Allergen-specific responses of CD19(high) and CD19(low) B Cells in Non-IgE-mediated food allergy of late eczematous reactions in atopic dermatitis: presence of IL-17- and IL-32-producing regulatory B cells (Br17 & Br32)

Preconceptional allergen immunization can induce offspring IL-17 secreting B cells (B17): do they share similarities with regulatory B10 cells?

BACKGROUND

IL-17-producing B cells can be identified in both mice and human and were named B17 cells. The role of B17 cells still needs to be elucidated and its inflammatory or regulatory functions remain controversial.

OBJECTIVE

We evaluate the effect of maternal immunization with OVA on offspring B cells that produces IL-17 and can show a regulatory potential by IL-10 production.

METHODS

C57BL/6 WT, IL-10^-/- or CD28^-/- female mice were immunized or not with OVA in Alum, and immunized females were boosted after 10 and 20 days. Immunized and non-immunized females were mated, and pups from both groups were evaluated at 3 or 20 days old (d.o.). Some offspring from the aforementioned two groups were immunized with OVA at 3 d.o., boosted after 10 days and evaluated at 20 d.o.

RESULTS

Maternal immunization with OVA induced offspring B cells to produce IL-17 at higher intensity compared to the control group of offspring at 3 d.o. This effect was maintained until 20 d.o. and even after neonatal immunization with OVA. The co-production of IL-10 on offspring IL-17+B cells is up-regulated in response to maternal immunization with OVA. Maternal immunization with OVA on IL-10^-/- mice reveals reduced percentage and mean of fluorescence intensity of IL-17 on B cells of offspring.

CONCLUSION

Preconception OVA immunization can induce offspring B cells that produce IL-17 at higher intensity and co-produce mainly IL-10. This could be the reason why B17 cells had been described in the literature with controversial roles upon their regulatory function.

Interleukin-32 induced thymic stromal lymphopoietin plays a critical role in the inflammatory response in human corneal epithelium

Interleukin (IL)-32, a novel cytokine, participates in a variety of inflammatory disorders. Thymic stromal lymphopoietin (TSLP) plays important roles in mucosal epithelial cells, especially in allergy-induced inflammation, through the TSLP-TSLPR (thymic stromal lymphopoietin receptor) signalling pathway. However, the association of IL-32 with TSLP on the ocular surface remains unclear. The present work aimed to assess the functional association of IL-32 with TSLP in the control of pro-inflammatory cytokine levels in the corneal epithelium. Human corneal tissue specimens and human corneal epithelial cells (HCECs) were administered different concentrations of IL-32 in the presence or absence of various inhibitors to assess TSLP levels and localization, as well as the molecular pathways that control pro-inflammatory cytokine production. TSLP mRNA levels were determined by real time RT- PCR, while protein levels were quantitated by ELISA and immunohistochemical staining. TSLP protein expression was examined in donor corneal epithelium samples. IL-32 significantly upregulated TSLP and pro-inflammatory cytokines (TNFα and IL-6) in HCECs at the gene and protein levels. The production of pro-inflammatory molecules by IL-32 was increased by recombinant TSLP. Interestingly, both NF-κB (quinazoline) and caspase-1 (VX-765) inhibitors suppressed the IL-32-related upregulation of pro-inflammatory cytokines (TNFα and IL-6). These findings demonstrate that IL-32 and IL-32-induced-TSLP are critical cytokines that participate in inflammatory responses through the caspase-1 and NF-κB signalling pathways in the corneal epithelium, suggesting new molecular targets for inflammatory diseases of the ocular surface. The effects of IL-32 on cell proliferation and apoptosis were investigated by MTT assays and RT-PCR,respectively. The results demonstrated that IL-32 inhibits cells apoptosis in HCECs.

Potential Role for Regulatory B Cells as a Major Source of Interleukin-10 in Spleen from Plasmodium chabaudi-Infected Mice

Interleukin-10 (IL-10)-producing regulatory B (Breg) cells were found to be induced in a variety of infectious diseases. However, its importance in the regulation of immune response to malaria is still unclear. Here, we investigated the dynamics, phenotype, and function of Breg cells using Plasmodium chabaudi chabaudi AS-infected C57BL/6 and BALB/c mice. BALB/c mice were more susceptible to infection and had a stronger IL-10 response in spleen than C57BL/6 mice. Analysis of the surface markers of IL-10-producing cells with flow cytometry showed that CD19⁺ B cells were one of the primary IL-10-producing populations in P. c. chabaudi AS-infected C57BL/6 and BALB/c mice, especially in the latter one. The Breg cells had a heterogeneous phenotype which shifted during infection. The well-established Breg subset, CD19⁺ CD5⁺ CD1d^hi cells, accounted for less than 20% of IL-10-producing B cells in both strains during the course of infection. Most Breg cells were IgG⁺ and CD138^- from day 0 to day 8 postinfection. Adoptive transfer of Breg cells to C57BL/6 mice infected with P. c. chabaudi AS led to a transient increase of parasitemia without an impact on survival rate. Our finding reveals that B cells play an active and important regulatory role in addition to mediating humoral immunity in immune response against malaria, which should be paid more attention in developing therapeutic or vaccine strategies against malaria involving stimulation of B cells.

Analysis of Peripheral B Cell Subsets in Patients With Allergic Rhinitis

Purpose

Recent evidence suggests that B cells can both promote and inhibit the development and progression of allergic disease. However, the characteristics of B cell subsets in patients with allergic rhinitis (AR) have not been well documented. This study aimed to analyze the characteristics of B cell subsets in the peripheral blood of AR patients.

Methods

Forty-seven AR patients and 54 healthy controls were enrolled in this study, and the B cell subsets in peripheral blood of all subjects were analyzed by flow cytometry. Moreover, the serum total immunoglobulin E (IgE) and IgE concentrations secreted into the cultured peripheral blood mononuclear cells (PBMCs) were measured by using enzyme-linked immunosorbent assay.

Results

We found the peripheral blood of AR patients contained higher percentages of memory B cells, plasma cells, and CD19⁺CD24^hiCD27⁺ regulatory B cells (Bregs) than those of age-matched healthy controls (P<0.05), while the percentages of naïve B cells and CD19⁺CD24^hiCD38^hi Bregs were significantly lower in AR patients than in healthy individuals (P<0.05). In addition, the serum total IgE and IgE concentrations secreted into the cultured PBMCs were elevated in AR patients than in the healthy controls (P<0.05).

Conclusions

Our findings indicate that AR patients were characterized by increase in terminally differentiated memory B cells or plasma cells and decreases in CD19⁺CD24^hiCD38^hi Breg cells in the peripheral blood.

The Expansion of CD25 high IL-10 high FoxP3 high B Regulatory Cells Is in Association with SLE Disease Activity

B regulatory cells (Bregs) belong to a subgroup of activated B cells tasked with maintaining self-tolerance and preventing autoimmunity. While sharing similar regulatory mechanisms such as IL-10 dependency, they also defer in exhibiting their suppressive effects by expressing Fas-Ligand, TGF-beta, and PDL-1. In this study we show, for the first time, the expansion of CD25(high)FoxP3(high) Bregs in systemic lupus erythematosus (SLE) patients compared to healthy individuals (18.5 ± 3.052% versus 11.0 ± 1.654%, p < 0.001, resp.). This expansion was also shown to correlate with SLE disease activity (r = 0.75). In addition, CD25(high)FoxP3(high) Bregs were also IL-10(high) expressing and further expanded when stimulated with semaphorin 3A. In sum we show that CD25(high)FoxP3(high) are an additional subtype of Bregs, involved in regulating SLE disease activity. Being IL-10 expressing, we may assume that they are one of the sources of increased serum IL-10 in SLE patients. Further studies are required in order to assess the relation between high serum IL-10 and CD25(high)FoxP3(high) Breg cells.

Clinical spectrum of food allergies: a comprehensive review

Food allergy is defined as an adverse immune response towards food proteins or as a form of a food intolerance associated with a hypersensitive immune response. It should also be reproducible by a double-blind placebo-controlled food challenge. Many reported that food reactions are not allergic but are intolerances. Food allergy often presents to clinicians as a symptom complex. This review focuses on the clinical spectrum and manifestations of various forms of food allergies. According to clinical presentations and allergy testing, there are three types of food allergy: IgE mediated, mixed (IgE/Non-IgE), and non-IgE mediated (cellular, delayed type hypersensitivity). Recent advances in food allergy in early childhood have highlighted increasing recognition of a spectrum of delayed-onset non-IgE-mediated manifestation of food allergy. Common presentations of food allergy in infancy including atopic eczema, infantile colic, and gastroesophageal reflux. These clinical observations are frequently associated with food hypersensitivity and respond to dietary elimination. Non-IgE-mediated food allergy includes a wide range of diseases, from atopic dermatitis to food protein-induced enterocolitis and from eosinophilic esophagitis to celiac disease. The most common food allergies in children include milk, egg, soy, wheat, peanut, treenut, fish, and shellfish. Milk and egg allergies are usually outgrown, but peanut and treenut allergy tends to persist. The prevalence of food allergy in infancy is increasing and may affect up to 15-20 % of infants. The alarming rate of increase calls for a public health approach in the prevention and treatment of food allergy in children.

Monitoring immune modulation by nutrition in the general population: identifying and substantiating effects on human health

Optimal functioning of the immune system is crucial to human health, and nutrition is one of the major exogenous factors modulating different aspects of immune function. Currently, no single marker is available to predict the effect of a dietary intervention on different aspects of immune function. To provide further guidance on the assessment and interpretation of the modulation of immune functions due to nutrition in the general population, International Life Sciences Institute Europe commissioned a group of experts from academia, government and the food industry to prepare a guidance document. A draft of this paper was refined at a workshop involving additional experts. First, the expert group defined criteria to evaluate the usefulness of immune function markers. Over seventy-five markers were scored within the context of three distinct immune system functions: defence against pathogens; avoidance or mitigation of allergy; control of low-grade (metabolic) inflammation. The most useful markers were subsequently classified depending on whether they by themselves signify clinical relevance and/or involvement of immune function. Next, five theoretical scenarios were drafted describing potential changes in the values of markers compared with a relevant reference range. Finally, all elements were combined, providing a framework to aid the design and interpretation of studies assessing the effects of nutrition on immune function. This stepwise approach offers a clear rationale for selecting markers for future trials and provides a framework for the interpretation of outcomes. A similar stepwise approach may also be useful to rationalise the selection and interpretation of markers for other physiological processes critical to the maintenance of health and well-being.