Effects of extremely preterm birth on cytokine and chemokine responses induced by T-cell activation during infancy.

Objectives: Extremely preterm (EPT; gestational week < 28 + 0, < 1000 g) neonates are vulnerable to infections and necrotising enterocolitis, important contributors to mortality and morbidity. However, knowledge regarding their immune maturation remains limited. We here investigated the longitudinal development of functional T-cell capacity in EPT infants. Methods: Peripheral blood mononuclear cells were isolated at 14th and 28th day (D) and at gestational week 36 + 0 (Gw36) from EPT infants, participated in a randomised, double-blind, placebo-controlled study of Lactobacillus reuteri DSM 17938 probiotic supplementation. Blood collected from 25 full-term (FT) infants at D14 was used as control. The secretion of immune mediators was determined through comprehensive Luminex panels after stimulation with human T-cell activator CD3/CD28 beads. Results: The levels of many mediators were low in EPT infants at D14, whereas the secretion of several chemokines was higher in EPT than in FT infants. Furthermore, Th2:Th1 cytokine ratios were higher in EPT than in FT infants. Progressively elevated secretion of, for example, IFN-γ, TNF and IL-17A in EPT infants was observed from D14 to D28 and then at Gw36. Elevated levels were observed for many proinflammatory mediators at D28. Probiotic supplementation or perinatal factors (e.g. clinical chorioamnionitis, preeclampsia and delivery mode) did not influence the cytokine and chemokine responses. Conclusions: Immune mediators induced by T-cell activation in EPT infants were mainly reduced at D14 and Th2 skewed compared to those in FT infants, but mostly recovered at Gw36, indicating immune maturation. Increased proinflammatory responses at D28 may be related to the heightened risk of severe immune-associated complications seen in EPT infants.

Immune-related microRNAs in breast milk and their relation to regulatory T cells in breastfed children.

BACKGROUND: The immunomodulatory capacity of breast milk may partially be mediated by microRNAs (miRNA), small RNA molecules that regulate gene expression on a post-transcriptional level and are hypothesized to be involved in modulation of immunological pathways. Here, we evaluate the expression of immune-related miRNAs in breast milk after pre- and postnatal supplementation with Limosilactobacillus reuteri and omega-3 (ω-3) polyunsaturated fatty acids (PUFAs), and the association to infant regulatory T cell (Treg) frequencies. METHODS: One-hundred and twenty women included in a double-blind, randomized, placebo-controlled allergy intervention trial received L. reuteri and/or ω-3 PUFAs daily from gestational week 20. Using Taqman qPCR, 24 miRNAs were analyzed from breast milk obtained at birth (colostrum) and after 3 months (mature milk) of lactation. The proportion of activated and resting Treg cells were analyzed in infant blood using flow cytometry at 6, 12, and 24 months. RESULTS: Relative expression changed significantly over the lactation period for most of the miRNAs; however, the expression was not significantly influenced by any of the supplements. Colostrum miR-181a-3p correlated with resting Treg cell frequencies at 6 months. Colostrum miR-148a-3p and let-7d-3p correlated with the frequencies of activated Treg cells at 24 months, as did mature milk miR-181a-3p and miR-181c-3p. CONCLUSION: Maternal supplementation with L. reuteri and ω-3 PUFAs did not significantly affect the relative miRNA expression in breast milk. Interestingly, some of the miRNAs correlate with Treg subpopulations in the breastfed children, supporting the hypothesis that breast milk miRNAs could be important in infant immune regulation. TRIAL REGISTRATION: ClinicalTrials.gov-ID: NCT01542970.

Intralymphatic immunotherapy with birch and grass pollen extracts. A randomized double-blind placebo-controlled clinical trial.

INTRODUCTION: There is a need to evaluate the safety and efficacy of intralymphatic immunotherapy (ILIT) for inducing tolerance in patients with allergic rhinitis. METHODS: Thirty-seven patients with seasonal allergic symptoms to birch and grass pollen and skin prick test >3 mm and/or IgE to birch and timothy >0.35 kU/L were randomized to either ILIT, with three doses of 0.1 mL of birch pollen and 5-grass pollen allergen extracts on aluminium hydroxide (10,000 SQ-U/ml; ALK-Abelló) or placebo using ultrasound-guided intralymphatic injections at monthly intervals. Daily combined symptom medical score and rhinoconjunctivitis total symptom score were recorded during the peak pollen seasons the year before and after treatment. Rhinoconjunctivitis total symptom score, medication score and rhinoconjunctivitis quality of life questionnaire were recorded annually starting 2 years after treatment. Circulating proportions of T helper cell subsets and allergen-induced cytokine and chemokine production were analysed using flow cytometry and ELISA. RESULTS: There were no differences between the groups related to daily combined symptom medical score the year before and after treatment. Two years after ILIT (after unblinding), the actively treated group reported significantly fewer symptoms, lower medication use and improved quality of life than did the placebo group. After the pollen seasons the year after ILIT, T regulatory cell frequencies and grass-induced IFN-γ levels increased only in the actively treated group. CONCLUSION: In this randomized controlled trial, ILIT with birch and grass pollen extract was safe and accompanied by immunological changes. Further studies are required to confirm or refute the efficacy of the treatment.

T cell epitopes of Per a 10 modulate local-systemic immune responses and airway inflammation by augmenting Th1 and T regulatory cell functions in murine model.

Peptide immunotherapy (PIT) represents a safe and efficacious therapeutic modality for allergic diseases. Present study evaluates immunotherapeutic potential of T cell peptides of major cockroach allergen, Per a 10 in murine model of airway allergy. Treatment with peptides T-P8 and T-P10 demonstrated maximal resolution of pathophysiological features such as reduced recruitment of inflammatory cells to airways, lowered specific IgE, induction of IgG2a antibodies in serum, immune deviation towards Th1 cytokine milieu, suppression of Th2 cytokines in BALF and splenocyte culture supernatant and resolution of lung inflammation. A significant increase in CD4+Foxp3+ cells in spleen indicate towards induction of T regulatory cell mediated peripheral tolerance characterized by shift in cytokine milieu from Th2 to T regulatory cytokines. PIT modulates regulation of immune responses at both local and systemic levels, contributes towards holistic improvement in allergic features in mice and thus demonstrate potential for safe, specific and efficacious treatment for cockroach allergy.

Immunogenic peptides: B & T Cell Epitopes of Per a 10 Allergen of Periplaneta americana.

Mapping of B and T cell epitopes of an allergen can be utilised in the development of alternative therapeutic modalities and diagnostics. The present study was aimed to identify B and T cell epitopes of Per a 10, a major cockroach allergen, by computational tools and subsequent validation by in vitro experiments. Per a 10 three-dimensional structure was homology modelled using structure of anionic trypsin from pacific chum salmon as a template. Seven B cell epitopes (B-P1 to B-P7) were predicted by sequence and structure based methods. Three T cell epitopes (T-P8 to T-P10) were predicted by binding score and inhibitory concentration dependent prediction tools. Predicted epitopes were synthesized and biological activity was assessed by ELISA, ELISA inhibition and PBMC proliferation assays. B cell peptides B-P5, B-P6 and B-P7 showed significantly high IgE binding with pooled and individual cockroach hypersensitive patients' sera while the T cell peptides did not show IgE binding. ELISA inhibition was performed to determine the potency of the predicted peptides. Fifty nanogram of peptide B-P7 was required for 50% IgE binding inhibition of surface bound Per a 10 whereas seventy five nanogram and ninety nanogram of B-P5 and B-P6 were required for the same respectively. Upon stimulation with T-P8 and T-P10 peptides, PBMCs from cockroach allergic patients' (n = 15) showed significant lymphocyte proliferation and induced IL-4 and IL-5 cytokine release in the culture supernatant demonstrating Th2 dominant cell mediated response of predicted T cell peptides. In conclusion, Per a 10 3-D structure obtained by homology modelling was used to identify B and T cell epitopes, followed by in vitro validation. The identified peptides can be potentially used in designing diagnostics and therapies for cockroach allergy.

Intranasal administration of a combination of choline chloride, vitamin C, and selenium attenuates the allergic effect in a mouse model of airway disease.

Respiratory allergic disease is an inflammatory condition accompanied by oxidative stress. Supplementation of an anti-inflammatory agent with antioxidants may have a therapeutic effect. In this study, the effects of choline chloride in combination with antioxidants were evaluated via the intranasal route in a mouse model of allergic airway disease. Balb/c mice were sensitized on days 0, 7, and 14 and challenged on days 25-30 with cockroach extract (CE) and with a booster challenge on day 38. They were treated with choline chloride (ChCl; 1mg/kg), vitamin C (Vit C; 308.33 mg/kg), and selenium (Se; 1mg/kg) alone or in combination via the intranasal route on days 31, 33, 35, 37, and 39. The mice were sacrificed on day 40 to collect blood, bronchoalveolar lavage fluid, lungs, and spleen. Mice immunized with CE showed a significant increase in airway hyperresponsiveness (AHR), lung inflammation, Th2 cytokines, and the oxidative stress markers intracellular reactive oxygen species and 8-isoprostanes compared to the phosphate-buffered saline control group. A significant decrease was observed in these parameters with all the treatments (p<0.01). The highest decrease was noticed in the ChCl+Vit C+Se-treated group, with AHR decreased to the normal level. This group also showed the highest decrease in airway inflammation (p<0.001), IL-4 and IL-5 (p<0.001), IgE and IgG1 (p<0.001), NF-κB (p<0.001), and 8-isoprostane levels (p<0.001). Glutathione peroxidase activity, which was decreased significantly in CE-immunized mice, was restored to normal levels in this group (p<0.001). IL-10 level was decreased in CE-immunized mice and was restored to normal by combination treatment. The combination treatment induced FOXP3(+) cells in splenocyte culture, responsible for the upregulation of IL-10. In conclusion, the combination of choline chloride, vitamin C, and selenium via the intranasal route reduces AHR, inflammation, and oxidative stress, probably by causing IL-10 production by FOXP3(+) cells, and possesses therapeutic potential against allergic airway disease.

Characterization of recombinant per a 10 from Periplaneta americana.

Cockroach allergen is a major risk factor for IgE-mediated allergic response and asthma in sensitized individuals. Serine proteases have been identified from various sources and characterized as major allergens. The present study was aimed to express and characterize recombinant allergen Per a 10 (rPer a 10) from Periplaneta americana. rPer a 10 was expressed in Escherichia coli and purified in soluble form, yielding 0.75 mg/liter of culture. Homology of the Per a 10 protein sequence exhibited 27 to 38% similarity to the mite serine protease and 41 to 52% similarity to other insect trypsins. The purified rPer a 10 protein resolved at 28 kDa on SDS-PAGE and was recognized by cockroach-hypersensitive patients' sera by immunoblotting and enzyme-linked immunosorbent assay (ELISA). In competitive ELISA, rPer a 10 required 96 ng of purified protein for 50% inhibition of IgE binding, whereas 34 ng of native protein (nPer a 10) was required for the same inhibition. rPer a 10 and nPer a 10 induced basophil histamine release in the range of 47 to 64% and 60 to 85%, respectively, when sensitized with cockroach-hypersensitive patients' sera. In conclusion, Per a 10 was subcloned, and the protein was purified to homogeneity. rPer a 10 showed reduced IgE binding and histamine release and showed no proteolytic activity. These data suggest that rPer a 10 has potential for immunotherapy.