INTRODUCTION: Probiotic administration seems to be a rational approach to promote maturation of the neonatal immune system. Mutual interaction of the microbiota with the host immune system is critical for the setting of appropriate immune responses including a tolerogenic one and thevmaintenance of homeostasis. On the other hand, our knowledge on the modes of actions of probiotics is still scarce. METHODS: In our study, probiotic strain Escherichia coli O83:K24:H31 (EcO83) was administered to neonates of allergic mothers (AMs; neonates with increased risk for allergy development) within 48 h after the delivery, and the impact of this early postnatal supplementation on allergy incidence and selected immune markers has been analyzed 10 years after the primary EcO83 administration. RESULTS: We have observed decreased allergy incidence in 10-year-old children supplemented with EcO83 (13 of 52 children were allergic) in comparison with non-supplemented children of AMs (16 of 42 children were allergic). The early postnatal EcO83 supplementation appeared to limit the allergy in the high-risk group (children of AMs) compared to that in the low-risk group (children of healthy mothers). Dendritic cells (DCs) in the peripheral blood of EcO83-supplemented children do not differ significantly in cell surface presence of CD83. The immunomodulatory capacity of EcO83 on DCs was tested in vitro as well. Both directly isolated myeloid and in vitro monocyte-derived DCs from cord blood increased CD83 expression together with interleukin (IL)-10 secretion after EcO83 stimulation. The effect of early postnatal EcO83 supplementation on the microbiota composition of 10-year-old children was characterized by next-generation sequencing, and we have not observed significant changes in the microbiota composition of EcO83-supplemented and non-supplemented children at the age of 10 years. CONCLUSIONS: Early postnatal EcO83 supplementation appears to lower allergy incidence in children of AMs. It seems that the beneficial effect of EcO83 is mediated via modulation of DC functional capacities without impacting the microbiota composition. Larger-scale studies will be necessary to confirm these preliminary findings.

• Keywords
• CD83, Escherichia coli O83:K24:H31, IL-10, allergy, cord blood, dendritic cell, flow cytometry, probiotic,
• MeSH
• Hypersensitivity * epidemiology   prevention & control   MeSH
• Dendritic Cells MeSH
• Child MeSH
• Escherichia coli physiology   MeSH
• Incidence MeSH
• Humans MeSH
• Microbiota * MeSH
• Monocytes MeSH
• Infant, Newborn MeSH
• Probiotics * MeSH
• Check Tag
• Child MeSH
• Humans MeSH
• Infant, Newborn MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

Understanding the early events involved in the induction of immune tolerance to harmless environmental antigens and microbiota compounds could reveal potential targets for allergic disease therapy or prevention. Regulatory T cells (Treg), particularly induced Treg (iTreg), are crucial for the induction and maintenance of tolerance against environmental antigens including allergens. A decrease in the number and/or function of Treg or iTreg could represent an early predictor of allergy development. We analyzed proportional and functional properties of Treg in the cord blood of children of allergic mothers (neonates at high risk of allergy development) and healthy mothers (neonates with relatively low risk of allergy development). We observed a higher number of induced Treg in the cord blood of females compared to males, suggesting an impaired capacity of male immunity to set up tolerance to allergens, which could contribute to the higher incidence of allergy observed in male infants. The decreased proportion of iTreg in cord blood compared with maternal peripheral blood documents the general immaturity of the neonatal immune system. We observed a positive correlation in the demethylation of the Treg-specific demethylated region (TSDR) and the proportion of Treg in cord blood. Our data suggest that immaturity of the neonatal immune system is more severe in males, predisposing them to increased risk of allergy development.

• Keywords
• Helios, TSDR, allergy, cord blood, epigenetics, flow cytometry, induced Treg, natural Treg, regulatory T cells,
• Publication type
• Journal Article MeSH

Allergic diseases represent some of the most common immunological disorders with high clinical and economic impact. Despite intensive research, there are still few universally accepted and reliable biomarkers capable of predicting their development at an early age. There is therefore a pressing need for identification of potential predictive factors and validation of their prognostic value by correlating them with allergy development. Dysbalance of the branches of immune response, most often excessive Th2 polarization, is the principal cause of allergic diseases. Regulatory T cells (Treg) are a crucial population for the timely establishment of physiological immune polarization and induction and maintenance of tolerance against environmental antigens. This makes them a potentially promising candidate for an early marker predicting allergy development. In our study, we analysed samples of cord blood of children of allergic mothers and children of healthy mothers by flow cytometry and retrospectively correlated the data with clinical allergy status of the children at the age of 6 to 10 years. Studied parameters included cord blood Treg population proportions and functional properties - intracellular presence of IL-10 and TGF-b, MFI of FoxP3. We observed higher percentage of Tregs in cord blood of children who did not develop allergy compared with allergic children. Further, we found higher numbers of IL-10+ Tregs in cord blood of healthy children of healthy mothers than in cord blood of children of allergic mothers and decreased TGF-b+ cord blood Tregs in the group of allergic children of allergic mothers compared to all other groups.

• Keywords
• IL-10, TGF-b, Treg, allergy, cord blood, regulatory T cells,
• Publication type
• Journal Article MeSH

Continuous increasing incidence of allergic diseases is calling for identifying early prognostic markers pointing to increased risk of allergy development and establishing protocols for preventive strategies limiting allergy development in predisposed individuals. It is important to better understand the critical events occurring in early postnatal life, especially the interaction of a newborn with microbial compounds important for the maturation of the neonatal immune system and setting immunoregulatory responses as well. Dendritic cells (DC) together with the cytokine microenvironment play an important role in priming of immune responses. The capacity of monocyte-derived DC (moDC) from cord blood of children of healthy and allergic mothers to respond to microbial antigens (Escherichia coli O86 (EcO86) and delipidated Bacillus firmus (DBF)) was tested by flow cytometry and quantitative real-time PCR. Both EcO86 and DBF were able to promote maturation of moDC, but moDC of children of allergic mothers expressed higher levels of activation markers CD80 and CD83. Increased gene expression of IL-6 and lower expression of indol-amine 2,3 dioxygenase were observed in moDC of neonates of allergic mothers, in comparison to healthy ones. A higher gene expression and an increased presence of activation markers on moDC of newborns of allergic mothers indicate a generally higher reactivity of these cells, possibly enabling easier development of inappropriate immune response after an allergen encounter.

• MeSH
• Hypersensitivity blood   diagnosis   MeSH
• Antigens, Bacterial immunology   MeSH
• Antigens, Surface genetics   metabolism   MeSH
• Biomarkers metabolism   MeSH
• Cytokines genetics   metabolism   MeSH
• Dendritic Cells immunology   MeSH
• Fetal Blood MeSH
• Cells, Cultured MeSH
• Humans MeSH
• Mothers MeSH
• Monocytes immunology   MeSH
• Infant, Newborn MeSH
• Check Tag
• Humans MeSH
• Male MeSH
• Infant, Newborn MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Antigens, Bacterial MeSH
• Antigens, Surface MeSH
• Biomarkers MeSH
• Cytokines MeSH

Allergic diseases represent a major issue in clinical and experimental immunology due to their high and increasing incidence worldwide. Allergy status of the mother remains the best predictor of an individual's increased risk of allergy development. Dysregulation of the balance between different branches of immune response, chiefly excessive polarization towards Th2, is the underlying cause of allergic diseases. Regulatory T cells (Tregs) play a pivotal role in the timely establishment of physiological immune polarization and are crucial for control of allergy. In our study we used flow cytometry to assess Tregs in cord blood of newborns of healthy (n = 121) and allergic (n = 108) mothers. We observed a higher percentage of Tregs (CD4+CD25+CD127lowFoxP3+) in cord blood of children of allergic mothers. However, the percentage of cells expressing extracellular (PD-1, CTLA-4, GITR) and intracellular (IL-10, TGF-β) markers of function was lower (significantly for PD-1 and IL-10) within Tregs of these children. Furthermore, Helios- induced Tregs in the cord blood of children of allergic mothers were decreased. These results were supported by a decrease in plasma levels of IL-10 and TGF-β in cord blood of newborns of allergic mothers, implying lower tolerogenic capacity on the systemic level. Taken together, these findings reflect deficient function of Tregs in the group with higher risk of allergy development. This may be caused by a lower maturation status of the immune system, specifically Tregs, at birth. Such immaturity may represent an important mechanism involved in the increased risk of allergy in children of allergic mothers.

• MeSH
• Hypersensitivity blood   immunology   MeSH
• Cytokines blood   MeSH
• Fetal Blood immunology   MeSH
• Immunoglobulin E blood   MeSH
• Humans MeSH
• Mothers MeSH
• Disease Susceptibility blood   immunology   MeSH
• Infant, Newborn MeSH
• T-Lymphocytes, Regulatory immunology   MeSH
• Risk MeSH
• Check Tag
• Humans MeSH
• Infant, Newborn MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Cytokines MeSH
• Immunoglobulin E MeSH

Beneficial effect of maternal milk is acknowledged, but there is still question whether maternal milk from allergic mother is as good as from healthy one. In our study, we have assayed the effect of cells from colostrum of healthy and allergic mothers on gene expression of cytokines in cord blood cells of newborns of healthy and allergic mothers. Cytokines typical for Th1 (IL-2, IFN-gamma), Th2 (IL-4, IL-13), Tregs (IL-10, TGF-beta), and IL-8 were followed. We were not able to detect significant influence of colostral cells on gene expression of cytokines in cord blood after 2-day coculture using Transwell system. There was no difference in gene expression of cytokines in nonstimulated cord blood cells of newborns of healthy and allergic mothers, but generally increased gene expression of cytokines except IL-10 and TGF-beta after polyclonal stimulation was detected in cord blood cells of children of allergic mothers. There was no difference in IL-10 expression in stimulated cord blood cells of children of healthy and allergic mothers. Gene expression of TGF-beta was even decreased in stimulated cord blood cells of children of allergic mothers in comparison to healthy ones. We have not observed difference in the capacity of colostral cells of healthy and allergic mothers to influence gene expression of cytokines in cord blood cells, but we have described difference in the reactivity of cord blood cells between children of allergic and healthy mothers.

• Keywords
• Cord Blood, Cord Blood Cell, Cord Blood Sample, Increase Gene Expression, Regulatory Cytokine,
• MeSH
• Hypersensitivity blood   genetics   immunology   MeSH
• Cytokines blood   MeSH
• Adult MeSH
• Gene Expression MeSH
• Fetal Blood chemistry   immunology   MeSH
• Interleukin-10 genetics   immunology   MeSH
• Interleukin-13 blood   MeSH
• Interleukin-4 blood   MeSH
• Infant MeSH
• Colostrum chemistry   immunology   MeSH
• Humans MeSH
• Young Adult MeSH
• Infant, Newborn MeSH
• Pregnancy MeSH
• Th1 Cells immunology   MeSH
• Th2 Cells immunology   MeSH
• Check Tag
• Adult MeSH
• Infant MeSH
• Humans MeSH
• Young Adult MeSH
• Male MeSH
• Infant, Newborn MeSH
• Pregnancy MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Cytokines MeSH
• Interleukin-10 MeSH
• Interleukin-13 MeSH
• Interleukin-4 MeSH