Chemoattractant factors in breast milk from allergic and nonallergic mothers

The hormonal physiology of immune components in breast milk and their impact on the infant immune response

During pregnancy, the maternal body undergoes a considerable transformation regarding the anatomy, metabolism, and immune profile that, after delivery, allows for protection and nourishment of the offspring via lactation. Pregnancy hormones are responsible for the development and functionality of the mammary gland for breast milk production, but little is known about how hormones control its immune properties. Breast milk composition is highly dynamic, adapting to the nutritional and immunological needs that the infant requires in the first months of life and is responsible for the main immune modeling of breastfed newborns. Therefore, alterations in the mechanisms that control the endocrinology of mammary gland adaptation for lactation could disturb the properties of breast milk that prepare the neonatal immune system to respond to the first immunologic challenges. In modern life, humans are chronically exposed to endocrine disruptors (EDs), which alter the endocrine physiology of mammals, affecting the composition of breast milk and hence the neonatal immune response. In this review, we provide a landscape of the possible role of hormones in the control of passive immunity transferred by breast milk and the possible effect of maternal exposure to EDs on lactation, as well as their impacts on the development of neonatal immunity.

Maternal and Neonatal Factors Modulating Breast Milk Cytokines in the First Month of Lactation

Breast milk (BM) cytokines support and modulate infant immunity, being particularly relevant in premature neonates with adverse outcomes (NAO). This study aimed to examine, in a cohort of Spanish breastfeeding women, changes in BM cytokines in the first month of lactation, their modulation by neonatal factors (sex, gestational age, and NAO), maternal factors (obstetric complications, C-section, and diet), and their relationship with oxidative status. Sixty-three mother-neonate dyads were studied at days 7 and 28 of lactation. Dietary habits were assessed by a 72-h dietary recall, and the maternal dietary inflammatory index (mDII) was calculated. BM cytokines (IL-10, IL-13, IL-8, MCP-1, and TNFα) were assessed by ultra-sensitive chemiluminescence. Total antioxidant capacity was assessed by the ABTS method and lipid peroxidation by the MDA+HNE kit. From days 7 to 28 of lactation, the levels of IL-10 and TNFα remained stable, while IL-13 increased (β = 0.85 ± 0.12, p < 0.001) and IL-8 and MCP-1 levels decreased (β = -0.64 ± 0.27, p = 0.019; β = -0.98 ± 0.22, p < 0.001; respectively). Antioxidant capacity and lipid peroxidation also decrease during lactation. Neonatal sex did not influence any of the cytokines, but BM from mothers with male infants had a higher antioxidant capacity. Gestational age was associated with male sex and NAO, being inversely correlated with the BM proinflammatory cytokines IL-8, MCP-1, and TNFα. From days 7 to 28 of lactation, BM from women with NAO infants increased MCP-1 levels and had a larger drop in antioxidant capacity, with the opposite trend in lipid peroxidation. MCP-1 was also significantly higher in women undergoing C-section; this cytokine declined in women who decreased mDII during lactation, while IL-10 increased. Linear mixed regression models evidenced that the most important factors modulating BM cytokines were lactation period and gestational age. In conclusion, during the first month of lactation, BM cytokines shift towards an anti-inflammatory profile, influenced mainly by prematurity. BM MCP-1 is associated with maternal and neonatal inflammatory processes.

Increased Colostral Concentration of Macrophage Migration Inhibitory Factor in Mothers with Premature Rupture of Membranes

Objective: The colostrum contains macrophage migration inhibitory factor (MIF), which plays an important role in protecting newborns from infections. As such, colostrum may be specifically important to prevent early onset neonatal sepsis among neonates born after premature rupture of membranes (PROM). However, the effect of PROM on the colostral MIF concentration has not been previously described. The aim of this study is to compare the concentration of MIF in the colostrum of mothers with and without PROM. Methods: The study group consisted of 44 women, 22 of whom had PROM. Colostrum was expressed and collected within 72 hours of birth. MIF concentration was measured using the enzyme-linked immunosorbent assay method and compared between mothers with and without PROM. Results: There were no differences between the two groups (PROM group n = 22, control group n = 22) with regard to the age of mothers, mode of delivery, neonatal gestational age, birth weight, and sex of the infants (p > 0.05). The colostral MIF concentration was significantly higher among mothers with than without PROM (p = 0.0001). There was a positive and significant correlation between the colostral MIF concentration and PROM duration (r = 0.314, p = 0.038). Conclusions: PROM was associated with a higher colostral MIF concentration, with this concentration being positively correlated with the duration of PROM. This increased concentration may be important in offering these neonates additional protection against early onset infections, which is a risk associated with PROM.

Probiotic Supplementation and Human Milk Cytokine Profiles in Japanese Women: A Retrospective Study from an Open-Label Pilot Study

The benefits of probiotic supplementation to lactating mothers on human milk cytokines are inconclusive. Thus, we performed a comprehensive open-label pilot trial analysis of 27 human milk cytokines in lactating women with allergies (one to three months postpartum) to determine the effect of supplementation with a mixture of new probiotic strains. Participants voluntarily joined the probiotic (n = 41) or no supplementation control (n = 19) groups. The probiotic group took three probiotic tablets (Lactobacillus casei LC5, Bifidobacterium longum BG7, and Bacillus coagulans SANK70258) daily for one to three months postpartum. Milk samples were collected at one, two, and three months postpartum, and cytokine levels were measured using multiplex assays. The effects were analyzed using multivariate regression models. Eleven cytokines showed a positive rate of over 50% in the milk samples throughout testing in both groups. The positive rates of IL-1 receptor antagonist and IL-7 changed significantly with lactation progression in logistic regression models after adjusting for time and supplementation, whereas rates of other cytokines showed no significant differences. The lactational change patterns of IL-10 concentrations differed significantly between the two groups. A short-term supplementation of probiotics affects human milk cytokine levels in lactating women with a possible placebo effect still existing. Future placebo-controlled studies are needed to support these results, based on the estimated sample sizes in this study.

Influences of Maternal Factors Over Offspring Allergies and the Application for Food Allergy

The prevalence of food allergy has been steadily rising worldwide with the highest incidence noted among younger children, and increasingly recognized as a growing public concern. The first known ingestion of foods often causes allergic reaction, suggesting that sensitization of offspring with food allergens may occur during pregnancy and/or through breastfeeding. This creates a milieu that shapes the neonatal immune responses to these allergens. However, the effects of maternal allergen exposure and maternal sensitization with allergens on development of allergies in offspring remain controversial. This review discusses recent advances from human data in our understanding of how maternal factors, namely, food allergens, allergen-specific immunoglobulins, cytokines, genetics, and environmental factors transferred during pregnancy or breastfeeding influence offspring allergies and how such effects may be applicable to food allergy. Based on information obtained from mouse models of asthma and food allergy, the review also dissects the mechanisms by which maternal factors, including the impact of immune complexes, transforming growth factor-β, vitamin A, and regulatory T-cell responses, contribute to the induction of neonatal tolerance vs. development of allergic responses to maternally transferred allergens.

γδ T cells are the predominant T cell type in opossum mammaries during lactation

Milk provides mammalian neonates with nutritional support and passive immunity. This is particularly true in marsupials where young are born highly altricial and lacking many components of a fully functional adaptive immune system. Here we investigated the T cell populations in the mammaries of a lactating marsupial, the gray short-tailed opossum Monodelphis domestica. Immunohistochemistry confirmed the presence of T cells within the opossum mammaries throughout lactation. Results of quantifying transcript abundance for lymphocyte markers are consistent with γδ T cells being the most common T cell type within lactating mammaries. Numbers of γδ T cells appear to peak early during the first postnatal week, and then decline throughout lactation until weaning. In contrast, numbers of αβ T cells and γμ T cells appear to be low to non-existent in the lactating mammaries. The results support an ancient and conserved role of immune cells in the evolution and function of mammalian mammary tissue.

Distribution of bioactive factors in human milk samples

Background

Breast milk provides nutrition for infants and also contains a variety of bioactive factors that influence the development of the newborn. Human milk is a complex biological fluid that can be separated into different layers (water phase and lipid phase with its component water and lipid fractions). It can affect the developing human body along the whole length of the gastrointestinal tract, and through the circulation, its factors may reach every organ.

Methods

In the present study, we analyzed milk samples collected monthly for 6 months from 16 mothers from the 4^th week postpartum between 2014 and 2016 in Baranya County, Hungary. The 96 samples provided us information about the fluctuation of certain bioactive factors during the first 6 months of lactation. We investigated with Luminex technology the concentrations of several cytokines (CD40, Flt-3L), chemokines (MCP-1, RANTES, GRO, MIP-1ß, MDC, eotaxin, fractalkine), and epidermal growth factor (EGF). Paired t-tests and one-way ANOVA followed by Bonferroni post-hoc tests were used to compare the data.

Results

We detected the presence of each bioactive factor in every layer of the milk samples during the first 6 months of breastfeeding in widespread concentration ranges. In the case of GRO, MIP-1ß, MDC, Flt-3L, fractalkine, and eotaxin, the concentrations were constant during the first 6 months of lactation. The water phase of human milk contained higher factor concentrations compared to both fractions of the lipid phase for most factors (except eotaxin and MIP-1ß). The concentrations of CD40, EGF, MCP-1, and RANTES in the first 3 months were significantly different compared to the values detected between 4^th and 6^th months. In the water phase, the level of MCP-1 was significantly decreased, while all of the other factors increased during the 4^th through 6^th months. We found significantly higher EGF, GRO, and RANTES levels in the water fraction compared to the lipid fraction of the lipid phase.

Conclusions

The novel findings of this investigation were the presence of Flt-3L and MDC in all layers of breast milk, and nearly all bioactive factors in the lipid phase. Due to their widespread physiological effects these factors may have an essential role in organogenesis.

Immune components of early breastmilk: Association with maternal factors and with reported food allergy in childhood

BACKGROUND

Breastmilk (BM) may participate in driving gut barrier function and immunity in the neonate. We analyzed immune and growth factor concentrations in early BM and their association with maternal/environmental characteristics and with food allergy (FA) in childhood.

METHODS

One BM sample was collected in maternity from some mothers in the EDEN birth cohort (n = 2002 mother-child dyads). A random selection was performed among available samples (subcohort, n = 272), for which all deliveries were full-term, various maternal/environmental characteristics were recorded, and parents answered yearly the question "Has a medical doctor diagnosed a FA in your child?" (26 parent-reported FA cases). Only samples collected between day 2 and day 6 post-partum were considered for descriptive analysis (n = 263). Samples for all other FA cases available were added to the subcohort (46 additional cases; "casecohort" design). Fifty cytokines, antibodies, and growth factor concentrations were determined using multiplexed kits and analyzed using robust statistical procedures.

RESULTS

BM components exhibited wide concentration ranges and global day-to-day variation. Different clusters of correlated factors appeared, with components from the main cluster related to maternal diet during pregnancy. Primiparity was positively associated with eleven other components, whereas other factors (eg, maternal atopy and smoking) were related to fewer components. Finally, the casecohort design highlighted a positive association between CXCL10, TNFβ, and IL-2 concentrations and reported FA in childhood.

CONCLUSION

Beyond the unique description of early BM composition, we show that immune information transmitted to the neonate is related to various maternal factors and identified components associated with FA diagnosis in childhood.

Immunologically Active Components in Human Milk and Development of Atopic Disease, With Emphasis on Food Allergy, in the Pediatric Population

Breast-feeding is currently recommended to prevent the development of allergic diseases; however, data are conflicting and mechanisms are unclear. The immunomodulatory composition of human milk is poorly characterized and varies between mothers. We and others have shown that high levels of human milk IgA and certain cytokines and human milk oligosaccharides are associated with protection against food allergy in the infant, but it is unclear whether they are responsible for or simply biomarkers of the vertical transfer of protection. Because human milk has pre- and probiotic properties, the anti-allergy protection afforded by human milk may be due to its control on the developing gut microbiome. In mice, murine milk IgA supports gut homeostasis and shapes the microbiota, which in turn diversifies the intestinal IgA repertoire that reciprocally promotes the diversity of gut microbiome; these mechanisms are poorly understood in humans. In addition, several human milk bioactives are immunostimulatory, which may in part provide protection against allergic diseases. The regulation of immunologically active components in human milk is incompletely understood, although accumulating evidence suggests that IgA and cytokines in human milk reflect maternal exposures. This review summarizes the current literature on human milk components that have been associated with protection against food allergy and related allergic disorders in early childhood and discusses the work relating to regulation of these levels in human milk and possible mechanisms of action.

Leukocytes in expressed breast milk of asthmatic mothers

OBJECTIVE

Infants are born immunologically immature. However, breastfeeding mothers retain an immunological link to their infants. While it is generally accepted that infants are at an immunological advantage when compared with formula-fed infants, the benefit of long-term exclusive breastfeeding by atopic mothers remains controversial. Inconsistency in the conferral of benefit may be due to differences in the immunological constituents passed to the recipient infant. The aim of this investigation was to examine the profile of human milk cells and cytokines from asthmatic compared to non-asthmatic mothers.

METHODS

Twenty-five exclusively breastfeeding mothers with a clinical diagnosis of asthma were postpartum age matched in a double-control 2:1 design with 50 non-asthmatic controls. Each mother provided a single milk sample which was assayed for cell differential by flow cytometry, for ex vivo cytokine production in culture and for aqueous phase cytokines.

RESULTS

Milks from asthmatic mothers differed from non-asthmatics in that they contained a higher proportion of polymorphonuclear (PMN) cells and lower proportion of lymphocytes, predominantly CD3⁺/CD4⁺ T helper cells, reflected by a decrease in the chemokine CCL5 in the milk aqueous phase. More PMN and lymphocytes from asthmatic mothers expressed the adhesion molecule CD11b and lymphocytes the IgE receptor CD23, than those from non-asthmatic mothers.

CONCLUSIONS

Changes to human milk leucocyte prevalence, activation state and cytokines due to maternal asthma may result in changes to immunological priming in the infant. Consequently, the protective effect of long-term breastfeeding may be altered in these mother-infant pairs.

What's Normal? Immune Profiling of Human Milk from Healthy Women Living in Different Geographical and Socioeconomic Settings

Human milk provides a very wide range of nutrients and bioactive components, including immune factors, human milk oligosaccharides, and a commensal microbiota. These factors are essential for interconnected processes including immunity programming and the development of a normal infant gastrointestinal microbiome. Newborn immune protection mostly relies on maternal immune factors provided through milk. However, studies dealing with an in-depth profiling of the different immune compounds present in human milk and with the assessment of their natural variation in healthy women from different populations are scarce. In this context, the objective of this work was the detection and quantification of a wide array of immune compounds, including innate immunity factors (IL1β, IL6, IL12, INFγ, TNFα), acquired immunity factors (IL2, IL4, IL10, IL13, IL17), chemokines (IL8, Groα, MCP1, MIP1β), growth factors [IL5, IL7, epidermal growth factor (EGF), granulocyte colony-stimulating factor, granulocyte-macrophage colony-stimulating factor, TGFβ2], and immunoglobulins (IgA, IgG, IgM), in milk produced by healthy women of different ethnicities living in different geographic, dietary, socioeconomic, and environmental settings. Among the analyzed factors, IgA, IgG, IgM, EGF, TGFβ2, IL7, IL8, Groα, and MIP1β were detected in all or most of the samples collected in each population and, therefore, this specific set of compounds might be considered as the "core" soluble immune factors in milk produced by healthy women worldwide. This approach may help define which immune factors are (or are not) common in milk produced by women living in various conditions, and to identify host, lifestyle, and environmental factors that affect the immunological composition of this complex biological fluid. Clinical Trial Registration: www.ClinicalTrials.gov, identifier NCT02670278.

Does Breast-feeding Relate to Development of Atopic Dermatitis in Young Korean Children?: Based on the Fourth and Fifth Korea National Health and Nutrition Examination Survey 2007-2012

Purpose

There have been conflicting reports concerning the relationship between breast-feeding and the development of atopic dermatitis (AD) in early childhood. The objective of this study was to investigate the associations between breast-feeding and the risk of AD in early childhood in Korea.

Methods

We combined the fourth and fifth Korea National Health and Nutrition Examination Survey data collected from 2007 to 2012 and analyzed 2,015 children at 1 to 3 years old. Regression analysis was used to determine the association of the following variables: AD, feeding types, duration of breast-feeding, and others.

Results

The annual prevalence of exclusive breast-feeding and AD decreased. Parents with allergic diseases preferred breast-feeding and extended duration of feeding compared with those without. In multiple logistic regression analyses, exclusive breast-feeding in feeding type I (P=0.070; adjusted odds ratio [OR]=1.990), exclusive breast-feeding in feeding type II (P=0.095; adjusted OR=1.495) and breast-feeding duration (P=0.430; adjusted OR=1.013) were not significantly related to AD.

Conclusions

Breast-feeding was not found to be associated with an occurrence of AD in young children. Rather, parents with histories of allergic diseases tended to prefer breast-feeding and extend its duration. To clarify the role of breast-feeding in the development of AD, a nation-wide prospective study is needed.

High breast milk IL-1β level is associated with reduced risk of childhood eczema

BACKGROUND

We recently demonstrated a dual effect of breastfeeding with increased risk of eczema and decreased risk of wheezing in early childhood by increasing breastfeeding length. We hypothesize that immune mediators in breast milk could explain such association either through a direct effect or as a surrogate marker of maternal immune constitution.

OBJECTIVE

To investigate the possible association between cytokine and chemokine levels in breast milk and development of eczema and recurrent wheeze during early childhood.

METHODS

Levels of 19 pro-inflammatory and immunoregulatory cytokines and chemokines were measured in 223 breast milk samples from mothers in the Copenhagen Prospective Study on Asthma in Childhood2000 (COPSAC) high-risk birth cohort. Eczema and recurrent wheeze at the age of 0-3 years were prospectively diagnosed by COPSAC physicians adherent to predefined validated algorithms. Association analyses were performed by Cox regression adjusting for potential confounding factors and by multivariable principal component analysis.

RESULTS

Increased IL-1β in breast milk (≥ 0.7 pg/mL) was associated with more than a halved risk of eczema before age three (aHR = 0.41; 95% CI = 0.24-0.68; P < 0.001), which remained significant after false discovery rate adjustment (P = 0.008). The principal component analysis confirmed that a mediator pattern dominated by high levels of IL-1β, IL-17A, and CCL17 and low levels of CXCL1 and TSLP in breast milk protected against eczema (aHR = 0.82; 95% CI = 0.68-0.98; P = 0.03). No associations were observed for recurrent wheeze.

CONCLUSIONS AND CLINICAL RELEVANCE

Elevated breast milk IL-1β level was associated with decreased risk of early childhood eczema suggesting either a direct protective effect of IL-1β or IL-1b acting as a proxy for a healthy maternal immune system protecting high-risk offspring from eczema.

Role of Maternal Allergy on Immune Markers in Colostrum and Secretory Immunoglobulin A in Stools of Breastfed Infants

BACKGROUND

Although protection against infectious diseases has been observed among breastfed infants as compared to formula-fed infants, possible benefits of breastfeeding by allergic mothers for allergy prevention remain controversial.

OBJECTIVES

The aims of this study were to determine whether maternal allergy would influence immune markers (secretory immunoglobulin A [sIgA], interleukin-8 [IL-8], soluble CD14 [sCD14]) in colostrum and the associations between maternal allergy and fecal sIgA levels in breastfed infants.

METHODS

Study subjects were enrolled from the Prediction of Allergies in Taiwanese Children (PATCH) birth cohort study. Colostrum samples were obtained from 98 lactating mothers. Stool samples were collected from 108 infants within 5 days after birth and at 2 and 4 months of age. We compared concentrations of sIgA, IL-8, and sCD14 in colostrum between mothers with and without a history of allergic disease and allergic sensitization. We also compared fecal sIgA levels between breastfed and formula-fed infants and between infants with allergic and nonallergic mothers.

RESULTS

The sIgA concentrations were significantly higher in colostrum from allergic mothers than from nonallergic mothers (P = .01) and from allergic mothers who were immunoglobulin E (IgE) sensitized compared to nonallergic mothers who were not IgE sensitized (P = .023). Breastfed infants had significantly higher fecal sIgA levels as compared to formula-fed infants, regardless of whether their lactating mothers had an allergy (P < .05).

CONCLUSION

We found that breastfeeding is associated with increased infants' fecal sIgA levels and may have potential protective effects to the infants during the first 4 months of life, regardless of whether their lactating mothers have allergies.

Breast Milk and Solid Food Shaping Intestinal Immunity

After birth, the intestinal immune system enters a critical developmental stage, in which tolerogenic and pro-inflammatory cells emerge to contribute to the overall health of the host. The neonatal health is continuously challenged by microbial colonization and food intake, first in the form of breast milk or formula and later in the form of solid food. The microbiota and dietary compounds shape the newborn immune system, which acquires the ability to induce tolerance against innocuous antigens or induce pro-inflammatory immune responses against pathogens. Disruption of these homeostatic mechanisms might lead to undesired immune reactions, such as food allergies and inflammatory bowel disease. Hence, a proper education and maturation of the intestinal immune system is likely important to maintain life-long intestinal homeostasis. In this review, the most recent literature regarding the effects of dietary compounds in the development of the intestinal immune system are discussed.

Soluble immunoglobulin A in breast milk is inversely associated with atopic dermatitis at early age: the PASTURE cohort study

BACKGROUND

The role of breastfeeding for the development of atopic diseases in childhood is contradictory. This might be due to differences in the composition of breast milk and levels of antimicrobial and anti-inflammatory components.

OBJECTIVE

The objective of this study was to examine whether levels of total immunoglobulin A (IgA) or transforming growth factor-β1 (TGF-β1) in breast milk were associated with the risk of developing atopic dermatitis (AD), atopic sensitization or asthma at early age taking breastfeeding duration into account.

METHODS

The birth cohort study PASTURE conducted in Finland, France, Germany and Switzerland provided 610 breast milk samples collected 2 months after delivery in which soluble IgA (sIgA) and TGF-β1 levels were measured by ELISA. Duration of breastfeeding was assessed using weekly food frequency diaries from month 3 to month 12. Data on environmental factors, AD and asthma were collected by questionnaires from pregnancy up to age 6. Atopic status was defined by specific IgE levels in blood collected at the ages of 4 and 6 years. Multivariate logistic regression models were used for statistical analysis.

RESULTS

Soluble IgA and TGF-β1 levels in breast milk differed between countries, and sIgA levels were associated with environmental factors related to microbial load, for example, contact to farm animals or cats during pregnancy, but not with raw milk consumption. sIgA levels were inversely associated with AD up to the of age 2 years (P-value for adjusted linear trend: 0.005), independent of breastfeeding duration. The dose of sIgA ingested in the first year of life was associated with reduced risk of AD up to the age of 2 (aOR, 95% CI: 0.74; 0.55-0.99) and 4 years (0.73; 0.55-0.96). No clear associations between sIgA and atopy or asthma up to age 6 were observed. TGF-β1 showed no consistent association with any investigated health outcome.

CONCLUSION AND CLINICAL RELEVANCE

IgA in breast milk might protect against the development of AD.

Differences in exosome populations in human breast milk in relation to allergic sensitization and lifestyle

BACKGROUND

Breast-feeding has many beneficial effects on the developing immune system of the newborn. Breast milk contains immunoregulatory factors, such as nano-sized vesicles named exosomes. This study aimed at characterizing breast milk exosomes from human early milk and mature milk and to investigate whether allergic sensitization and an anthroposophic lifestyle could influence the exosome profile.

METHODS

Breast milk was collected from 22 mothers at day 3-8 and from 61 mothers at 2 months postpartum, all part of the ALADDIN birth cohort. Isolated exosomes were captured on anti-MHC-class II- or anti-CD63 beads and analyzed by flow cytometry. Exosomal phenotype was related to lifestyle and allergic sensitization of the mothers, and sensitization of the child at 2 years of age.

RESULTS

We found a higher content of exosomes in early milk compared with mature milk. Early milk exosomes were enriched in HLA-DR molecules and displayed significantly lower levels of HLA-ABC compared with those in mature milk. Phenotypically different subpopulations of exosomes were found in mature milk. Significantly lower levels of MUC1 were detected on CD63-enriched exosomes from sensitized mothers compared with nonsensitized. Furthermore, women with an anthroposophic lifestyle had significantly lower MUC1 expression on their HLA-DR-enriched milk exosomes and up-regulated levels of CD63 on CD63-enriched exosomes compared with nonanthroposophic mothers. Notably, mothers whose children developed sensitization had an increased amount of HLA-ABC on their milk exosomes enriched for CD63.

CONCLUSIONS

The phenotype of exosomes in breast milk varies with maternal sensitization and lifestyle, which might influence allergy development in the child.

Serum levels of the CC chemokines CCL2, CCL5, and CCL11 in food allergic children with different clinical manifestations

Food allergies (FA) are frequent in 8 % of children under 3 years old and approximately 2 % of adults. Chemokine are involved in various allergies such as FA. The present study was aimed to determine CCL2, CCL5, and CCL11 levels in FA. The study population of this cross-sectional study contained 63 patients suffering from FA and 100 healthy controls. Concentrations of CCL2, CCL5, CCL11, and IgE were measured by enzyme-linked immunosorbent assay (ELISA). Eosinophils were counted using Casy Ι cell counter + analyzer system model SCAREF system GmbH. Differences were considered significant at P < 0.05. Current results showed that FA patients had significantly elevated numbers of circulating periphery eosinophils than the disease-free controls. Serum IgE levels in FA patients were also higher than controls. We also showed that serum levels of CCL2 and CCL11 were significantly enhanced in FA patients compared to control but CCL5 was not detectable. Results of present study revealed that both CCL2 and CCL11 were more elevated in FA children suffering from anaphylaxis and urticaria than bronchial asthma and atopic dermatitis. These results also indicated that more increased levels of CCL2 and CCL11 were observed following consumption of cow's milk and pistachio nuts. Overall, findings of the present study proposed that serum levels of CCL2 and CCL11 are elevated in FA and these may be considered as useful parameters in diagnosis of disorder. It is also possible to design treatments on the basis of blocking of chemokines expression by application of antibodies against them to overcome allergic complications in patients suffering from FA.

Effects of synbiotic supplementation on breast milk levels of IgA, TGF-β1, and TGF-β2

BACKGROUND

Effects of probiotics on the immunological composition of breast milk have been investigated in a few previous studies.

OBJECTIVES

The aims of this study were to determine the effects of synbiotic (probiotic plus prebiotic) supplementation on immunoglobulin A (IgA), transforming growth factor β1 (TGF-β1), and transforming growth factor β2 (TGF-β2) levels of breast milk and on diarrhea incidence in infants.

METHODS

In this randomized, double-blind, and placebo-controlled trial, we recruited 80 lactating mothers who were exclusively breastfeeding their 3-month-old infants. We randomly divided the mothers into 2 groups to receive a daily synbiotic supplement (n = 40) or a placebo (n = 40) for 30 days. Demographic and clinical data (ie, health status) were obtained through an interview. The IgA levels of breast milk were detected by nephelometry, and the levels of TGF-β1 and TGF-β2 were measured using a commercial Platinum ELISA kit.

RESULTS

The breast milk IgA increased significantly from 0.41 ± 0.09 to 0.48 ± 0.15 g/L in the supplemented group (P = .018), while in the placebo group, no significant changes were observed. Although the breast milk TGF-β1 levels did not change significantly, the TGF-β2 levels of breast milk increased significantly from 270 ± 37.8 to 382 ± 43.7 pg/mL in the supplemented group (P = .043). Also, the incidence of diarrhea in infants decreased significantly in the supplemented group while no significant changes were observed in the placebo group after the experimental period.

CONCLUSION

Synbiotic supplementation may have positive effects on the immune composition of breast milk and the reduction of diarrhea incidence in infants.

Pre- and perinatal characteristics and breast milk immune markers

BACKGROUND

Maternal allergy and gestational exposures can alter the concentration of type-1/type-2/T-regulatory markers in breast milk. We tested whether maternal risk factors are related to breast milk immune markers.

METHODS

Expecting mothers were enrolled in 2008-2010 in South Carolina in prenatal clinics and classes. Interferon (IFN)-γ-induced protein 10 (CXCL10), CCL11, interleukin (IL)-1β, IL-4, IL-5, IL-6, CXCL8, IL-10, IL-12(p70), IL-13, transforming growth factor (TGF)-β1, and immunoglobulin (Ig)A in 115 whey samples were measured by immunoassays. Maternal asthma, eczema, rhinitis, smoking, urogenital infections during gestation, pet exposure, education, race/ethnicity, age, body mass, and the child's birth date and sex were ascertained. The effects of these risk factors on immune markers were estimated using general linear models.

RESULTS

Maternal asthma was linked to higher levels of IL-5, rhinitis to lower levels of IL-5 and INF-γ, and eczema to lower levels of IL-6. Gestational smoking was related to increased concentrations of CXCL8 and IL-6. African-American mothers had markedly higher levels of IL-6, IFN-γ, and CXCL8. Urogenital infections, maternal age, body mass, child's sex, and season of birth contributed to the variation.

CONCLUSION

The impact of maternal allergies on immune markers in breast milk was small compared with that of maternal nondisease characteristics.

Presence of IL-9 in paired samples of human colostrum and transitional milk

BACKGROUND

Human colostrum and breast milk are known to contain high levels of cytokines, cytokine receptors, and chemokines.

OBJECTIVE

To investigate the presence and compare levels of soluble cytokines in paired samples of human colostrum and milk.

METHODS

Levels of 27 cytokines were measured in 9 paired samples of human colostrum (day 2 after delivery) and breast milk (day 4 or 5 after delivery) by using multiplex technology.

RESULTS

The majority of cytokines and chemokines investigated have been previously described in colostrum and/or breast milk. For the first time, we describe the presence of IL-9 in both human colostrum and milk. Of the 27 cytokines investigated, only IL-5 was absent in both colostrum and milk, whereas IL-1β, IL-2, IL-4, IL-15, IL-17, and MIP-1α were present in colostrum, but not in breast milk. In general, colostrum contained higher concentrations of cytokines with respect to human milk.

CONCLUSION

Our data confirm and expand previous studies showing that human colostrum and breast milk are rich in cytokines and chemokines, including IL-9, which might contribute to the development of the immune system of the newborn.

Presence of CTAK/CCL27, MCP-3/CCL7 and LIF in human colostrum and breast milk

Human colostrum and breast milk are known to contain high levels of cytokines and chemokines, which are thought to contribute to the development of the newborn. The aim of this study was to investigate the difference in the presence and levels of 21 soluble cytokines and chemokines in paired samples of human colostrum (day 2 after delivery) and breast milk (day 4-5 after delivery) by using the multiplex technology. Of the 21 cytokine investigated in 10 pairs of samples, only β-NGF was absent in both colostrum and milk, while INF-α2, SCF and TNF-β were present in colostrum but not in human milk. As a general rule, colostrum contained higher concentrations of cytokines and chemokines with respect to breast milk. The majority of cytokines, detected in colostrum alone or in colostrum and human milk (IL-1α, IL-2Rα, IL-3, IL-16, IL-18, GRO-α, HGF, IFN-α2, M-CSF, MIF, MIG, TNF-β, SDF-1α, TRAIL) have been described in previous studies, while for the first time we describe the presence of additional cytokines either in colostrum alone (SCF) or in both colostrum and breast milk (CTAK/CCL27, MCP-3/CCL7, LIF). Our data confirm and expand previous studies showing that some cytokines/chemokines, which might contribute to the development of the gastro-intestinal and nervous systems, are overexpressed in human colostrum and breast milk, and might contribute to the development of these systems.

Maternal immune markers in serum during gestation and in breast milk and the risk of asthma-like symptoms at ages 6 and 12 months: a longitudinal study

Background

The role of breast milk on the risk of childhood asthma is in dispute. The aim of this prospective study is to determine the relationship of immune markers in maternal serum during gestation and breast milk to asthma-like symptoms (AS) in infancy.

Methods

Pregnant women were recruited in Columbia and Charleston, South Carolina. Blood (median: three weeks before delivery) and breast milk (three weeks after delivery) samples were collected. Concentrations of interferon (IFN)-γ, IFN gamma-induced protein 10 (IP-10 or CXCL10), CCL11, interleukin (IL) 1β, IL-4, IL-5, IL-6, CXCL8, IL-10, IL-12(p70), IL-13, transforming growth factor (TGF)-β1, and immunoglobulin (Ig) A in both maternal serum and milk whey were determined via immunoassays. Asthma-like symptoms (AS) of the infant were ascertained at 6 and 12 months, respectively. Generalized estimating equations assessed relative risks (RRs) of immune markers for repeated measurements of AS, considering intra-individual correlations and adjusting for confounders. To provide comparable risk estimates, quartiles of the immune markers were used, except for IL-5 in whey and IgA in serum, which were dichotomized.

Results

Of 178 women, 161 provided blood and 115 breast milk samples. IL-12(p70), IL-4, IL-10, IL-1β, and CCL11 in serum and in whey were not further considered for the statistical analyses since the proportion of non-detectable values was high. Most immune markers in serum and milk whey were moderately or highly correlated; however, IgA was negatively correlated. Infants in the highest quartile of IL-13 in both serum and whey were at a higher risk of AS (RR = 3.02 and 4.18; respectively) compared to infants in the first quartile. High levels of IL-5 in serum and whey was also identified as a risk. In addition, increased secretory IgA and TGF-β1 in breast milk reduced the risks of AS.

Conclusions

Maternal serum and whey levels of IL-5 and IL-13 are risk markers for AS; whey IgA and TGF-β1 seem to be protective. Only focusing on breast milk portend that milk cytokines IL-5 and IL-13 have adverse effects. However, similar immune exposures during late gestation and via milk suggest that both may enhance AS among infants.

Differential transmission of HIV traversing fetal oral/intestinal epithelia and adult oral epithelia

While human immunodeficiency virus (HIV) transmission through the adult oral route is rare, mother-to-child transmission (MTCT) through the neonatal/infant oral and/or gastrointestinal route is common. To study the mechanisms of cell-free and cell-associated HIV transmission across adult oral and neonatal/infant oral/intestinal epithelia, we established ex vivo organ tissue model systems of adult and fetal origin. Given the similarity of neonatal and fetal oral epithelia with respect to epithelial stratification and density of HIV-susceptible immune cells, we used fetal oral the epithelium as a model for neonatal/infant oral epithelium. We found that cell-free HIV traversed fetal oral and intestinal epithelia and infected HIV-susceptible CD4(+) T lymphocytes, Langerhans/dendritic cells, and macrophages. To study the penetration of cell-associated virus into fetal oral and intestinal epithelia, HIV-infected macrophages and lymphocytes were added to the surfaces of fetal oral and intestinal epithelia. HIV-infected macrophages, but not lymphocytes, transmigrated across fetal oral epithelia. HIV-infected macrophages and, to a lesser extent, lymphocytes transmigrated across fetal intestinal epithelia. In contrast to the fetal oral/intestinal epithelia, cell-free HIV transmigration through adult oral epithelia was inefficient and virions did not infect intraepithelial and subepithelial HIV-susceptible cells. In addition, HIV-infected macrophages and lymphocytes did not transmigrate through intact adult oral epithelia. Transmigration of cell-free and cell-associated HIV across the fetal oral/intestinal mucosal epithelium may serve as an initial mechanism for HIV MTCT.

Premature delivery influences the immunological composition of colostrum and transitional and mature human milk

Human breast milk is the ideal nutrition for the newborn, and in addition to its nutritional contribution, necessary for infant growth and development, it contains various immune bioactive factors that confer some of the numerous beneficial effects of breastfeeding. The current study analyzed the concentrations of IgA, growth factors such as epidermal growth factor (EGF), TGFβ1, and TGFβ2, cytokines IL-6, IL-8, IL-10, IL-13, and TNFα, and TNF-receptor I (TNF-RI) in colostrum and transitional and mature milk from mothers with mature, premature, and very premature infants. Human milk samples were collected from mothers delivering at term (T), preterm (PT), and very preterm (VPT). Milk from all the mothers was collected at 3 different time points after delivery corresponding to colostrum and transitional and mature milk. After obtaining milk whey, IgA, EGF, TGFβ1, and TGFβ2 were determined by ELISA and IL-6, IL-8, IL-10, IL-13, TNFα and TNF-RI by cytometric bead array immunoassay. The colostrum of the PT group was extremely rich in most of the factors studied, but higher concentrations than in the T group were only found for IL-6 (P = 0.051), TGFβ1, and TGFβ2 (P < 0.05). Conversely, the colostrum of the VPT group had lower concentrations of IgA, IL-8, IL-10, and TNFα than those in the T group (P < 0.05). Results suggest that maternal lactogenic compensatory mechanisms accelerating the development of immature breast-fed preterm infants may take effect only after wk 30 of gestation.

Immune markers in breast milk and fetal and maternal body fluids: a systematic review of perinatal concentrations

Breastfeeding represents the continued exposure of the infant to the maternal immune environment.Uterine, perinatal, and postnatal exposure to immune factors may contribute to an infant’s risk of developing immune-mediated disorders, including allergies. A PubMed search was conducted to review studies in humans and analyze concentrations of immune markers (TGF-beta, IFN-gamma, eotaxin, CCL5, CXCL10, TNF-alpha, MCP-1, IL-1beta, IL-4, IL-5, IL-6,IL-8, IL-10, IL-12, IL-13, sCD14, sIgA, IgG4, IgM) found in maternal serum, amniotic fluid, cord serum, colostrum, transition and mature milk. Concentrations of immune markers showed large variations across samples and studies. Reports documented conflicting results. Small sample sizes, differences in population characteristics, inconsistent sample collection times, and various sample collection and measurement methods may have led to wide variations in the concentrations of immune markers. Studies analyzing the associations between immune markers in maternal fluids and infant allergies remain inconclusive because of gaps in knowledge and a lack of standardized methods.

Characterization of immunocompetent cells in human milk of Han Chinese

Immunocompetent cells in colostrum and mature breast milk (42 days after delivery) of 64 Chinese females of Han ethnic background were characterized. The total cell numbers in colostrum and mature breast milk were 593 ± 205 × 10(6)/L and 1.74 ± 0.97 × 10(6)/L, respectively. NK cell is the predominant lymphocyte subtype (12.69%). T cells in colostrum express CD40L and CD25 without stimulation, indicating memory T cells in nature. The CD45RA( +)CD45RO(+) subsets of CD4(+) T cells are present in both colostrum and mature human milk. The percentage of NK cells and the absolute number of CD4(+)CD45RO(+) T cells in colostrum of atopic mothers were significantly lower than those of mothers without atopy (P = .006 and .026, respectively). The absolute numbers of CD4( +) T lymphocytes and their expression of CD40L were significantly reduced in breast milk of mothers who had undergone cesarean section versus vaginal delivery (P < .05), indicating that atopy and cesarean delivery are associated with the phenotypes of lymphocytes in colostrum.

Maternal country of origin, breast milk characteristics and potential influences on immunity in offspring

Breast milk contains pro- and anti-inflammatory cytokines and chemokines with potential to influence immunological maturation in the child. We have shown previously that country of birth is associated with the cytokine/chemokine profile of breast milk. In this study we have investigated how these differences in breast milk affect the cellular response of cord blood mononuclear cells (CBMCs) and intestinal epithelial cells (IECs, cell line HT-29) to microbial challenge. Ninety-five women were included: 30 from Mali in West Africa, 32 Swedish immigrants and 33 native Swedish women. CBMCs or IECs were stimulated in vitro with breast milk, alone or in combination with lipopolysaccharide (LPS) or peptidoglycan (PGN). Breast milk in general abrogated the LPS-induced down-regulation of surface CD14 and Toll-like receptor (TLR)-4 expression on CB monocytes, while inhibiting the PGN-induced TLR-2 up-regulation. However, breast milk from immigrant women together with LPS induced a lower CBMC release of interleukin (IL)-6 (P = 0·034) and CXCL-8/IL-8 (P = 0·037) compared with breast milk from Swedish women, while breast milk from Swedish women and Mali women tended to increase the response. The same pattern of CXCL-8/IL-8 release could be seen after stimulation of IECs (HT-29). The lower CBMC and IEC (HT-29) responses to microbial compounds by breast milk from immigrant women could be explained by the fact that breast milk from the immigrant group showed a divergent pro- and anti-inflammatory content for CXCL-8/IL-8, transforming growth factor-β1 and soluble CD14, compared to the other two groups of women. This may have implications for maturation of their children's immune responses.

Breast milk cytokine and IgA composition differ in Estonian and Swedish mothers-relationship to microbial pressure and infant allergy

The immune system of the neonate is influenced by maternal immunity during pregnancy and lactation. An altered microbial exposure, possibly underlying the increase of allergic diseases in affluent societies, may affect maternal breast milk immune composition. Secretory IgA (SIgA), IL-4, IL-10, IL-13, IFN-[gamma], TGF-[beta]1, and TGF-[beta]2 were analyzed with ELISA in colostrum and 1-mo mature milk from mothers from Estonia (n = 39) and Sweden (n = 60), the two geographically adjacent countries with different living conditions and allergy incidence. The IL-10 and IFN-[gamma] levels were higher in colostrum from Estonian than Swedish mothers, whereas the opposite was true for TGF-[beta]2. In mature milk, higher SIgA and IFN-[gamma] levels but lower TGF-[beta]1 and TGF-[beta]2 levels were observed in Estonian than Swedish mothers. Interestingly, in Sweden but not Estonia, the TGF-[beta]1 and TGF-[beta]2 levels correlated inversely with environmental endotoxin concentrations, whereas positive correlations to microbial load were observed for IL-4, IL-10, and IFN-[gamma]. High colostral IL-13 levels were associated with allergic sensitization during infancy in Sweden. In conclusion, Estonian mothers have lower breast milk levels of TGF-[beta], particularly TGF-[beta]2, but higher levels of SIgA, IL-10, and IFN-[gamma] than Swedish mothers, possibly because of differences in microbial load.

c-Jun induces mammary epithelial cellular invasion and breast cancer stem cell expansion

The molecular mechanisms governing breast tumor cellular self-renewal contribute to breast cancer progression and therapeutic resistance. The ErbB2 oncogene is overexpressed in approximately 30% of human breast cancers. c-Jun, the first cellular proto-oncogene, is overexpressed in human breast cancer. However, the role of endogenous c-Jun in mammary tumor progression is unknown. Herein, transgenic mice expressing the mammary gland-targeted ErbB2 oncogene were crossed with c-jun(f/f) transgenic mice to determine the role of endogenous c-Jun in mammary tumor invasion and stem cell function. The excision of c-jun by Cre recombinase reduced cellular migration, invasion, and mammosphere formation of ErbB2-induced mammary tumors. Proteomic analysis identified a subset of secreted proteins (stem cell factor (SCF) and CCL5) induced by ErbB2 expression that were dependent upon endogenous c-Jun expression. SCF and CCL5 were identified as transcriptionally induced by c-Jun. CCL5 rescued the c-Jun-deficient breast tumor cellular invasion phenotype. SCF rescued the c-Jun-deficient mammosphere production. Endogenous c-Jun thus contributes to ErbB2-induced mammary tumor cell invasion and self-renewal.

Effect of breastfeeding duration on lung function at age 10 years: a prospective birth cohort study

INTRODUCTION

The protective effects of breastfeeding on early life respiratory infections are established, but there have been conflicting reports on protection from asthma in late childhood. The association of breastfeeding duration and lung function was assessed in 10-year-old children.

METHODS

In the Isle of Wight birth cohort (n = 1456), breastfeeding practices and duration were prospectively assessed at birth and at subsequent follow-up visits (1 and 2 years). Breastfeeding duration was categorised as "not breastfed" (n = 196); "<2 months" (n = 243); "2 to <4 months" (n = 142) and ">or=4 months" (n = 374). Lung function was measured at age 10 years (n = 1033): forced vital capacity (FVC), forced expiratory volume in 1 s (FEV(1)), FEV(1)/FVC ratio and peak expiratory flow (PEF). Maternal history of asthma and allergy was assessed at birth. The effect of breastfeeding on lung function was analysed using general linear models, adjusting for birth weight, sex, current height and weight, family social status cluster and maternal education.

RESULTS

Compared with those who were not breastfed, FVC was increased by 54.0 (SE 21.1) ml (p = 0.001), FEV(1) by 39.5 (20.1) ml(p = 0.05) and PEF by 180.8 (66.1) ml/s (p = 0.006) in children who were breastfed for at least 4 months. In models for FEV(1) and PEF that adjusted for FVC, the effect of breastfeeding was retained only for PEF (p = 0.04).

CONCLUSIONS

Breastfeeding for at least 4 months enhances lung volume in children. The effect on airflow appears to be mediated by lung volume changes. Future studies need to elucidate the mechanisms that drive this phenomenon.

Content of beta-casomorphins in milk of women with a history of allergy

The prevalence of food allergies increased over the past decade. Most symptoms of food allergy appear during the first 2 yr of life. The aim of this study was to determine the beta-casomorphin-5 and -7 (BCMs) in colostrum and milk of 12 breast-feeding women with a history and clinical manifestation of food allergy. The results were compared with the data obtained from a control group of healthy age-matched breast-feeding women. The level of BCM in women with food allergy was constant during lactation, whereas the highest level of opioid peptides was found in colostrums of healthy women with a subsequent rapid decrease in mature milk. These differences in BCMs profile between allergic and healthy breast-feeding women suggest that BCM content in the human milk may be an indicator of allergic conditions.

Antiinfective properties of human milk

The unfavorable effects of neonatal immunodeficiency are limited by some naturally occurring compensatory mechanisms, such as the introduction of protective and immunological components of human milk in the infant. Breast-feeding maintains the maternal-fetal immunological link after birth, may favor the transmission of immunocompetence from the mother to her infant, and is considered an important contributory factor to the neonatal immune defense system during a delicate and crucial period for immune development. Several studies have reported that breast-feeding, because of the antimicrobial activity against several viruses, bacteria, and protozoa, may reduce the incidence of infection in infants. The protection from infections may be ensured either passively by factors with antiinfective, hormonal, enzymatic, trophic, and bioactive activity present in breast milk, or through a modulator effect on the neonatal immune system exerted by cells, cytokines, and other immune agents in human milk.

Low breast milk TGF-beta2 is induced by Lactobacillus reuteri supplementation and associates with reduced risk of sensitization during infancy

The immunological composition of breast milk differs between mothers. The reasons for these differences and the consequences for the breast-fed infants are poorly understood. The aim of this study was to evaluate the effect of probiotic Lactobacillus reuteri supplementation on the immunological composition of breast milk in relation to sensitization and eczema in the babies. Total IgA, secretory IgA (SIgA), TGF-beta1, TGF-beta2, IL-10, TNF, soluble CD14 (sCD14), and Na/K ratios were analyzed in colostrum and mature milk obtained from women treated with L. reuteri (n = 54) or placebo (n = 55) from gestational week 36 until delivery. Bacteriological analyses of L. reuteri were performed in faecal samples of the mothers. The infants were followed prospectively for 2 yr regarding development of eczema and sensitization as defined by a positive skin prick test and/or circulating allergen-specific IgE antibodies at 6, 12, and 24 months of age. Supplementation of L. reuteri during pregnancy was associated with low levels of TGF-beta2 and slightly increased levels of IL-10 in colostrum. For TGF-beta2, this association was most pronounced in mothers with detectable L. reuteri in faeces. Infants receiving breast milk with low levels of TGF-beta2 were less likely to become sensitized during their first 2 yr of life. A similar trend was observed for development of IgE-associated eczema. The levels of total IgA, SIgA, TGF-beta1, TNF, sCD14, and Na/K ratios in breast milk were not affected by the intake of L. reuteri. None of these parameters correlated with sensitization or development of eczema in the infant, except for high Na/K ratios that associated with increased risk of sensitization. Supplementation with L. reuteri during late pregnancy reduces breast milk levels of TGF-beta2, and low levels of this cytokine are associated with less sensitization and possibly less IgE-associated eczema in breast-fed infants.

IgE against food and respiratory allergens in healthy and allergic mothers and their children

IgE against mixtures of common food or respiratory allergens were determined by ELISA in healthy (n = 38) and allergic (n = 62) mothers and their children. Significantly higher level of IgE against respiratory allergens was found in sera of allergic mothers and in cord blood of their children. No correlation between antibody level in maternal and newborn's sera was found; this argues against the transfer of IgE from mother to fetus and points rather to offspring's intrauterine sensitization. Specific IgE level in cord blood was higher in children who developed later allergy than in children who did not. Specific IgE level in colostrum was low both in healthy and allergic mothers; there was no correlation between high concentration of IgE against respiratory allergens in sera of allergic mothers and their colostrum, which does not support the idea of IgE transport from blood to mammary gland. Only slightly increased colostral IgE was detected in allergic mothers whose children manifested allergy later. Allergy of the mother and high level of anti-allergen IgE in her serum and in cord blood are the main predictive factors of future occurrence of allergy in the offspring. A combination of several predictive factors could have higher prognostic value.

The immunological components of human milk

Breast-feeding is generally accepted as the optimal method of feeding infants. However, we have yet to fully understand the complex mixture of bioactive compounds contained in human milk. Epidemiological studies have indicated that breast-feeding is associated with health benefits in the infant for many immune-related conditions. Breast milk contains various antimicrobial substances, factors that promote immune development, constituents that promote tolerance/priming of the infant immune system, as well as anti-inflammatory components. This chapter identifies and discusses the immunological compounds in human milk and the available evidence for their effect on the immune system of the infant. Current feeding regimens recommended for infants are based primarily on the current understanding of the nutritional requirements of the neonate, but perhaps will be modified to reflect the consequences on immune function both immediate and later in life.

Effect of breast milk of healthy and allergic mothers on in vitro stimulation of cord blood lymphocytes

Maternal milk has beneficial effects on the development and function of the newborn's immune system. Whether the milk of allergic mother has the same effects as the milk of healthy mothers is not yet quite clear. To contribute to the characterization of its immunomodulatory action, we tested the effect of milk of healthy and allergic mothers on the proliferation and immunoglobulin formation in cultures of cord blood mononuclear leucocytes (CBML) of newborns of healthy and allergic mothers. CBML proliferation was tested by (3)H-thymidine incorporation, IgM, IgG and IgA production by reverse ELISPOT. CBML response was examined in unstimulated cultures and after stimulation with polyclonal activators in the presence or absence of colostrum or milk. The cells of children of allergic mothers have a significantly higher proliferative activity than those of children of healthy mothers. Maternal colostrum/milk in high doses markedly suppresses cell proliferation after stimulation with polyclonal activators, whereas lower milk doses in the cultures have no such effect and exert a rather stimulatory action. Immunoglobulin production by cord blood lymphocytes is also different in the two groups of children. Low basal immunoglobulin formation is increased after stimulation with a strong polyclonal activator of B cells--Bacillus firmus, CBML of children of allergic mothers produce more IgA than those of children of healthy mothers. The stimulated production of all immunoglobulin classes in cells of children of healthy mothers is still enhanced by colostrum/milk. Children of allergic mothers show a markedly increased production of only IgM and IgA. The effect of healthy and allergic colostrum and milk on cell proliferation and immunoglobulin production is similar. The lymphocytes of children of allergic mothers differ from the lymphocytes of children of healthy mothers in their proliferative activity and the ability to form immunoglobulin already at birth.

Immunomodulatory constituents of human milk change in response to infant bronchiolitis

Although epidemiological evidence is generally supportive of a causal association between respiratory syncytial virus (RSV) bronchiolitis during infancy and the development of persistent wheeze/asthma, if not allergy, the mechanism by which this occurs and an explanation for why all children do not succumb remains to be elucidated. Breast feeding has been found to confer a protective effect against respiratory infections such as RSV bronchiolitis and allergy; however, again there is little direct evidence and no clear mechanism. In this study, we examined whether human milk immunomodulatory factors (cells, cytokines) change in response to clinically diagnosed, severe bronchiolitis in the recipient breast-fed infant. We examined milk from 36 breast feeding mothers of infants hospitalized with bronchiolitis and compared them with milk from 63 mothers of postpartum age-matched healthy controls. Milks from mothers of infants hospitalized with bronchiolitis had significantly greater numbers of viable cells when compared with the milks obtained from mothers of healthy infants (1.3 +/- 0.4 vs. 0.3 +/- 0.03 x 10(6) cells/ml, mean +/- s.e.m.; p < or = 0.001). Further, the cells obtained from the mothers of infants hospitalized with bronchiolitis were found to produce a skewed cytokine profile ex vivo in response to stimulation by live RSV but not when cultured with a non-specific mitogen (concanavalin A). This study provides preliminary evidence for an immunological link between mothers and their breast-fed infants during severe respiratory infections as well as a possible contributing factor to the development of persistent wheeze in these infants.

Maternal influence in the transmission of asthma susceptibility

Asthma is one of the most common chronic diseases in children, with increasing morbidity and mortality. A genetic predisposition and exposure to allergens have been implicated as major risk factors for the development of asthma. However, increasing evidence indicates that the mother plays a crucial role in mediating the development of fetal-infant immune responses to inhaled allergens. The exact nature and mechanism of this maternal influence and how it might be associated with the development of allergic sensitization and asthma are not clear. Under normal conditions, the maternal environment during pregnancy promotes an initial Th2 skewed immune response in the offspring which transitions to a nonallergic Th1 type response after birth. However, the allergic mother's influence may delay the normal transition to a nonallergic immune response to inhaled allergens in her children, thus increasing the risk for the development of allergic sensitization and/or asthma. Understanding the underlying mechanisms by which the maternal immune environment can influence the development of the fetal-infant immune response to inhaled allergens may lead to identifying new targets for the prevention of allergic sensitization and asthma.

Interleukin-10 and -12 in human milk at 3 stages of lactation: a longitudinal study

This study was undertaken to analyze postpartum changes in concentrations of interleukin (IL)-10 and IL-12 through the 3 stages of lactation. A total of 87 human milk samples were collected from 29 healthy mothers during the colostrum (0-3 days), early milk (14-17 days), and mature milk (44-47 days) phases. Enzyme-linked immunosorbent assay tests were performed on the milk samples. IL-10 was detected in 7 and IL-12 in 4 of the colostrum samples. In the transitional milk samples, IL-10 was present in 4 and IL-12 in 2; however, both of these cytokines became undetectable in mature milk samples. The decrease in concentrations of IL-10 and IL-12 was statistically significant during the postpartum period (P=.001 and P=.024, respectively). IL-10 levels in the colostrum samples were higher than in the transitional samples (P=.018, with use of the post hoc test). No statistically significant differences between IL-12 levels were noted in the colostrum samples and the transitional samples (P=.068, with use of the post hoc test). A negative correlation was observed between concentrations of IL-10 in colostrum and the total number of pregnancies (R=-.401; P=.031). The findings of the present study suggest that mean concentrations of IL-10 and IL-12 are decreased in human milk as lactation continues through its 3 phases.