T-cell responses to allergens

Comparative study on the alleviating effect of neohesperidin dihydrochalcones and its synthetic precursor neohesperidin on ovalbumin-induced food allergy

The biological activities of natural flavonoids are structure-dependent. To investigate the structure-dependent activities of neohesperidin dihydrochalcone (NHDC) and neohesperidin (NH), which have the same basic skeletal structure, we systematically compared their roles in alleviating ovalbumin-induced food allergies in mice. Our results indicate that NHDC is superior to NH in ameliorating allergic symptoms, especially in restoring T helper 1 and T helper 2 cells (Th1 and Th2, respectively)balance and inhibiting splenic NOTCH/nuclear factor kappa-B (NF-κB) activation by enhancing binding to Hes1, which was validated by molecular docking. Both compounds increased the abundance of beneficial gut microbiota (e.g., Lactobacillus). Still, the dihydrochalcone portion of NHDC possessed superior intestinal barrier repair and immunomodulatory effects, synergizing anti-inflammatory and microbiota modulatory effects. These results provide new insights into the structure-dependent activity of natural flavonoids in treating food allergies.

Rhinovirus as a driver of airway T cell dynamics in children with treatment-refractory recurrent wheeze

Severe asthma in children is notoriously difficult to treat, and its immunopathogenesis is complex. In particular, the contribution of T cells and relationships to antiviral immunity remain enigmatic. Here, we coupled deep phenotyping with machine learning methods to elucidate the dynamics of T cells in the lower airways of children with treatment-refractory recurrent wheeze, and examine rhinovirus (RV) as a driver. Our strategy revealed a T cell landscape dominated by type 1 and type 17 CD8+ signatures. Interrogation of phenotypic relationships coupled with trajectory mapping identified T cell migratory and differentiation pathways spanning the blood and airways that culminated in tissue residency, and involved transitions between type 1 and type 17 tissue-resident types. These dynamics were reflected in cytokine polyfunctionality. Use of machine learning tools to cross-compare T cell populations that were enriched in the airways of RV-positive children with those induced in the blood following experimental RV challenge precisely pinpointed RV-responsive signatures that contributed to T cell migratory and differentiation pathways. Despite their rarity, these signatures were also detected in the airways of RV-negative children. Together, our results underscore the aberrant nature of type 1 immunity in the airways of children with recurrent wheeze, and implicate an important viral trigger as a driver.

Rhinovirus as a Driver of Airway T-Cell Dynamics in Children with Severe Asthma

Severe asthma in children is notoriously difficult to treat, and its immunopathogenesis is complex. In particular, the contribution of T cells and relationships to anti-viral immunity, remain enigmatic. Here, we coupled deep phenotyping with machine learning methods to resolve the dynamics of T cells in the diseased lower airways, and examined rhinovirus (RV) as a driver. Our strategy revealed a T-cell landscape dominated by type 1 and type 17 CD8+ signatures. Interrogation of phenotypic relationships coupled with trajectory mapping identified T-cell migratory and differentiation pathways spanning the blood and airways that culminated in tissue residency, and included transitions between type 1 and type 17 tissue-resident types. These T-cell dynamics were reflected in cytokine polyfunctionality in situ . Use of machine learning to cross-compare T-cell populations that were enriched in the airways of RV-positive children with those induced in the blood after RV challenge in an experimental infection model, precisely pinpointed RV-responsive signatures that mapped to T-cell differentiation pathways. Despite their rarity, these signatures were detected in the airways of uninfected children. Together, our results underscore the aberrant nature of type 1 immunity in the airways of children with severe asthma, and implicate an important viral trigger as a driver.

A mutation in Themis contributes to anaphylaxis severity following oral peanut challenge in CC027 mice

BACKGROUND

The development of peanut allergy is due to a combination of genetic and environmental factors, although specific genes have proven difficult to identify. Previously, we reported that peanut-sensitized Collaborative Cross strain CC027/GeniUnc (CC027) mice develop anaphylaxis upon oral challenge to peanut, in contrast to C3H/HeJ (C3H) mice.

OBJECTIVE

This study aimed to determine the genetic basis of orally induced anaphylaxis to peanut in CC027 mice.

METHODS

A genetic mapping population between CC027 and C3H mice was designed to identify the genetic factors that drive oral anaphylaxis. A total of 356 CC027xC3H backcrossed mice were generated, sensitized to peanut, then challenged to peanut by oral gavage. Anaphylaxis and peanut-specific IgE were quantified for all mice. T-cell phenotyping was conducted on CC027 mice and 5 additional Collaborative Cross strains.

RESULTS

Anaphylaxis to peanut was absent in 77% of backcrossed mice, with 19% showing moderate anaphylaxis and 4% having severe anaphylaxis. There were 8 genetic loci associated with variation in response to peanut challenge-6 associated with anaphylaxis (temperature decrease) and 2 associated with peanut-specific IgE levels. There were 2 major loci that impacted multiple aspects of the severity of acute anaphylaxis, at which the CC027 allele was associated with worse outcome. At one of these loci, CC027 has a private genetic variant in the Themis gene. Consistent with described functions of Themis, we found that CC027 mice have more immature T cells with fewer CD8+, CD4+, and CD4+CD25+CD127- regulatory T cells.

CONCLUSIONS

Our results demonstrate a key role for Themis in the orally reactive CC027 mouse model of peanut allergy.

Construction by artificial intelligence and immunovalidation of hypoallergenic mite allergen Der f 36 vaccine

Background

The house dust mite (HDM) is widely recognized as the most prevalent allergen in allergic diseases. Allergen-specific immunotherapy (AIT) has been successfully implemented in clinical treatment for HDM. Hypoallergenic B-cell epitope-based vaccine designed by artificial intelligence (AI) represents a significant progression of recombinant hypoallergenic allergen derivatives.

Method

The three-dimensional protein structure of Der f 36 was constructed using Alphafold2. AI-based tools were employed to predict B-cell epitopes, which were subsequently verified through IgE-reaction testing. Hypoallergenic Der f 36 was then synthesized, expressed, and purified. The reduced allergenicity was assessed by enzyme-linked immunosorbent assay (ELISA), immunoblotting, and basophil activation test. T-cell response to hypoallergenic Der f 36 and Der f 36 was evaluated based on cytokine expression in the peripheral blood mononuclear cells (PBMCs) of patients. The immunogenicity was evaluated and compared through rabbit immunization with hypoallergenic Der f 36 and Der f 36, respectively. The inhibitory effect of the blocking IgG antibody on the specific IgE-binding activity and basophil activation of Der f 36 allergen was also examined.

Results

The final selected non-allergic B-cell epitopes were 25-48, 57-67, 107-112, 142-151, and 176-184. Hypoallergenic Der f 36 showed significant reduction in IgE-binding activity. The competitive inhibition of IgE-binding to Der f 36 was investigated using the hypoallergenic Der f 36, and only 20% inhibition could be achieved, which is greatly reduced when compared with inhibition by Der f 36 (98%). The hypoallergenic Der f 36 exhibited a low basophil-stimulating ratio similar to that of the negative control, and it could induce an increasing level of IFN-γ but not Th2 cytokines IL-5 and IL-13 in PBMCs. The vaccine-specific rabbit blocking IgG antibodies could inhibit the patients' IgE binding and basophil stimulation activity of Derf 36.

Conclusion

This study represents the first application of an AI strategy to facilitate the development of a B-cell epitope-based hypoallergenic Der f 36 vaccine, which may become a promising immunotherapy for HDM-allergic patients due to its reduced allergenicity and its high immunogenicity in inducing blocking of IgG.

A mutation in Themis contributes to peanut-induced oral anaphylaxis in CC027 mice

Background

The development of peanut allergy is due to a combination of genetic and environmental factors, although specific genes have proven difficult to identify. Previously, we reported that peanut-sensitized CC027/GeniUnc (CC027) mice develop anaphylaxis upon oral challenge to peanut, unlike C3H/HeJ (C3H) mice.

Objective

To determine the genetic basis of orally-induced anaphylaxis to peanut in CC027 mice.

Methods

A genetic mapping population between CC027 and C3H mice was designed to identify the genetic factors that drive oral anaphylaxis. A total of 356 CC027xC3H backcrossed mice were generated, sensitized to peanut, then challenged to peanut by oral gavage. Anaphylaxis and peanut-specific IgE were quantified for all mice. T-cell phenotyping was conducted on CC027 and five additional CC strains.

Results

Anaphylaxis to peanut was absent in 77% of backcrossed mice, with 19% showing moderate anaphylaxis, and 4% having severe anaphylaxis. A total of eight genetic loci were associated with variation in response to peanut challenge, six associated with anaphylaxis (temperature decrease) and two associated with peanut-specific IgE levels. There were two major loci that impacted multiple aspects of the severity of acute anaphylaxis, at which the CC027 allele was associated with worse outcome. At one of these loci, CC027 has a private genetic variant in the Themis (thymocyte-expressed molecule involved in selection) gene. Consistent with Themis' described functions, we found that CC027 have more immature T cells with fewer CD8+, CD4+, and CD4+CD25+CD127- regulatory T cells.

Conclusion

Our results demonstrate a key role for Themis in the orally-reactive CC027 mouse model of peanut allergy.

Immunization with a Pneumococcal pep27 Mutant Strain Alleviates Atopic Dermatitis through the Upregulation of Regulatory T-Cell Activity and Epithelial Barrier Function and Suppressing TSLP Expression

Atopic dermatitis (AD) is an inflammatory disease driven in part by type 2 helper T (Th2) cytokines and skin barrier disruption alleviating the entry of allergens. Thymic stromal lymphopoietin (TSLP), an epithelial cell‒derived cytokine, is known to aggravate AD symptoms by activating Th2. In addition, regulatory T cells (Tregs) inhibit inflammatory cells such as Th2. However, the relationship between TSLP and Tregs in AD is unclear. A murine dermatitis model was induced by applying oxazolone to the ear skin of mice. Prophylactic and therapeutic responses were analyzed by immunizing mice intranasally with a pneumococcal pep27 mutant (Δpep27 mutant), attenuated strain by reducing the virulence of a pathogen. Intranasal immunization with a pneumococcal pep27 mutant could elicit anti-inflammatory Treg-relevant factors and epithelial barrier genes (loricrin, involucrin, filaggrin, and small proline-rich repeat proteins). Thus, pneumococcal pep27-mutant immunization suppressed epidermal collapse, IgE, TSLP, and upregulation of Th2 expression by upregulating Treg activity. In contrast, Treg inhibition aggravated AD symptoms through the upregulation of TSLP and Th2 and the repression of epithelial barrier function compared with that of the noninhibited pneumococcal Δpep27-mutant group. Taken together, immunization with pneumococcal Δpep27 mutant upregulated Treg and epithelial barrier function and inhibited TSLP and Th2 to relieve AD symptoms.

Evolutionary Biology and Gene Editing of Cat Allergen, Fel d 1

Allergy to domestic cat affects up to 15% of the population, and sensitization to cat allergen is associated with asthma. Despite the pervasiveness of cat allergic disease, current treatments have limited impact. Here, we present a bioinformatics analysis of the major cat allergen, Fel d 1, and demonstrate proof of principle for CRISPR gene editing of the allergen. Sequence and structural analyses of Fel d 1 from 50 domestic cats identified conserved coding regions in genes CH1 and CH2 suitable for CRISPR editing. Comparative analyses of Fel d 1 and orthologous sequences from eight exotic felid species determined relatively low-sequence identities for CH1 and CH2, and implied that the allergen may be nonessential for cats, given the apparent lack of evolutionary conservation. In vitro knockouts of domestic cat Fel d 1 using CRISPR-Cas9 yielded editing efficiencies of up to 55% and found no evidence of editing at predicted potential off-target sites. Taken together, our data indicate that Fel d 1 is both a rational and viable candidate for gene deletion, which may profoundly benefit cat allergy sufferers by removing the major allergen at the source.

Allergic rhinitis, allergic contact dermatitis and disease comorbidity belong to separate entities with distinct composition of T-cell subsets, cytokines, immunoglobulins and autoantibodies

Background

Allergic rhinitis (AR) and allergic contact dermatitis (ACD) are prevalent allergic diseases and have significant impacts on patients’ daily life. Despite many studies on AR or ACD have been conducted separately, little is known about the immune responses in patients of AR combined with ACD and the interplay between AR and ACD. Our study compared various aspects of immune elements in patients with AR or/and ACD, aiming to characterize the immune responses in AR, ACD, and AR combined with ACD.

Methods

A total of 57 patients diagnosed with AR or/and ACD and 28 healthy volunteers were included. AR patients were further divided into seasonal AR (SAR) and perennial AR (PAR). All subjects’ blood samples were taken to assess the concentration of immunoglobulins, complement C3, C4, autoantibodies and cytokines in serum by immunoturbidimetry, ELISA or Luminex200 platform. Peripheral blood mononuclear cells (PBMCs) were subjected to the analysis of lymphocyte subpopulations by flow cytometry.

Results

It indicated that AR disease caused elevated levels of IgE, IgA, IgG, IgG4, as well as IL-4, IL-15, IL-8 and IL-6 in serum. AR patients possessed a decreased CD4/CD8 ratio and an increased proportion of memory CD4 + T-cell subset, with a skewed Th2 response and an enhanced CD8 + T-cell activation. Compared with patients with sole AR or ACD condition, AR + ACD patients presented with a significantly increased proportion of memory CD8 + T-cell subset and were prone to autoimmune disorders as indicated by the increased autoantibodies. The immune elements in patients with ACD only were least affected compared with those in other conditions. Additionally, seasonal or perennial AR patients exhibited different cytokine profiles and proportions of memory T-cell subsets.

Conclusions

In this study, we illuminated the respective characteristics of immune responses in AR, ACD, and AR combined with ACD. Meanwhile, we discovered that the PAR and SAR patients possessed different cytokine profiles and T-cell compartments. It suggested that these allergic conditions belong to different disease entities. Characterizing the detailed immune changes in these allergic diseases would help to develop proper treatments targeting particular immune elements in different allergic diseases.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13223-022-00646-6.

Caspase-11 regulates lung inflammation in response to house dust mites

Asthma is an inflammatory lung disorder characterized by mucus hypersecretion, cellular infiltration, and bronchial hyper-responsiveness. House dust mites (HDM) are the most prevalent cause of allergic sensitization. Canonical and noncanonical inflammasomes are multiprotein complexes that assemble in response to pathogen or danger-associated molecular patterns (PAMPs or DAMPs). Murine caspase-11 engages the noncanonical inflammasome. We addressed the role of caspase-11 in mediating host responses to HDM and subsequent allergic inflammation using caspase-11-/- mice, which lack caspase-11 while express caspase-1. We found that HDM induce caspase-11 expression in vitro. The presence of IL-4 and IL-13 promote caspase-11 expression. Additionally, caspase-11-/- macrophages show reduced release of IL-6, IL-12, and KC, and express lower levels of costimulatory molecules (e.g., CD40, CD86 and MHCII) in response to HDM stimulation. Notably, HDM sensitization of caspase-11-/- mice resulted in similar levels of IgE responses and hypothermia in response to nasal HDM challenge compared to WT. However, analysis of cell numbers and cytokines in bronchiolar alveolar lavage fluid (BALF) and histopathology of representative lung segments demonstrate altered inflammatory responses and reduced neutrophilia in the airways of the caspase-11-/- mice. These findings indicate that caspase-11 regulates airway inflammation in response to HDM exposure.

A Novel Germline Heterozygous BCL11B Variant Causing Severe Atopic Disease and Immune Dysregulation

B-cell lymphoma/leukemia 11B (BCL11B) is a C2H2 zinc finger transcription factor that is critically important for regulating the development and function of a variety of systems including the central nervous system, the skin, and the immune system. Germline heterozygous variants are associated with a spectrum of clinical disorders, including severe combined immunodeficiency as well as neurological, craniofacial, and dermal defects. Of these individuals, ~50% present with severe allergic disease. Here, we report the detailed clinical and laboratory workup of one of the most severe BCL11B-dependent atopic cases to date. Leveraging a zebrafish model, we were able to confirm a strong T-cell defect in the patient. Based on these data, we classify germline BCL11B-dependent atopic disease as a novel primary atopic disorder.

Programmable DNA-augmented hydrogels for controlled activation of human lymphocytes

Contractile forces within the planar interface between T cell and antigen-presenting surface mechanically stimulate T cell receptors (TCR) in the mature immune synapses. However, the origin of mechanical stimulation during the initial, i.e., presynaptic, microvilli-based TCR activation in the course of immune surveillance remains unknown and new tools to help address this problem are needed. In this work, we develop nucleic acid nanoassembly (NAN)-based technology for functionalization of hydrogels using isothermal toehold-mediated reassociation of RNA/DNA heteroduplexes. Resulting platform allows for regulation with NAN linkers of 3D force momentum along the TCR mechanical axis, whereas hydrogels contribute to modulation of 2D shear modulus. By utilizing different lengths of NAN linkers conjugated to polyacrylamide gels of different shear moduli, we demonstrate an efficient capture of human T lymphocytes and tunable activation of TCR, as confirmed by T-cell spreading and pY foci.

Current Understanding of the Immunomodulatory Activities of High-Density Lipoproteins

Lipoproteins interact with immune cells, macrophages and endothelial cells - key players of the innate and adaptive immune system. High-density lipoprotein (HDL) particles seem to have evolved as part of the innate immune system since certain HDL subspecies contain combinations of apolipoproteins with immune regulatory functions. HDL is enriched in anti-inflammatory lipids, such as sphingosine-1-phosphate and certain saturated lysophospholipids. HDL reduces inflammation and protects against infection by modulating immune cell function, vasodilation and endothelial barrier function. HDL suppresses immune cell activation at least in part by modulating the cholesterol content in cholesterol/sphingolipid-rich membrane domains (lipid rafts), which play a critical role in the compartmentalization of signaling pathways. Acute infections, inflammation or autoimmune diseases lower HDL cholesterol levels and significantly alter HDL metabolism, composition and function. Such alterations could have a major impact on disease progression and may affect the risk for infections and cardiovascular disease. This review article aims to provide a comprehensive overview of the immune cell modulatory activities of HDL. We focus on newly discovered activities of HDL-associated apolipoproteins, enzymes, lipids, and HDL mimetic peptides.

A study of the association of cognitive abilities and emotional function with allergic disorders in young women

Background

Allergic disorders may have a bidirectional causal relationship with mental disorders. In this cross-sectional study, we aimed to assess the associations between cognitive abilities and emotional function tests and quality of life with the presence of allergic disease in young women.

Methods

A diagnosis of allergic disorders, comprising allergic rhinitis (AR), asthma and atopic dermatitis (AD), was confirmed by a specialist in allergy. The presence and severity of depression, anxiety, stress, insomnia and sleepiness were evaluated using validated questionnaires. Cognitive abilities and quality of life were assessed using standard instruments.

Results

Among 181 female young participants, the prevalence of AR, asthma and AD were 26.5%, 2.8%, and 14.9% respectively. The AR group had higher scores than the non-AR group for depression, anxiety, insomnia, and lower scores for physical and mental health-related quality of life. Moreover, the AD cases had higher scores on the depression and stress scale compared to those without it (p < 0.05). Asthmatic patients also had significantly higher insomnia severity and lower physical health-related quality of life than non-asthmatic.

Conclusion

There was a high prevalence of psychological/psychiatric disorders that included: anxiety, and sleep problems among allergic women, and a reduced quality of life that may be associated with it.

l-Arabinose Attenuates Gliadin-Induced Food Allergy via Regulation of Th1/Th2 Balance and Upregulation of Regulatory T Cells in Mice

Gliadins are the main cause of wheat allergies, and the prevalence of gliadin allergy has increased in many countries. l-Arabinose, a kind of plant-specific five-carbon aldose, possesses beneficial effects on food allergy to gliadins. This study investigated the antiallergic activities and underlying mechanisms of l-arabinose in a wheat gliadin-sensitized mouse model. BALB/c mice were sensitized to gliadin by intraperitoneal injections with gliadin followed by being given a gliadin challenge. l-arabinose-treated mice exhibited a marked reduction in the productions of total immunoglobulin E (IgE), gliadin-specific IgE, gliadin-specific IgG1, and histamine, with an increase in IgG2a level as compared with gliadin-sensitized mice. Beside that, a significant decrease in Th2-related cytokine level, IL-4, and an increase in Th1-related cytokine level, IFN-γ, in the serum and splenocytes were observed after treatment with l-arabinose. l-Arabinose treatment also improved the imbalance of Th1/Th2 immune response on the basis of the expression levels of related cytokines and key transcription factors in the small intestine and spleen of sensitized mice. In addition, gliadin-induced intestinal barrier impairment was blocked by l-arabinose treatment via regulation of TJ proteins and suppression of p38 MAPK and p65 NF-κB inflammation signaling pathways. Notably, the results confirmed that l-arabinose treatment increased CD4⁺ Foxp3⁺ T cell populations and Treg-related factors associated with increased expression of IL-2 and activation of STAT5 in gliadin-sensitized mice. In conclusion, l-arabinose attenuated the gliadin-induced allergic symptoms via maintenance of Th1/Th2 immune balance and regulation of Treg cells in a gliadin-induced mouse model, suggesting l-arabinose could be used as a promising agent to alleviate gliadin allergy.

DNA vaccines and recombinant allergens with reduced allergenic activity treat allergies

This review is intended to familiarize readers with major novel directions of developing allergy vaccines, their structure, as well as the mechanisms of forming a new immunological response in the course of the treating immunoglobulin E (IgE)-mediated allergic diseases. Currently, science offers a huge variety of new experimental forms of recombinant allergens with reduced allergenic activity and increased immunogenicity, or vice-versa, immune tolerance. Often, the mechanisms of their effect on the immune system are not fully understood. Scientific publications, including reviews covering this topic, allowed us identifying top priority areas in the development of allergy vaccines: recombinant hypoallergenic allergen derivatives, T cell epitope-based allergy vaccines, and B cell epitope-based allergy vaccines. In addition, the review discusses use of deoxyribonucleic acid (DNA) vaccines. Immunotherapy with DNA vaccines is the newest and least studied method of treating allergic diseases.

Hypersensitivities following allergen antigen recognition by unconventional T cells

Conventional T cells recognise protein-derived antigens in the context of major histocompatibility complex (MHC) class Ia and class II molecules and provide anti-microbial and anti-tumour immunity. Conventional T cells have also been implicated in type IV (also termed delayed-type or T cell-mediated) hypersensitivity reactions in response to protein-derived allergen antigens. In addition to conventional T cells, subsets of unconventional T cells exist, which recognise non-protein antigens in the context of monomorphic MHC class I-like molecules. These include T cells that are restricted to the cluster of differentiation 1 (CD1) family members, known as CD1-restricted T cells, and mucosal-associated invariant T cells (MAIT cells) that are restricted to the MHC-related protein 1 (MR1). Compared with conventional T cells, much less is known about the immune functions of unconventional T cells and their role in hypersensitivities. Here, we review allergen antigen presentation by MHC-I-like molecules, their recognition by unconventional T cells, and the potential role of unconventional T cells in hypersensitivities. We also speculate on possible scenarios of allergen antigen presentation by MHC-I-like molecules to unconventional T cells, the hallmarks of such responses, and the expected frequencies of hypersensitivities within the human population.

Repertoire-scale determination of class II MHC peptide binding via yeast display improves antigen prediction

CD4⁺ helper T cells contribute important functions to the immune response during pathogen infection and tumor formation by recognizing antigenic peptides presented by class II major histocompatibility complexes (MHC-II). While many computational algorithms for predicting peptide binding to MHC-II proteins have been reported, their performance varies greatly. Here we present a yeast-display-based platform that allows the identification of over an order of magnitude more unique MHC-II binders than comparable approaches. These peptides contain previously identified motifs, but also reveal new motifs that are validated by in vitro binding assays. Training of prediction algorithms with yeast-display library data improves the prediction of peptide-binding affinity and the identification of pathogen-associated and tumor-associated peptides. In summary, our yeast-display-based platform yields high-quality MHC-II-binding peptide datasets that can be used to improve the accuracy of MHC-II binding prediction algorithms, and potentially enhance our understanding of CD4⁺ T cell recognition.

Identifying peptides that can bind major histocompatibility complex II (MHC-II) is important for our understanding of T cell immunity and specificity. Here the authors present a yeast-display library screening approach that identifies more potential binders than various reported algorithms to help expand our understanding for antigen presentation.

Fig (Ficus carica L.) leaf tea suppresses allergy by acceleration disassembly of IgE-receptor complexes

In this study, I investigated the allergy suppressive effect of tea made from fig (Ficus carica L.) leaves. In the rat basophil cell line RBL-2H3, degranulation was significantly suppressed by treatment with fig tea at the same time as addition of IgE antibodies (sensitization). IgE bound to the cell surface was liberated in the medium depending on the treatment time with fig tea. Therefore, it was suggested that the mechanism of action of fig tea is promotion of dissociation of IgE from FcεRI receptors. Such a mechanism is novel in food materials. On oral administration to mice, fig tea showed an inhibitory effect on allergic dermatitis. Furthermore, in tests using an atopic dermatitis model in NC/Nga mice, continued administration of fig tea suppressed symptom exacerbation after antigen administration.Abbreviations: AD: atopic dermatitis; β-Hex: β-hexosaminidase; FCM: flow cytometory; OA: oral administration; TA: transdermal administration.

Lamiaceae: An Insight on Their Anti-Allergic Potential and Its Mechanisms of Action

The prevalence of allergic diseases such as asthma, allergic rhinitis, food allergy and atopic dermatitis has increased dramatically in recent decades. Conventional therapies for allergy can induce undesirable effects and hence patients tend to seek alternative therapies like natural compounds. Considering the fact above, there is an urgency to discover potential medicinal plants as future candidates in the development of novel anti-allergic therapeutic agents. The Lamiaceae family, or mint family, is a diverse plant family which encompasses more than 7,000 species and with a cosmopolitan distribution. A number of species from this family has been widely employed as ethnomedicine against allergic inflammatory skin diseases and allergic asthma in traditional practices. Phytochemical analysis of the Lamiaceae family has reported the presence of flavonoids, flavones, flavanones, flavonoid glycosides, monoterpenes, diterpenes, triterpenoids, essential oil and fatty acids. Numerous investigations have highlighted the anti-allergic activities of Lamiaceae species with their active principles and crude extracts. Henceforth, this review has the ultimate aim of compiling the up-to-date (2018) findings of published scientific information about the anti-allergic activities of Lamiaceae species. In addition, the botanical features, medicinal uses, chemical constituents and toxicological studies of Lamiaceae species were also documented. The method employed for data collection in this review was mainly the exploration of the PubMed, Ovid and Scopus databases. Additional research studies were obtained from the reference lists of retrieved articles. This comprehensive summarization serves as a useful resource for a better understanding of Lamiaceae species. The anti-allergic mechanisms related to Lamiaceae species are also reviewed extensively which aids in future exploration of the anti-allergic potential of Lamiaceae species.

Functional Role of Probiotics and Prebiotics on Skin Health and Disease

Scientific and commercial interest of probiotics, prebiotics and their effect on human health and disease has increased in the last decade. The aim of this review article is to evaluate the role of pro- and prebiotics on the normal function of healthy skin as well as their role in the prevention and therapy of skin disease. Lactobacilli and Bifidobacterium are the most commonly used probiotics and thought to mediate skin inflammation, treat atopic dermatitis (AD) and prevent allergic contact dermatitis (ACD). Probiotics are shown to decolonise skin pathogens (e.g., P. aeruginosa, S. aureus, A. Vulgaris, etc.) while kefir is also shown to support the immunity of the skin and treat skin pathogens through the production of antimicrobial substances and prebiotics. Finally, prebiotics (e.g., Fructo-oligosaccharides, galacto-oligosaccharides and konjac glucomannan hydrolysates) can contribute to the treatment of diseases including ACD, acne and photo aging primarily by enhancing the growth of probiotics.

Enhanced sensitivity of capture IgE‑ELISA based on a recombinant Der f 1/2 fusion protein for the detection of IgE antibodies targeting house dust mite allergens

The detection of allergen‑specific immunoglobulin (Ig)E is an important method for the diagnosis of IgE‑mediated allergic diseases. The sensitivity of the indirect IgE‑ELISA method against allergen extracts is limited by interference from high IgG titers and low quantities of effectual allergen components in extracts. To overcome these limitations, a novel capture IgE‑ELISA based on a recombinant Der f 1/Der f 2 fusion protein (rDer f 1/2) was developed to enhance the sensitivity to IgEs that bind allergens from the house dust mite (HDM) species Dermatophagoides farina. pET28‑Der f 1/2 was constructed and expressed in Escherichia coli BL21 (DE3) pLysS. The purified fusion protein was evaluated by IgE western blotting, IgE dot blotting and indirect IgE‑ELISA. Capture‑ELISA was performed by coating wells with omalizumab and incubating in series with sera, biotinylated Der f 1/2, horseradish peroxidase‑conjugated streptavidin and 3,3,5,5‑tetramethylbenzidine. The relative sensitivities of indirect‑ELISA and capture‑ELISA for HDM allergen‑specific IgE binding were determined; sera from non‑allergic individuals were used as the control group. rDer f 1/2 was expressed in the form of inclusion bodies comprising refolded protein, which were then purified. It exhibited increased IgE‑specific binding (24/28, 85.8%) than rDer f 1 (21/28, 75.0%) or rDer f 2 (22/28, 78.6%) with HDM‑allergic sera. Furthermore, in a random sample of HDM‑allergic sera (n=71), capture‑ELISA (71/71, 100%) was more sensitive than indirect‑ELISA (68/71, 95.8%) for the detection of HDM‑specific IgEs (P<0.01), indicating that this novel method may be useful for the diagnosis of HDM allergy.

Two polysaccharides from Porphyra modulate immune homeostasis by NF-κB-dependent immunocyte differentiation

Porphyra polysaccharides possess multiple pharmacological activities, such as immunoregulatory, anti-tumor and anti-inflammatory effects, but the specific underlying mechanisms are not fully understood.

A Probiotic Mixture Regulates T Cell Balance and Reduces Atopic Dermatitis Symptoms in Mice

Atopic dermatitis (AD) is a chronic inflammatory skin disorder with a complex etiology involving the immune response. Recent studies have demonstrated the role of certain probiotics in the treatment and prevention of AD. However, the mechanism by which these probiotics regulate the immune system remains unclear. In this study, we examined the immunomodulatory capacity of Duolac ATP, a mixed formulation of probiotics, both in vitro and in vivo. Results showed that the expression of programmed death-ligand 1(PD-L1) was significantly upregulated on bone marrow-derived dendritic cells (BMDCs) treated with Duolac ATP. Furthermore, the anti-inflammatory cytokines IL-10 and TGF-beta were both upregulated when BMDCs were treated with Duolac ATP. The percentage of proliferated regulatory T cells (Tregs) was enhanced when CD4⁺ T cells were co-cultured with Duolac ATP-treated BMDCs on plates coated with anti-CD3/CD28 antibodies. Intriguingly, IL-10 secretion from CD4⁺ T cells was also observed. The AD symptoms, histologic scores, and serum IgE levels in AD mice were significantly decreased after oral treatment with Duolac ATP. Moreover, the Th1-mediated response in AD-induced mice treated with oral Duolac ATP showed upregulation of IL-2 and IFN-gamma as well as of downstream signaling molecules T-bet, STAT-1, and STAT-4. Conversely, Duolac ATP suppressed Th2 and Th17 responses in AD-like mice, as evidenced by the downregulation of GATA-3, C-maf, IL-4, IL-5, and IL-17. Additionally, Duolac ATP increased the number of Tregs found at Peyer’s patches (PP) in treated AD mice. These results suggest that Duolac ATP modulates DCs to initiate both Th1 and Treg responses in AD mice. Thus, Duolac ATP represents a potential preventative agent against AD and could serve as an effective immunomodulator in AD patients.

Immunoreactive properties of α-casein and κ-casein: Ex vivo and in vivo studies

The aim of this study was to evaluate the ex vivo and in vivo studies immune potential of α- and κ-casein. Ex vivo, naïve mouse splenocytes were stimulated with α- or κ-casein. After 120 h of culture, the proliferation index (PI), determined by 3-(4,5 dimethylthiazol-2yl)-2,5-diphenyl tetrazolium bromide (MTT) assay and carboxyfluorescein diacetate N-succinimidyl ester (CFSE) staining, did not vary for either antigen, suggesting similar ex vivo immunogenic potential of both casein fractions. In vivo, BALB/ccmdb mice were sensitized with α- or κ-casein and then gavaged with primary antigen. Mice immunized with α-casein had higher levels of IgG (2^16.33) and IgA (2^10.22) in serum at the end of the experiment compared with mice immunized with κ-casein (2¹⁵ and 2^9.3 for IgG and IgA, respectively). The use of α-casein for mouse immunization and ex vivo lymphocyte stimulation resulted in higher concentrations of secreted cytokines (IL-4, IL-10) compared with κ-casein stimulation. This is consistent with increasing regulatory T cell (Treg) lymphocyte populations, independent of the antigen used for stimulation. In summary, the immunogenic potential of α- and κ-casein was similar. Humoral and cellular immune responses confirmed their strong, independent potential to induce B and T cells. We propose that the lymphocyte proliferation index be used as an initial screening for protein immunogenicity.

PD-1 has a unique capacity to inhibit allergen-specific human CD4+ T cell responses

T lymphocytes have a crucial role in initiating and promoting type I allergies. Their responses are tightly regulated by numerous activating and inhibitory signals provided by APCs. Here we have addressed the role of the major coinhibitory receptors PD-1, CTLA-4, BTLA and LAG-3 in allergen-specific CD4⁺ T cell responses. PBMCs of healthy individuals and 41 patients allergic to house dust mites, birch, grass or mugwort pollen were stimulated with allergenic extracts and expression of coinhibitory receptors on responding CD4⁺ T cells was assessed. Blocking antibodies to PD-1, CTLA-4, BTLA and LAG-3 were used to evaluate the role of coinhibitory pathways. Allergen-specific CD4⁺ T cells showed strong upregulation of PD-1, LAG-3 and CTLA-4 upon stimulation, whereas BTLA was downregulated. Blockade of PD-1 strongly enhanced proliferation and cytokine production (IL-10; T_H1 cytokines IFN-γ, TNF-α; T_H2 cytokines IL-5, IL-13) of allergen-specific CD4⁺ T cells derived from allergic as well as non-allergic individuals. BTLA blockade enhanced proliferation but not cytokine production in response to house dust mite extract. Blocking LAG-3 was ineffective and surprisingly, we observed reduced proliferation and cytokine production in presence of a CTLA-4 antibody. Our results point to a unique potency of PD-1 pathways to dampen allergen-specific human T cells.

Is IgE or eosinophils the key player in allergic asthma pathogenesis? Are we asking the right question?

Bronchial asthma (BA) is a chronic inflammatory disease with a marked heterogeneity in pathophysiology and etiology. The heterogeneity of BA may be related to the inducing mechanism(s) (allergic vs non-allergic), the histopathological background (eosinophilic vs non-eosinophilic), and the clinical manifestations, particularly in terms of severity and frequency of exacerbations. Asthma can be divided into at least two different endotypes based on the degree of Th2 inflammation (T2 'high' and T2 'low'). For patients with severe uncontrolled asthma, monoclonal antibodies (mAbs) against immunoglobulin E (IgE) or interleukin (IL)-5 are now available as add-on treatments. Treatment decisions for individual patients should consider the biological background in terms of the "driving mechanisms" of inflammation as this should predict the patients' likely responses to treatment. The question is not whether an anti-IgE or an anti-eosinophilic strategy is more effective, but rather what the mechanism is at the origin of the airway. While IgE is involved early in the inflammatory cascade and can be considered as a cause of allergic asthma, eosinophilia can be considered a consequence of the whole process. This article discusses the different roles of the IgE and IL-5/eosinophil pathways in the pathogenic mechanisms of airway inflammation occurring in allergic asthma, and the possible reasons to choose an anti-IgE mAb or anti-IL-5 treatment.

Pathogenic CD4+ T cells in patients with asthma

Asthma encompasses a variety of clinical phenotypes that involve distinct T cell-driven inflammatory processes. Improved understanding of human T-cell biology and the influence of innate cytokines on T-cell responses at the epithelial barrier has led to new asthma paradigms. This review captures recent knowledge on pathogenic CD4+ T cells in asthmatic patients by drawing on observations in mouse models and human disease. In patients with allergic asthma, TH2 cells promote IgE-mediated sensitization, airway hyperreactivity, and eosinophilia. Here we discuss recent discoveries in the myriad molecular pathways that govern the induction of TH2 differentiation and the critical role of GATA-3 in this process. We elaborate on how cross-talk between epithelial cells, dendritic cells, and innate lymphoid cells translates to T-cell outcomes, with an emphasis on the actions of thymic stromal lymphopoietin, IL-25, and IL-33 at the epithelial barrier. New concepts on how T-cell skewing and epitope specificity are shaped by multiple environmental cues integrated by dendritic cell "hubs" are discussed. We also describe advances in understanding the origins of atypical TH2 cells in asthmatic patients, the role of TH1 cells and other non-TH2 types in asthmatic patients, and the features of T-cell pathogenicity at the single-cell level. Progress in technologies that enable highly multiplexed profiling of markers within a single cell promise to overcome barriers to T-cell discovery in human asthmatic patients that could transform our understanding of disease. These developments, along with novel T cell-based therapies, position us to expand the assortment of molecular targets that could facilitate personalized treatments.

A pilot study comparing T-regulatory cell function among healthy children in different areas of Gansu, China

Immune system is critical to protecting human health from toxic substances. Our previously published research had found an important link between polycyclic aromatic hydrocarbons (PAHs) in ambient air and changes at the DNA level in immune cells that led to impaired function of regulatory T (Treg) cells in children living in California, USA. But molecular and cellular pathways of these changes remain unclear. The present study aims to explore whether exposure to PAHs leads to changes in Treg cells functions of children living in Gansu, China, where ambient air pollution levels are much higher than those in California, and to explore potential mechanisms of PAH-induced immunological dysfunctions. Air pollutions in Lanzhou and Lintao, Gansu Province, were measured from December 2015 to June 2016. Healthy children were recruited from both cities and enrolled in this pilot study. Demographic information was collected by questionnaires. Blood samples were collected. Peripheral blood Treg cells were analyzed for Treg cells percentage by flow cytometry. Gene expression of forkhead box transcription factor 3 (Foxp3), transforming growth factor-β (TGF-β), and interleukin 35 (IL35) were examined by reverse transcription-polymerase chain reaction (RT-PCR). The results indicated PAH concentration (as sum of 16 PAHs) in Lintao was over two times higher than that was in Lanzhou (707 vs. 326 ng/m³), whereas PM_2.5 concentration was comparable in two cities (55.3 in Lintao vs. 65.7 μg/m³ in Lanzhou). Notably, we observed lower gene expressions for Foxp3 (P < 0.05), IL35 (P < 0.05), and TGF-β, in children living in Lintao, suggesting an impairment of Treg cells function potentially associated with higher PAH exposure in Lintao. However, no significant difference was observed in Treg cells % among CD4⁺ T cells between Lanzhou and Lintao groups.

CpG oligonucleotides increase HBV-specific cytokine responses in whole blood and enhance cytokine release assay sensitivity

BACKGROUND

Chronic hepatitis B leads to liver cirrhosis and hepatocellular carcinoma. To develop a therapeutic vaccine for chronic hepatitis B patients it is necessary to assess cellular immune responses to hepatitis B virus (HBV) antigens. We investigated the potential of toll-like receptor (TLR) 9 agonists, i.e. CpG oligonucleotides, as costimulators to increase diagnostic sensitivity and specificity of our HBV- specific cytokine release assay.

METHODS

Whole blood from 80 healthy individuals (n=51 hepatitis B vaccinated, n=29 unvaccinated) was stimulated with hepatitis B surface antigen (HBsAg) or hepatitis B core antigen (HBcAg) in presence or absence of CpG oligonucleotides. IL2 and IFNγ secretion in plasma was assessed using ELISA.

RESULTS

CpG oligonucleotides specifically enhanced HBsAg-mediated IL2 (276±79pg/ml vs. 320±82pg/ml) and IFNγ (77±35pg/ml vs. 401±121pg/ml) responses in whole blood. When IFNγ release was considered as readout depicting the hepatitis B vaccination status, the according assay reached a diagnostic sensitivity of 61% without, but of 76% with additional CpG oligonucleotide stimulation at a diagnostic specificity of 90%.

CONCLUSIONS

We show that innate signals mediated via TLRs contribute to HBV-specific cellular immune responses. CpG oligonucleotides can be used to make whole blood based cytokine release assays even more powerful as screening tools in HBV immunology.

Comparing Proteolytic Fingerprints of Antigen-Presenting Cells during Allergen Processing

Endolysosomal processing has a critical influence on immunogenicity as well as immune polarization of protein antigens. In industrialized countries, allergies affect around 25% of the population. For the rational design of protein-based allergy therapeutics for immunotherapy, a good knowledge of T cell-reactive regions on allergens is required. Thus, we sought to analyze endolysosomal degradation patterns of inhalant allergens. Four major allergens from ragweed, birch, as well as house dust mites were produced as recombinant proteins. Endolysosomal proteases were purified by differential centrifugation from dendritic cells, macrophages, and B cells, and combined with allergens for proteolytic processing. Thereafter, endolysosomal proteolysis was monitored by protein gel electrophoresis and mass spectrometry. We found that the overall proteolytic activity of specific endolysosomal fractions differed substantially, whereas the degradation patterns of the four model allergens obtained with the different proteases were extremely similar. Moreover, previously identified T cell epitopes were assigned to endolysosomal peptides and indeed showed a good overlap with known T cell epitopes for all four candidate allergens. Thus, we propose that the degradome assay can be used as a predictor to determine antigenic peptides as potential T cell epitopes, which will help in the rational design of protein-based allergy vaccine candidates.

Tetramer-Guided Epitope Mapping: A Rapid Approach to Identify HLA-Restricted T-Cell Epitopes from Composite Allergens

Tetramer-guided epitope mapping (TGEM) is a technique in immunology that permits the rapid identification of allergenic epitopes through peptide screening procedures utilizing human lymphocyte antigen (HLA) class II tetramers as staining reagents for detection. The identification of allergenic epitopes is a prerequisite for the accurate characterization of allergen-specific CD4⁺ T cells without in vitro stimulation. Additionally, these MHC-II/peptide complexes that interact with T-cell receptors (TCR) of pathogenic CD4⁺ T cells are compatible with a different number of assays like Intracelullar Cytokine Staining (ICS), and Carboxyfluorescein succinimidyl ester (CFSE) making it a robust technology to study the functionality of allergen-specific CD4⁺ T cells.

T-Cell Proliferation Assay: Determination of Immunodominant T-Cell Epitopes of Food Allergens

Characterization of allergen-specific T cells is critical to understand their contribution to disease pathogenesis. The identification of immunodominant T-cell epitopes is crucial for development of T-cell-based vaccines. Peptide-specific T-cell proliferation studies are usually performed in a library of short synthetic peptides (15mer or 20mer) with 3 or 5 offset spanning the entire length of the allergen. T-cell peptide epitopes lack the primary and tertiary structure of the native protein to cross-link IgE, but retain the ability to stimulate T cells. The peptides sequences can also be obtained either by in silico approaches and in vitro binding assays. The efficacy of T-cell epitope-based peptide immunotherapy has been proven in certain allergies. The present methodology describes T-cell proliferation assays using whole blood sample from allergic subjects.

Multiplexed Nanoplasmonic Temporal Profiling of T-Cell Response under Immunomodulatory Agent Exposure

Immunomodulatory drugs—agents regulating the immune response—are commonly used for treating immune system disorders and minimizing graft versus host disease in persons receiving organ transplants. At the cellular level, immunosuppressant drugs are used to inhibit pro-inflammatory or tissue-damaging responses of cells. However, few studies have so far precisely characterized the cellular-level effect of immunomodulatory treatment. The primary challenge arises due to the rapid and transient nature of T-cell immune responses to such treatment. T-cell responses involve a highly interactive network of different types of cytokines, which makes precise monitoring of drug-modulated T-cell response difficult. Here, we present a nanoplasmonic biosensing approach to quantitatively characterize cytokine secretion behaviors of T cells with a fine time-resolution (every 10 min) that are altered by an immunosuppressive drug used in the treatment of T-cell-mediated diseases. With a microfluidic platform integrating antibody-conjugated gold nanorod (AuNR) arrays, the technique enables simultaneous multi-time-point measurements of pro-inflammatory (IL-2, IFN-γ, and TNF-α) and anti-inflammatory (IL-10) cytokines secreted by T cells. The integrated nanoplasmonic biosensors achieve precise measurements with low operating sample volume (1 μL), short assay time (∼30 min), heightened sensitivity (∼20–30 pg/mL), and negligible sensor crosstalk. Data obtained from the multicytokine secretion profiles with high practicality resulting from all of these sensing capabilities provide a comprehensive picture of the time-varying cellular functional state during pharmacologic immunosuppression. The capability to monitor cellular functional response demonstrated in this study has great potential to ultimately permit personalized immunomodulatory treatment.

Effects of Sohamhyoong-Tang on Ovalbumin-Induced Allergic Reaction in BALB/c Mice

IgE-mediated mast cell degranulation and excessive Th2 cells activation are major features of various allergic diseases. Sohamhyoong-tang has been reported to have anti-inflammatory and antibacterial effects. In this study, we investigated the inhibitory effect of Sohamhyoong-tang extract (SHHTE) on allergic symptoms and inflammatory responses in ovalbumin- (OVA-) sensitized BALB/c mice. The mice were sensitized with OVA and alum at 2-week intervals and then orally given SHHTE for 13 days followed by intradermal OVA injection. Administration of SHHTE significantly reduced edema formation and inflammatory-cell infiltration in ear tissues. Total and OVA-specific IgEs as well as proinflammatory cytokine TNF-α and Th2-associated cytokine IL-4 levels were lower in the SHHTE-treated group than in the vehicle. SHHTE treatment significantly suppressed both mRNA and protein levels of IL-4 and IL-5 in OVA-stimulated splenocytes. SHHTE decreased Th1 (IFN-γ) and Th17 (IL-17a) cytokine mRNA expression but increased Treg cytokines (IL-10 and TGF-β1). Moreover, SHHTE significantly inhibited degranulation of RBL-2H3 cell line in a dose-dependent manner. Thus, SHHTE efficiently inhibited the allergic symptoms in an OVA-sensitized mouse model and its action may correlate with the suppression of IgE production by increasing IL-10 and TGF-β1, which can limit the function of other T helper cells and prevent the release of inflammatory mediators from mast cells. These results suggest that SHHTE could be a therapeutic agent for treating various allergic diseases.

A Probiotic Preparation Alleviates Atopic Dermatitis-Like Skin Lesions in Murine Models

Atopic dermatitis (AD) is a chronic inflammatory skin disease with a complex etiology that encompasses immunologic responses. AD is frequently associated with elevated immunoglobulin (Ig) E levels, and common environmental factors contribute to its pathogenesis. Several recent studies have documented the role of specific lactic acid bacteria in the treatment and prevention of AD in humans and mice. In this study, the efficacy of Duolac ATP, a probiotic preparation, was determined in a mouse model with AD-like skin lesions. Alterations in the cytokine levels and histological staining suggested the alleviation of AD. The in vivo test showed that T helper (Th)2 cytokines, IgE, interleukin (IL)-4, and IL-5, were significantly downregulated, whereas Th1 cytokines, IL-12p40 and interferon (IFN)-γ, were upregulated in all groups of mice treated with Duolac ATP compared to that observed in the group of mice treated with 1-chloro-2,4-dinitrobenzene (DNCB) alone. Moreover, the scratch score decreased in all mice treated with Duolac ATP. Staining of the dorsal area of the mice in each group with hematoxylin and eosin and toluidine blue further confirmed the alleviation of AD in mice orally treated with Duolac ATP. These results suggest that Duolac ATP inhibits the development of AD-like skin lesions in NC/Nga mice by suppressing the Th2 cell response and increasing the Th1 cell response. Thus, Duolac ATP is beneficial and effective for the treatment of AD-like skin lesions.

Analysis of cytokine production by peanut-reactive T cells identifies residual Th2 effectors in highly allergic children who received peanut oral immunotherapy

BACKGROUND

Only limited evidence is available regarding the cytokine repertoire of effector T cells associated with peanut allergy, and how these responses relate to IgE antibodies to peanut components.

OBJECTIVE

To interrogate T cell effector cytokine populations induced by Ara h 1 and Ara h 2 among peanut allergic (PA) children in the context of IgE and to evaluate their modulation during oral immunotherapy (OIT).

METHODS

Peanut-reactive effector T cells were analysed in conjunction with specific IgE profiles in PA children using intracellular staining and multiplex assay. Cytokine-expressing T cell subpopulations were visualized using SPICE.

RESULTS

Ara h 2 dominated the antibody response to peanut as judged by prevalence and quantity among a cohort of children with IgE to peanut. High IgE (> 15 kU(A)/L) was almost exclusively associated with dual sensitization to Ara h 1 and Ara h 2 and was age independent. Among PA children, IL-4-biased responses to both major allergens were induced, regardless of whether IgE antibodies to Ara h 1 were present. Among subjects receiving OIT in whom high IgE was maintained, Th2 reactivity to peanut components persisted despite clinical desensitization and modulation of allergen-specific immune parameters including augmented specific IgG4 antibodies, Th1 skewing and enhanced IL-10. The complexity of cytokine-positive subpopulations within peanut-reactive IL-4(+) and IFN-γ(+) T cells was similar to that observed in those who received no OIT, but was modified with extended therapy. Nonetheless, high Foxp3 expression was a distinguishing feature of peanut-reactive IL-4(+) T cells irrespective of OIT, and a correlate of their ability to secrete type 2 cytokines.

CONCLUSION

Although total numbers of peanut-reactive IL-4(+) and IFN-γ(+) T cells are modulated by OIT in highly allergic children, complex T cell populations with pathogenic potential persist in the presence of recognized immune markers of successful immunotherapy.

T helper 17 cells may drive neuroprogression in major depressive disorder: Proposal of an integrative model

The exact pathophysiology of major depressive disorder (MDD) remains elusive. The monoamine theory, which hypothesizes that MDD emerges as a result of dysfunctional serotonergic, dopaminergic and noradrenergic pathways, has guided the therapy of this illness for several decades. More recently, the involvement of activated immune, oxidative and nitrosative stress pathways and of decreased levels of neurotrophic factors has provided emerging insights regarding the pathophysiology of MDD, leading to integrated theories emphasizing the complex interplay of these mechanisms that could lead to neuroprogression. In this review, we propose an integrative model suggesting that T helper 17 (Th17) cells play a pivotal role in the pathophysiology of MDD through (i) microglial activation, (ii) interactions with oxidative and nitrosative stress, (iii) increases of autoantibody production and the propensity for autoimmunity, (iv) disruption of the blood-brain barrier, and (v) dysregulation of the gut mucosa and microbiota. The clinical and research implications of this model are discussed.

Filaggrin inhibits generation of CD1a neolipid antigens by house dust mite-derived phospholipase

Atopic dermatitis is a common pruritic skin disease in which barrier dysfunction and cutaneous inflammation contribute to pathogenesis. Mechanisms underlying the associated inflammation are not fully understood, and although Langerhans cells expressing the nonclassical major histocompatibility complex (MHC) family member CD1a are known to be enriched within lesions, their role in clinical disease pathogenesis has not been studied. We observed that house dust mite (HDM) allergen generates neolipid antigens presented by CD1a to T cells in the blood and skin lesions of affected individuals. HDM-responsive CD1a-reactive T cells increased in frequency after birth in individuals with atopic dermatitis and showed rapid effector function, consistent with antigen-driven maturation. In HDM-challenged human skin, we observed phospholipase A2 (PLA2) activity in vivo. CD1a-reactive T cell activation was dependent on HDM-derived PLA2, and such cells infiltrated the skin after allergen challenge. Moreover, we observed that the skin barrier protein filaggrin, insufficiency of which is associated with atopic skin disease, inhibited PLA2 activity and decreased CD1a-reactive PLA2-generated neolipid-specific T cell activity from skin and blood. The most widely used classification schemes of hypersensitivity suggest that nonpeptide stimulants of T cells act as haptens that modify peptides or proteins; however, our results show that HDM proteins may also generate neolipid antigens that directly activate T cells. These data define PLA2 inhibition as a function of filaggrin, supporting PLA2 inhibition as a therapeutic approach.

Identification of global regulators of T-helper cell lineage specification

Background

Activation and differentiation of T-helper (Th) cells into Th1 and Th2 types is a complex process orchestrated by distinct gene activation programs engaging a number of genes. This process is crucial for a robust immune response and an imbalance might lead to disease states such as autoimmune diseases or allergy. Therefore, identification of genes involved in this process is paramount to further understand the pathogenesis of, and design interventions for, immune-mediated diseases.

Methods

We aimed at identifying protein-coding genes and long non-coding RNAs (lncRNAs) involved in early differentiation of T-helper cells by transcriptome analysis of cord blood-derived naïve precursor, primary and polarized cells.

Results

Here, we identified lineage-specific genes involved in early differentiation of Th1 and Th2 subsets by integrating transcriptional profiling data from multiple platforms. We have obtained a high confidence list of genes as well as a list of novel genes by employing more than one profiling platform. We show that the density of lineage-specific epigenetic marks is higher around lineage-specific genes than anywhere else in the genome. Based on next-generation sequencing data we identified lineage-specific lncRNAs involved in early Th1 and Th2 differentiation and predicted their expected functions through Gene Ontology analysis. We show that there is a positive trend in the expression of the closest lineage-specific lncRNA and gene pairs. We also found out that there is an enrichment of disease SNPs around a number of lncRNAs identified, suggesting that these lncRNAs might play a role in the etiology of autoimmune diseases.

Conclusion

The results presented here show the involvement of several new actors in the early differentiation of T-helper cells and will be a valuable resource for better understanding of autoimmune processes.

Electronic supplementary material

The online version of this article (doi:10.1186/s13073-015-0237-0) contains supplementary material, which is available to authorized users.

Multicolor flow-cytometric analysis of milk allergen-specific T-helper type 2 cells revealed coexpression of interleukin-4 with Foxp3

BACKGROUND

Allergen-specific T-helper type 2 (TH2) cells play an important role in the development of allergic inflammation; however, investigations of the properties of allergen-specific T cells have been challenging in humans. Despite clear evidence that forkhead box p3 (Foxp3) is expressed in conventional effector T cells, its function has remained unknown.

OBJECTIVE

To characterize allergen-specific TH2 cells in milk allergy, with particular focus on the expression of Foxp3.

METHODS

Twenty-one children with milk allergy and 11 children without milk allergy were studied. Peripheral blood mononuclear cells from subjects were stimulated with milk allergen for 6 hours and analyzed using multicolor flow cytometry to identify CD154(+) allergen-specific T-helper cells. Simultaneously, the expression of intracellular cytokines and Foxp3 was analyzed.

RESULTS

The milk allergy group had significantly larger numbers of milk allergen-specific interleukin (IL)-4- and IL-5-producing CD4(+) T cells than the control group. Subjects in the milk allergy group had significantly more CD154(+)CD4(+) IL-10-producing cells and CD154(+)Foxp3(+)CD4(+) cells than those in the control group. In addition, the number of milk allergen-specific CD154(+)Foxp3(+)CD4(+) cells strongly correlated with that of CD154(+)IL4(+)CD4(+) cells. Bcl-2 expression in CD154(+)IL-4(+)Foxp3(+) T-helper cells was significantly lower compared with that in total CD4 cells.

CONCLUSION

Increased numbers of IL-4-producing allergen-specific T-helper cells were found in patients with milk allergy. In addition, Foxp3 was coexpressed with IL-4 in allergen-specific TH2 cells from patients. This coexpression was associated with lower Bcl-2 levels and could contribute to the phenotype and function of TH2 cells.

Characterization of human memory CD4(+) T-cell responses to the dog allergen Can f 4

BACKGROUND

The recently identified dog lipocalin allergen Can f 4 is an important respiratory allergen.

OBJECTIVE

We sought to comprehensively characterize the memory CD4(+) T-cell responses of allergic and nonallergic subjects to Can f 4.

METHODS

Can f 4-specific CD4(+)CD45RO(+) T-cell lines (TCLs) from allergic and healthy subjects were established and characterized by their functional and phenotypic properties. The epitope specificity of the TCLs was tested with 48 overlapping 16-mer peptides spanning the sequence of Can f 4. HLA restriction of the specific TCLs and the binding capacity of the epitope-containing peptides to common HLA class II molecules were studied.

RESULTS

Can f 4-specific memory CD4(+) TCLs were obtained at an 8-fold higher frequency from allergic than from nonallergic subjects. Functionally, the TCLs of allergic subjects exhibited a higher T-cell receptor avidity and expression of CD25 and predominantly produced IL-4 and IL-5. The TCLs of nonallergic subjects mostly secreted IFN-γ and IL-10, with high CXCR3 expression. Several distinct T-cell epitope regions along the allergen were identified. Importantly, the peptides from the region between amino acids 43 and 67 showed promiscuous HLA-binding capacity and induced memory CD4(+) T-cell responses in 90% of the allergic donors.

CONCLUSION

Productive TH2-deviated memory T-cell responses to Can f 4 are observed in allergic but not nonallergic subjects. A 19-mer peptide sequence covering the core of the immunodominant region of the allergen is a potential target for the development of peptide-based allergen immunotherapy.

Jug r 2-reactive CD4(+) T cells have a dominant immune role in walnut allergy

Background

Allergic reactions to walnut can be life threatening. While IgE epitopes of walnut have been studied, CD4⁺ T-cell specific epitopes for walnut remain uncharacterized. Particularly, the relationship of both phenotype and frequency of walnut specific T-cells to the disease have not been examined.

Objectives

We sought to provide a thorough phenotypic analysis for walnut reactive T-cells in allergic and non-allergic subjects. Particularly, the relationship of phenotypes and frequencies of walnut specific T-cells with the disease.

Methods

CD154 up-regulation assay was used to examine CD4⁺ T-cell reactivity towards walnut allergens.Jug r 1, Jug r 2 and Jug r 3. Tetramer-Guided epitope mapping approach was utilized to identify HLA-restricted CD4⁺ T-cells epitopes in Jug r 2. Direct ex vivo staining with peptide-major histocompatibility complex class II (pMHC-II) tetramers enabled the comparison of frequency and phenotype of Jug r 2-specific CD4⁺ T-cells between allergic and non-allergic subjects. Jug r 2-specific T-cell-clones were also generated and mRNA transcription factor levels were assessed by RT qPCR. Intracellular cytokine staining (ICS) assays were performed for further phenotypical analyses.

Results

Jug r 2 was identified as the major allergen that elicited CD4⁺ T-cell responses. Multiple Jug r 2 T-cell epitopes were identified. The majority of these T-cells in allergic subjects have a CCR4⁺ T_CM (central memory) phenotype. A subset of these T-cells express CCR4⁺CCR6⁺ irrespectively of the asthmatic status of the allergic subjects. ICS confirmed these T_H2, T_H2/T_H17 and T_H17-like heterogenic profiles. Jug r 2-specific T-cell-clones from allergic subjects mainly expressed GATA3; nonetheless, a portion of T-cell clones expressed either GATA3 and RORC, or RORC, confirming the presence of T_H2, T_H2/T_H17 and T_H17 cells.

Conclusions

Jug r 2 specific responses dominate walnut T-cell responses in subjects with walnut allergy. Jug r 2 central memory CD4⁺ cells and terminal effector T-cells were detected in peripheral blood with the central memory phenotype as the most prevalent phenotype. In addition to conventional T_H2-cells, T_H2/T_H17 and T_H17 cells were also detected in non-asthmatic and asthmatic subjects with walnut allergy. Understanding this T-cell heterogeneity may render better understanding of the disease manifestation.

Improvement of atopic dermatitis-like skin lesions by IL-4 inhibition of P14 protein isolated from Lactobacillus casei in NC/Nga mice

Atopic dermatitis (AD) is a chronic inflammatory skin disease, with a complex etiology encompassing immunologic responses. AD is frequently associated with elevated serum immunoglobulin (Ig) E levels and is exacerbated by a variety of environmental factors, which contribute to its pathogenesis. However, the etiology of AD remains unknown. Recently, reports have documented the role of lactic acid bacteria (LAB) in the treatment and prevention of AD in humans and mice. The LAB, Lactobacillus casei (LC), is frequently used in the treatment of AD. To identify the active component of LC, we screened fractions obtained from the ion exchange chromatography of LC extracts. Using this approach, we identified the candidate protein, P14. We examined whether the P14 protein has anti-atopic properties, using both in vitro and in vivo models. Our results showed that the P14 protein selectively downregulated serum IgE and interleukin-4 cytokine levels, as well as the AD index and scratching score in AD-like NC/Nga mice. In addition, histological examination was also effective in mice. These results suggest that the P14 protein has potential therapeutic effects and that it may also serve as an effective immunomodulatory agent for treating patients with AD.

The effectiveness of acupuncture compared to loratadine in patients allergic to house dust mites

Background. The aim of this work was to evaluate the clinical effectiveness of acupuncture and its impact on the immune system in comparison to loratadine in the treatment of persistent allergic rhinitis caused by house dust mites. Methods. In this study, 24 patients suffering from persistent allergic rhinitis induced by house dust mites were treated either with acupuncture (n = 15) or with loratadine (n = 9). The evaluation of the data was based on the subjective and the objective rhinoconjunctivitis symptom scores, specific and total IgE, and interleukins (IL-4, IL-10, and IFN- γ ) as markers for the activity of Th1 or Th2 cells. Results. The treatments with acupuncture as well as with loratadine were considered effective in the patients' subjective assessment, whereby the effect of the acupuncture tended to be assessed as more persistent after the end of treatment. A change in the specific or the total IgE was not detectable in either group. The interleukin profile showed the tendency of an increasing IL-10 value in the acupuncture group. The results of the study show that the effectiveness of acupuncture is comparable to that of loratadine. Conclusion. Acupuncture is a clinically effective form of therapy in the treatment of patients suffering from persistent allergic rhinitis. The results indicate the probability of an immunomodulatory effect.

Acupuncture in allergic rhinitis: A Mini-Review

Acupuncture is a therapy method known for millennia with apparently polygenetic roots. It is traditionally practiced in East Asian countries. During the recent fifty years, it has found wide applications in Europe as well. Today acupuncture is one of the most important parts of modern complementary medicine. Questions concerning the mechanism of action and efficacy of acupuncture, among others in the treatment of allergic rhinitis, still lead to many scientific discussions. This review summarizes the modern understanding of possible mechanisms of acupuncture as well as it presents the current state of clinical studies relating to the efficacy of acupuncture in the treatment of allergic rhinitis. Further investigations are necessary to confirm acupuncture as an effective therapy of allergic rhinitis.

MicroRNAs act complementarily to regulate disease-related mRNA modules in human diseases

MicroRNAs (miRNAs) play a key role in regulating mRNA expression, and individual miRNAs have been proposed as diagnostic and therapeutic candidates. The identification of such candidates is complicated by the involvement of multiple miRNAs and mRNAs as well as unknown disease topology of the miRNAs. Here, we investigated if disease-associated miRNAs regulate modules of disease-associated mRNAs, if those miRNAs act complementarily or synergistically, and if single or combinations of miRNAs can be targeted to alter module functions. We first analyzed publicly available miRNA and mRNA expression data for five different diseases. Integrated target prediction and network-based analysis showed that the miRNAs regulated modules of disease-relevant genes. Most of the miRNAs acted complementarily to regulate multiple mRNAs. To functionally test these findings, we repeated the analysis using our own miRNA and mRNA expression data from CD4+ T cells from patients with seasonal allergic rhinitis. This is a good model of complex diseases because of its well-defined phenotype and pathogenesis. Combined computational and functional studies confirmed that miRNAs mainly acted complementarily and that a combination of two complementary miRNAs, miR-223 and miR-139-3p, could be targeted to alter disease-relevant module functions, namely, the release of type 2 helper T-cell (Th2) cytokines. Taken together, our findings indicate that miRNAs act complementarily to regulate modules of disease-related mRNAs and can be targeted to alter disease-relevant functions.