mimotope treatment via the specific antibody production, the disease symptoms could be hampered. This review gives an overview of the use of the mimotope concept and also of related therapeutic trials for the treatment of allergy, cancer, autoimmune and infectious diseases.

CD4+ T cells from mice with intestinal immediate-type hypersensitivity induce airway hyperreactivity.

BACKGROUND: A subset of food-allergic patients does not only respond clinically with symptoms in the gastro-intestinal tract but also with asthmatic reactions. OBJECTIVE: The aim of this study was to analyse whether CD4+ T cells from mice with intestinal immediate-hypersensitivity reactions to food allergen are involved in the development of experimental asthma. METHODS: BALB/c mice were intraperitoneally sensitized to ovalbumin (OVA), followed by repeated intra-gastric (i.g.) OVA challenges. Control animals were either sham-sensitized or sham-challenged with phosphate-buffered saline (PBS). Duodenum, jejunum, ileum and colon were histologically examined. CD4+ T cells from mesenteric lymph nodes were transferred from various donor groups into recipient mice that received either OVA or PBS aerosol challenges. Recipients were analysed by measurements of lung function using head-out body-plethysmography and examination of broncho-alveolar lavage and lung histology. RESULTS: The highest levels of OVA-specific IgE antibody levels were detected in OVA-sensitized and OVA-challenged mice. Throughout the lower intestinal tract, a marked infiltration with eosinophils was observed, and goblet cell numbers as well as goblet cell area were significantly increased. The villus/crypt ratio was decreased compared with controls. The transfer of CD4+ T cells from mesenteric lymph nodes of OVA-sensitized and OVA-challenged mice triggered airway hyperreactivity and eosinophilic airway inflammation in recipients aerosol challenged with OVA, but not with PBS. CONCLUSION: We conclude that CD4+ T cells from mesenteric lymph nodes of mice with allergen-induced immediate-type hypersensitivity reactions in the gut are able to transfer the phenotype of experimental asthma.

The impact of aluminium in acid-suppressing drugs on the immune response of BALB/c mice.

BACKGROUND: Recently we have shown that anti-acid drugs lead to an enhanced risk of food allergy. This may be due to hindered peptic digestion, caused by an elevation of the gastric pH. Additionally, it is known that aluminium-linked antigens lead to an increased probability of sensitization. OBJECTIVE: Our aim in this study was to show whether sucralfate promotes sensitization not only by preventing peptic digestion but also by acting as a T-helper type 2 (Th2) adjuvant. METHODS: To avoid the effect of sucralfate on the gastric pH and to show only the adjuvant effect, BALB/c mice were immunized on the parenteral route with codfish extract plus sucralfate, and control groups with aluminium hydroxide (alum) (Th2 adjuvant) or monophosphoryl lipid A (MPL) (Th1 adjuvant). Antigen-specific antibodies and cytokine levels were determined. The in vivo effect was investigated by intradermal skin tests. RESULTS: Codfish-specific high IgG1 and IgE antibody levels as well as elevated IL-4 and IL-5 levels in alum- and MPL-treated mice, but more importantly also in sucralfate-treated mice, indicated a Th2 shift. Positive skin tests confirmed this Th2 response. CONCLUSIONS: Our data show that parenterally applied sucralfate is able to induce a Th2 response probably due to the aluminium content. This indicates that orally applied sucralfate may lead to an enhanced risk of food allergy not only by inhibiting peptic digestion but also by acting as a Th2 adjuvant.

Quantitative analysis of Tenecteplase in rat plasma samples using LC-MS/MS as an alternative for ELISA.

An LC-MS/MS method has been developed for the quantitative determination of a protein drug (Tenecteplase; M(W) 58,777 Da) in rat plasma. The protein was digested with trypsin without prior clean-up of the plasma sample, without the use of a label nor internal standard. A limited validation was performed to assess the linearity, the sensitivity and the specificity of the method. In addition, the developed method was applied to the quantitative analysis of Tenecteplase in rat plasma samples originating from a single-dose study in rats.

Occupational sensitization to ribosome-inactivating proteins in researchers.

BACKGROUND: Ribosome-inactivating proteins (RIPs) are expressed in many plants. Because of their anti-infectious and anti-proliferative effects, intensive research is going on for applying these toxins in therapy against viral infections or malignancies. Recently, we demonstrated that type I allergy against RIPs from elderberry can occur. OBJECTIVE: Stimulated by our study, a group of RIP researchers reported that some of the employees had suspected allergy to RIPs. METHODS AND RESULTS: We tested their sera in ELISA on natural RIPs. Specific IgE in four subjects were found against dianthin30, gelonin, momordin, PAP-S, saporin, ricin and volkensin. In contrast, asparin and lychnin did not show any IgE binding. When separating extracts of plants containing the toxins in SDS-PAGE, RIPs appeared to be the predominant constituents. Interestingly, among the other plant proteins, they were exclusively recognized by IgE in immunoblot. RIPs derived from close botanical families share high sequence homologies. Nevertheless, in IgE inhibition experiments with human sera, cross-reactivity between RIPs also derived from non-related plants could be demonstrated. CONCLUSION: We conclude that sensitization and IgE induction to RIPs may occur upon exposure. This has to be considered when applying them in therapy against malignancies or viral infections.

Allergen-loaded biodegradable poly(D,L-lactic-co-glycolic) acid nanoparticles down-regulate an ongoing Th2 response in the BALB/c mouse model.

BACKGROUND AND OBJECTIVE: Biocompatible and biodegradable microparticles have gained interest as antigen delivery systems during the recent years. We investigated whether biodegradable poly(d,l-lactic-co-glycolic) acid (PLGA) nanospheres could be used as allergen vehicles for few-shot therapy of type I allergy. METHODS: The major birch pollen allergen Bet v 1 was encapsulated in PLGA nanospheres (PLGA-Bet v 1). We examined the antigenicity and the immune response to PLGA-Bet v 1 in a BALB/c mouse model. RESULTS: The antigenicity of Bet v 1 was largely unaffected by PLGA entrapment. When BALB/c mice were immunized subcutaneously with PLGA-Bet v 1, they formed allergen-specific IgG antibodies, but did not develop hypersensitivity to Bet v 1, as shown by type I skin tests. To evaluate their therapeutic potential, PLGA-Bet v 1 with or without Al(OH)3 or non-entrapped Bet v 1 with Al(OH)3 were used for single-shot treatment of sensitized mice. Both groups treated with PLGA-Bet v 1 developed high levels of Bet v 1-specific IgG2a antibodies (P<0.01), whereas IgG1 levels decreased significantly (P<0.01). Moreover, T cells from mice treated with PLGA-Bet v 1 showed IFN-gamma and IL-10 production. The synthesis of these cytokines was enhanced in the groups where Al(OH)3 had been added to the vaccine formulation. CONCLUSION: Allergen-loaded PLGA nanoparticles modulate an ongoing Th2 response in the BALB/c mouse model, as demonstrated by down-regulation of IgG1 and production of IFN-gamma and IL-10. Our data strongly suggest that PLGA nanospheres can advantageously be used for formulations of allergen extracts or allergen derivatives for the few-shot treatment of type I allergy.