Vaccine against peanut allergy based on engineered Virus-Like-Particles displaying single major peanut allergens.
Background: Peanut allergy is a severe and increasingly frequent disease with high medical, psychosocial and economical burden for affected patients. A causal, safe and effective therapy is not available. Objective: We aimed to develop an immunogenic, protective and non-reactogenic vaccine candidate against peanut allergy based on Virus-like Particles (VLPs) coupled to single peanut allergens. Methods: To generate vaccine candidates, extracts of roasted peanut (Ara R) or the single allergens Ara h 1 or Ara h 2 were coupled to immunologically optimized Cucumber Mosaic Virus-derived VLPs (CuMVtt). BALB/c mice were sensitized intraperitoneally with peanut extract absorbed to Alum. Immunotherapy consisted of one single subcutaneous injection of CuMVtt coupled to Ara R, Ara h 1 or Ara h 2. Results: The vaccines CuMVtt-Ara R, CuMVtt-Ara h 1 and CuMVtt-Ara h 2 protected peanut sensitized mice against anaphylaxis after i.v. challenge with the whole peanut extract. Vaccines did not cause allergic reactions in sensitized mice. CuMVtt-Ara h 1 was able to induce specific IgG antibodies, diminished local reactions after skin-prick-tests and reduced the infiltration of the gastrointestinal tract by eosinophils and mast cells after oral challenge with peanut. The ability of CuMVtt-Ara h 1 to protect against challenge with the whole extract was mediated by IgG, as shown via passive IgG transfer. FcγRIIb was required for protection, indicating that immune-complexes with single allergens were able to block the allergic response against the whole extract, consisting of a complex allergen mixture. Conclusion: Our data suggest that vaccination using single peanut allergens displayed on CuMVtt may represent a novel and safe therapy against peanut allergy.
Real-world tree nut consumption in peanut-allergic individuals.
Background: Individuals with peanut allergy often avoid tree nuts, yet true rates of tree nut allergy in peanut-allergic individuals are as low as 7%. Objective: To examine tree nut sensitization patterns in peanut-allergic individuals, patient and family choice regarding tree nut consumption, and factors that influence consumption of tree nuts. Methods: All patients presenting for peanut allergy evaluation to an outpatient allergy office were included during a 4-month period. In addition to demographic information, sensitization to tree nuts and tree nut consumption were collected. Logistic regression was performed to generate odds ratios with 95% CIs in univariate and multivariate analyses for variables that predict tree nut consumption. Results: A total of 258 individuals with peanut allergy were enrolled. Ninety-five (36.8%) consumed all tree nuts ad libitum, 63 (24.4%) consumed some but not all tree nuts, and 100 (38.8%) consumed no tree nuts. Of the 100 electively avoiding all tree nuts, the most commonly reported reason was fear of cross-contact (50%). Although there was no difference between rates of sensitization between individual tree nuts (P = .056), cashew and pistachio had higher serum specific IgE levels compared with other tree nuts (P < .001). The tree nut most commonly consumed by peanut-allergic individuals was almond (P < .001). Consumption of foods with precautionary labeling was the strongest predictor of tree nut consumption in peanut allergic individuals (P < .001) CONCLUSION: Our data highlight the potential for safe introduction of tree nuts in peanut-allergic individuals and indicate that peanut-allergic individuals who consume foods with precautionary labeling are most likely to consume tree nuts.
Defining challenge-proven coexistent nut and sesame seed allergy: A prospective multicenter European study.
Background: Peanut, tree nut, and sesame allergies are responsible for most life-threatening food-induced allergic reactions. Rates of coexistent allergy between these foods have been from mostly retrospective studies that include only a limited number of tree nuts or were not based on oral food challenges. Objective: The Pronuts study is a multicenter European study (London, Geneva, and Valencia) assessing the challenge-proven rate of coexistent peanut, tree nut, and/or sesame seed allergy. Methods: Children aged 0 to 16 years with at least 1 confirmed nut or sesame seed allergy underwent sequential diagnostic food challenges to all other nuts and sesame seed. Results: Overall, the rate of coexistent peanut, tree nut, and sesame seed allergy was 60.7% (n = 74/122; 95% CI, 51.4% to 69.4%). Peanut allergy was more common in London, cashew and pistachio nut allergies were more common in Geneva, and walnut and pecan allergies were more common in Valencia. Strong correlations were found between cashew-pistachio, walnut-pecan, and walnut-pecan-hazelnut-macadamia clusters. Age (>36 months) and center (Valencia > Geneva > London) were associated with an increased odds of multiple nut allergies. By pursuing the diagnostic protocol to demonstrate tolerance to other nuts, participants were able to introduce a median of 9 nuts. Conclusion: We found a higher rate of coexistent nut and sesame seed allergies than previously reported. Performing sequential food challenges was labor intensive and could result in severe allergic reactions; however, it reduced dietary restrictions. Age was a significant predictor of multiple nut allergies, and thus the secondary spread of nut allergies occurred in older children.
Current perspectives on peanut allergy.
Peanut allergy is increasingly prevalent and for most patients is a life-long condition, with the potential to cause life-threatening reactions. Accurate diagnosis and appropriate management are essential to minimise risks due to accidental peanut exposure. Current management strategies focus on strict allergen avoidance and access to emergency medicines to treat potential reactions; however, active approaches are an area of intense research. Promising new methods of food allergen immunotherapy are set to change the approach to managing peanut allergic patients in the near future.
Prevention of Non-peanut Food Allergies.
Purpose of review: The purpose of this review article is to discuss the recent literature around methods of prevention of food allergies other than peanut allergy. Recent findings: While the most robust data to date exists for peanut, there are emerging studies suggesting a beneficial effect to early introduction of cooked egg, and cow's milk as well. While the literature is sparse for other allergens such as tree nuts, finned fish, and shellfish, the mechanism of sensitization is thought to be the same and no study to date has demonstrated a harm with allergenic introduction in the 4-6 months of age window (nor has there been level 1 evidence of benefit to delay of such allergens). This strategy is safe, and pre-emptive testing is not required prior to allergenic solid introduction. All allergenic solids should be introduced at around 6, but not before 4, months of age in infants at high risk.
High sorption efficiency for As (III) and As (V) from aqueous solutions using novel almond shell biochar.
Arsenic (As) presence in surface reservoirs and groundwater is considered as an extremely alarming issue around the globe. The objectives of the present study were to evaluate the sorption potential of almond shell (ALS) and almond shell biochar (ASB) based sorbents for the removal of As(III)/As(V) from As-contaminated aqueous solutions. The maximum As(III) sorption capacity of ALS and ASB were 4.6 and 4.86 mg g-1, respectively at an initial As concentration of 5 mg L-1, pH ∼ 7.2 and sorbent dose of 0.6 g L-1. Similarly, in case of As(V) the maximum sorption capacities were reported as 3.45 and 3.6 mg g-1 by ALS and ASB respectively. Almond shell biochar removed 10-25% higher As(III)/As(V) compared to the ALS. The isotherm modeling results revealed that both for As(III) and As(V), Langmuir model presented the suitable fit to the equilibrium data compared to other model showing the monolayer sorption to be a dominant sorption mechanism. The FTIR and XPS spectroscopy revealed that mostly -OH functional groups along with some other aromatic and/or aliphatic carbon- and oxygen-rich groups (CC-C, -C-H, CO) were responsible for As sorption by both sorbents. It is concluded that ASB can remove As, notably As(III) from water more efficiently compared to natural ALS. Overall, the results of this research reveal that biochar conversion of ALS can enhance the sorption capacity for As in contaminated waters such as drinking water and wastewater.
In Vitro Antioxidant Activity Optimization of Nut Shell (Carya Illinoinensis) by Extrusion Using Response Surface Methods.
The pecan (Carya illinoinensis) nut shell is an important byproduct of the food processing industry that has not been previously explored as an antioxidant compound. This work aims to study the effect of the extrusion temperature and screw speed on the moisture content, water and oil absorption index, water solubility index, color, phenolic compounds, condensed tannin compounds, and antioxidant activity of pecan nut shell extrudates. Extrusion variables were adjusted using a response surface methodology. Extrusion, performed at 70 °C and 150 rpm, almost doubled the concentration of polyphenols in the non-extruded shell and significantly increased radical scavenging activity. Compounds in extrudates, performed at 70 °C and 150 rpm, were quantified by high-performance liquid chromatography (HPLC) with a diode-array detector (DAD) and identified by liquid chromatography coupled with time-of-flight mass spectrometry (LC-MSD-TOF). Extrusion significantly increased most phenolic acid compounds, including gallic acid, ellagic acid pentose, ellagic acid, dimethyl ellagic acid rhamnoside, and dimethyl ellagic acid. The soluble fiber in extrudates was more than three-fold higher than in the control. Therefore, extrusion at 70 °C and 150 rpm increased the concentration of phenolic compounds, antioxidant activity, and total dietary and soluble fiber. Our findings support the notion that extruded pecan nut shell can be used in clean-label products and improve their nutraceutical value.
Characterization of Polyphenolic Compounds Extracted from Different Varieties of Almond Hulls (Prunus dulcis L.).
Ultrasound-assisted extraction (UAE) was applied as a pretreatment technique to improve the recovery of polyphenols from the almond hulls of four Tunisian and three Italian almond varieties, followed by the characterization with HPLC-DAD. The operating parameters (solid/liquid ratio, extraction time, and ethanol concentrations) were optimized using a Response Surface Methodology. A polynomial equation was calculated to describe the relationship between the operating parameters and dependent variables as total polyphenolic content (TPC) and antioxidant activity (RSA). A desirability function approach was used to determine the optimum conditions for operating parameters: a solid:solvent ratio of 2 g/100 mL, an extraction time of 13 min, and an ethanol concentration of 51.2%. Among the almond varieties, Pizzuta and Fakhfekh showed the highest polyphenol content and antioxidant activity. HPLC-DAD analysis of almond hull extracts confirmed that chlorogenic acid, catechin, and protocatechuic acid were the most important polyphenols in almond hull. The results highlighted that UAE could be an effective technique for the recovery of phenolic compounds from almond hull, thereby making this byproduct a promising source of compounds with potential applications in food and healthcare sectors.
Reducing atmosphere drying as a novel drying technique for preserving the sensorial and nutritional notes of foods.
Reducing atmosphere drying (RAD) was assayed as a novel technique for preserving the color and the nutritional fresh notes of apricot. A freeze, hot air and vacuum drying techniques were applied for a comparison purpose. The results showed that the apricot samples dried by both RADMIX and RADNITROGEN preserved better the fresh color notes while the freeze-drying was characterized by light and dully notes compared to a fresh sample. The total phenolic content significantly differed between fresh, RADMIX, RADAIR, hot air and vacuum with the highest value observed for both vacuum and hot air with 284.8 and 259.5 mg GAE 100 g-1 dm, respectively. DPPH inhibition activity was significantly similar for both fresh (or freeze drying) and each RADMIX, hot air and vacuum dried samples with 83.52, 76.3, 70.31, 67.86%, respectively, with the highest value attributed to RADMIX sample. The RAD-type dried samples (RADMIX, RADNITROGEN, RADAIR) possessed ABTS scavenging activity range of 68.74, 64.49 and 61.61 μmol TE g-1 dm respectively, which were close to that of the fresh sample (63.36 μmol TE g-1 dm) with the highest value attributed to RADMIX sample. The total flavonoid content was significantly similar between fresh (or freeze drying), vacuum, hot air and RADMIX samples with a range of 27.38, 24.25, 19.41 and 18.81 mg QE 100 g-1 dm, respectively, which exhibited an advantageous role of hydrogen in RADMIX system over both RADNITROGEN and RADAIR. For the first time, a technique based on the use of hydrogen in the drying atmosphere of a closed system was successfully proved for drying foods. This novel technique exhibits an opportunity for the food drying processors to produce dried foodstuffs with fresh color and nutritional notes.
FT-IR spectroscopy and Morphological study of functionalized cellulosic fibers: Evaluation of their dyeing properties using biological Pistacia vera hulls by-product extract.
The repulsion between cellulose and anionic entities could be overcome by imparting cationic sites on its structure. In this work, we studied the treatment of cotton fabric with different amounts of chitosan bio-polymer (0.0125-0.075%), dimethyl diallyl ammonium chloride and diallylamin co-polymer (1-5%), alum (0.5-20 g/L), and sodium chloride (2-40 g/L) in order to improve their dyeing behaviors with an ecological extract of Pistacia vera hulls by-products. The chemical modification of the cellulosic fibers was confirmed using Fourier Transform Infra-Red (FT-IR) and Scanning Electron Microscopy (SEM). The unmodified and modified cellulosic samples were, then, dyed with Pistacia vera extract. The dyeing characteristics were assessed through the measurements of the color coordinates and the color strength. Results showed that the dyeing performance followed the order: Cotton-dimethyl diallyl ammonium chloride and diallylamin co-polymer (K/S = 9.6) > Cotton-Chitosan (K/S = 8.97) > Cotton-Alum (8.84) > Cotton-NaCl (K/S = 6.06) > Untreated cotton (K/S = 1.98). All dyed samples exhibited good fastness to washing, rubbing and light. Overall, it has shown in this study that the functionalization of cellulose structure could greatly improve its dyeing behavior depending on the cationic sites number.