IntroductionLipid transfer proteins (LTPs) are allergens found in a wide range of plant-foods. Specifically, Pru p 3, the major allergen of peach, is commonly responsible for severe allergic reactions. The need for new alternatives to conventional food allergy treatments, like restrictive diets, suggests allergen immunotherapy as a promising option. It has been demonstrated that sublingual immunotherapy (SLIT) with synthetic glycodendropeptides, such as D1ManPrup3, containing mannose and Pru p 3 peptides induced tolerance in mice and that the persistence of this effect depends on treatment dose (2nM or 5nM). Moreover, it produces changes associated with differential gene expression and methylation profile of dendritic cells, as well as phenotypical changes in regulatory T cells (Treg). However, there are no works addressing the study of epigenetic changes in terms of methylation in the cell subsets that sustain tolerant responses, Treg. Therefore, in this work, DNA methylation changes in splenic-Treg from Pru p 3 anaphylactic mice were evaluated.MethodsIt was performed by whole genome bisulphite sequencing comparing SLIT-D1ManPrup3 treated mice: tolerant (2nM D1ManPrup3), desensitized (5nM D1ManPrup3), and sensitized but not treated (antigen-only), with anaphylactic mice.ResultsMost of the methylation changes were found in the gene promoters from both SLIT-treated groups, desensitized (1,580) and tolerant (1,576), followed by the antigen-only (1,151) group. Although tolerant and desensitized mice showed a similar number of methylation changes, only 445 genes were shared in both. Remarkably, interesting methylation changes were observed on the promoter regions of critical transcription factors for Treg function like Stat4, Stat5a, Stat5b, Foxp3, and Gata3. In fact, Foxp3 was observed exclusively as hypomethylated in tolerant group, whereas Gata3 was only hypomethylated in the desensitized mice.DiscussionIn conclusion, diverse D1ManPrup3 doses induce different responses (tolerance or desensitization) in mice, which are reflected by differential methylation changes in Tregs.

IntroductionAllergen-specific immunotherapy (AIT) is applied as treatment to rise tolerance in patients with food allergies. Although AIT is thoroughly used, the underlying epigenetic events related to tolerant induction are still unknown. Thus, we aim to investigate epigenetic changes that could be related to tolerance in dendritic cells (DCs) from anaphylactic mice to lipid transfer proteins, Pru p 3, in the context of a sublingual immunotherapy (SLIT) with a glycodendropeptide (D1ManPrup3) that has demonstrated tolerant or desensitization responses depending on the treatment dose.MethodsChanges in DNA methylation in CpG context were determined comparing Sensitized (Antigen-only) animals and two groups receiving SLIT with the D1ManPrup3 nanostructure (D1ManPrup3-SLIT): Tolerant (2nM D1ManPrup3) and Desensitized (5nM D1ManPrup3), against anaphylactic animals. DNA from lymph nodes-DCs were isolated and then, Whole Genome Bisulphite Sequencing was performed to analyze methylation.ResultsMost differentially methylated regions were found on the area of influence of gene promoters (DMPRs). Compared to the Anaphylactic group, the highest value was found in Desensitized mice (n = 7,713 DMPRs), followed by Tolerant (n = 4,091 DMPRs) and Sensitized (n = 3,931 DMPRs) mice. Moreover, many of these epigenetic changes were found in genes involved in immune and tolerance responses (Il1b, Il12b, Il1a, Ifng, and Tnf) as shown by functional enrichment (DCs regulation, B cell-mediated immunity, and effector mechanisms).DiscussionIn conclusion, different doses of D1ManPrup3-SLIT induce different DNA methylation changes, which are reflected in the induction of distinct responses, tolerance, or desensitization.

Respiratory diseases are pathological conditions that affect airways, hampering breathing and causing high mortality. In particular, asthma and allergic rhinitis (AR) are two of the most common airway diseases that affect millions of people and have a high prevalence in childhood and adulthood. Asthma is a heterogeneous chronic inflammatory disease characterized by wheezing, chest tightness, shortness of breath, and cough. AR occurs with rhinorrhea, nasal congestion, and sneezing. Indeed, these pathologies share common physiopathological mechanisms such as airway hyperresponsiveness and similar immunopathology such as tissue eosinophilia and T-helper type 2 inflammation. Moreover, AR can be an important risk factor for suffering asthma. Thus, early diagnosis and effective treatment are crucial to improving the health and quality of life of these patients. Classical drugs such as corticosteroids have been used; however, in the last decades, efforts to improve treatments have increased, focusing on biological agents and specific allergen immunotherapy development. Moreover, more precise diagnostic tools have been elaborated, besides classical methods (medical history, physical examination, and pulmonary function tests), such as basophil activation test, and specific cellular and molecular biomarkers (microRNAs, sputum/blood eosinophils, IgE serum, and periostin levels). Therefore, in this review, we compile all these important issues for managing asthma and AR.

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