Distribution of IgG subclasses in human colostrum and milk

Comparative Detection of Immunoglobulin Isotypes and Subclasses against Toxoplasma gondii Soluble Antigen in Serum and Colostrum Samples from Puerperal Women

Background: Toxoplasma gondii is an obligate intracellular parasite that can infect several species, including humans, and can cause severe damage to the fetus when the infection occurs during pregnancy. The environment and/or food contamination are critical to spreading the infection. Human milk is rich in nutrients and bioactive elements that provide growth and development of the immune system of the newborn. All isotypes of immunoglobulins are present in human colostrum and they are produced from systemic or local sources. Breastfeeding protects the infant against various pathogens, but there is no conclusive study to detect IgG subclasses in colostrum against T. gondii. Therefore, the aim of this study was to detect and evaluate the presence of antibody isotypes against T. gondii in paired samples of serum and colostrum. Methods: The study included 283 puerperal patients. ELISA (Enzyme-Linked Immunosorbent Assay) for detection of anti-T. gondii-specific IgM, IgA, and IgG isotypes and IgG1, IgG3, and IgG4 subclasses were conducted on paired samples of serum and colostrum. Results: It was found that 45.9%, 6.0%, and 2.1% of serum samples and 45.2%, 7.1%, and 2.1% of colostrum samples were positive for IgG, IgM, and IgA, respectively. Specific IgG1, IgG3, and IgG4 were positive, respectively, in 98.5%, 54.6%, and 44.6% of serum samples, in contrast with 56.9%, 78.5%, and 34.6% of colostrum samples. Thus, the predominant reactivity of IgG subclasses against T. gondii was IgG1 in serum and IgG3 in colostrum. The higher percentage of positive samples and higher levels of anti-T. gondii IgG3 antibodies were observed in colostrum, when compared to serum samples, suggesting a local production of this subclass. IgG3 and IgG1 subclasses presented different percentages of positivity in serum and colostrum. Only the IgG1 subclass showed a significant correlation between the levels of anti-T. gondii in serum and colostrum, suggesting that IgG1 in breast milk comes from a systemic source. IgG4 showed a similar percentage of positivity in both sample types, but no significant correlation was observed between their levels. Conclusion: Colostrum presents representative levels of IgM, IgA, IgG1, IgG3, and IgG4 antibodies specific to T. gondii. The detection of these antibodies presents the potential for diagnostic application of colostrum samples to better identify the diagnostic status of T. gondii infection, especially during the acute phase. In addition, breastfeeding can also be a possible source of protective antibodies for the newborn against toxoplasmosis, an anthropozoonosis maintained by environmental infection, which interferes in the public health of many countries.

Maternal immune protection against infectious diseases

The maternal immune system protects developing offspring against pathogens before birth via transplacental transfer and after birth through secreted milk. This transferred maternal immunity influences each generation's susceptibility to infections and responsiveness to immunization. Thus, boosting immunity in the maternal-neonatal dyad is a potentially valuable public health strategy. Additionally, at critical times during fetal and postnatal development, environmental factors and immune stimuli influence immune development. These "windows of opportunity" offer a chance to identify both risk and protective factors that promote long-term health and limit disease. Here, we review pre- and postpartum maternal immune factors that protect against infectious agents in offspring and how they may shape the infant's immune landscape over time. Additionally, we discuss the influence of maternal immunity on the responsiveness to immunization in early life. Lastly, when maternal factors are insufficient to prevent neonatal infectious diseases, we discuss pre- and postnatal therapeutic strategies for the maternal-neonatal dyad.

The Breast Milk Immunoglobulinome

Breast milk components contribute to the infant’s immune development and protection, and among other immune factors, immunoglobulins (Igs) are the most studied. The presence of IgA in milk has been known for a long time; however, less information is available about the presence of other Igs such as IgM, IgG, and their subtypes (IgG1, IgG2, IgG3, and IgG4) or even IgE or IgD. The total Ig concentration and profile will change during the course of lactation; however, there is a great variability among studies due to several variables that limit establishing a clear pattern. In this context, the aim of this review was firstly to shed light on the Ig concentration in breast milk based on scientific evidence and secondly to study the main factors contributing to such variability. A search strategy provided only 75 studies with the prespecified eligibility criteria. The concentrations and proportions found have been established based on the intrinsic factors of the study—such as the sampling time and quantification technique—as well as participant-dependent factors, such as lifestyle and environment. All these factors contribute to the variability of the immunoglobulinome described in the literature and should be carefully addressed for further well-designed studies and data interpretation.

Associations of Breast Milk Microbiota, Immune Factors, and Fatty Acids in the Rat Mother-Offspring Pair

The present study aimed to analyze the rat breast milk profile of fatty acids (FA), immunoglobulins (Ig), microbiota, and their relationship, and to further assess their associations in the mother–offspring pair. Dams were monitored during the three weeks of gestation, allowed to deliver at term, and followed during two weeks of lactation. At the end of the study, milk was obtained from the dams for the analysis of fatty acids, microbiota composition, immunoglobulins, and cytokines. Moreover, the cecal content and plasma were obtained from both the dams and pups to study the cecal microbiota composition and the plasmatic levels of fatty acids, immunoglobulins, and cytokines. Rat breast milk lipid composition was ~65% saturated FA, ~15% monounsaturated FA, and ~20% polyunsaturated FA. Moreover, the proportions of IgM, IgG, and IgA were ~2%, ~88%, and ~10%, respectively. Breast milk was dominated by members of Proteobacteria, Firmicutes, and Bacteroidetes phyla. In addition, forty genera were shared between the milk and cecal content of dams and pups. The correlations performed between variables showed, for example, that all IgGs subtypes correlated between the three compartments, evidencing their association in the mother-milk-pup line. We established the profile of FA, Ig, and the microbiota composition of rat breast milk. Several correlations in these variables evidenced their association through the mother-milk-pup line. Therefore, it would be interesting to perform dietary interventions during pregnancy and/or lactation that influence the quality of breast milk and have an impact on the offspring.

Antibody Profile of Colostrum and the Effect of Processing in Human Milk Banks: Implications in Immunoregulatory Properties

BACKGROUND

When feeding preterm infants, donor milk is preferred if the mother's own milk is unavailable. Pasteurization may have detrimental effects on bioactivity, but more information is needed about its effects on the immunological compounds. Research aim: This work has two main aims: evaluate the antibody profile of colostrum and study the quantitative variations in the antibodies' level and specific reactivity after undergoing Holder pasteurization. The authors focused on immunoregulatory components of colostrum (antidietary antibodies and TGF-β2) in the neonatal gut.

METHODS

This is a descriptive cross-sectional study of a convenience sample of 67 donated colostrum samples at different days after delivery, both raw and pasteurized. Antibody profiles were analyzed at different times during breastfeeding, and total and specific antibodies (IgM, IgA, and IgG subclasses) were compared with tetanus toxoid and ovalbumin using enzyme-linked immunosorbent assay. The processing effect on total and specific antibodies, as well as TGF-β2, was evaluated by paired analyses.

RESULTS

No variations in immunological compounds were observed throughout the colostrum stage. The TGF-β2, antibodies' concentrations, and antibodies' specific reactivity after pasteurization did not vary significantly as days of lactation varied. Changes in antibody levels were dependent on isotype and IgG subclass, and IgG4 showed remarkable resistance to heating. Moreover, the effect of the pasteurization on specific reactivity was antigen dependent.

CONCLUSION

The supply of relevant immunological components is stable throughout the colostrum stage. The effects of pasteurization on antibodies depend on isotype, subclass, and specificity. This information is relevant to improving the immunological quality of colostrum, especially for preterm newborns.

Anti-K1 (Kell) Antibody Expressed in Maternal Breastmilk: A Case Report of a Neonate with Multiple Intrauterine Transfusions and Postnatal Exposure to Kell Antibody in Maternal Breastmilk

Hemolytic disease of the fetus and newborn is a common consideration in newborn medicine, especially among the jaundiced. Maternal breastmilk provides numerous benefits to the infant, including nutrition and immunologic factors. Here, we present an infant who received three intrauterine transfusions for anemia secondary to anti-K1 (Kell), anti-C, and anti-e antibodies and whose maternal breastmilk tested positive for anti-Kell antibodies. The infant required another transfusion at 4 weeks of life for anemia. We review the pathophysiology of anti-Kell antibodies, the immunology of breast milk, and the intersection of these two topics.

The Mammary Gland in Mucosal and Regional Immunity

The mammary gland (MG) lacks a mucosa but is part of the mucosal immune system because of its role in passive mucosal immunity. The MG is not an inductive site for mucosal immunity. Rather, synthesis of immunoglobulin (Ig)A by plasma cells stimulated at distal inductive sites dominate in the milk of rodents, humans, and swine whereas IgG1 derived from serum predominates in ruminants. Despite the considerable biodiversity in the role of the MG, IgG passively transfers the maternal systemic immunological experience whereas IgA transfers the mucosal immunological experience. Although passive antibodies are protective, they and other lacteal constituents can be immunoregulatory. Immune protection of the MG largely depends on the innate immune system; the monocytes–macrophages group together with intraepithelial lymphocytes is dominant in the healthy gland. An increase in somatic cells (neutrophils) and various interleukins signal infection (mastitis) and a local immune response in the MG. The major role of the MG to mucosal immunity is the passive immunity supplied to the suckling neonate.

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.

Robust vaccine-elicited cellular immune responses in breast milk following systemic simian immunodeficiency virus DNA prime and live virus vector boost vaccination of lactating rhesus monkeys

Breast milk transmission of HIV remains an important mode of infant HIV acquisition. Enhancement of mucosal HIV-specific immune responses in milk of HIV-infected mothers through vaccination may reduce milk virus load or protect against virus transmission in the infant gastrointestinal tract. However, the ability of HIV/SIV strategies to induce virus-specific immune responses in milk has not been studied. In this study, five uninfected, hormone-induced lactating, Mamu A*01(+) female rhesus monkey were systemically primed and boosted with rDNA and the attenuated poxvirus vector, NYVAC, containing the SIVmac239 gag-pol and envelope genes. The monkeys were boosted a second time with a recombinant Adenovirus serotype 5 vector containing matching immunogens. The vaccine-elicited immunodominant epitope-specific CD8(+) T lymphocyte response in milk was of similar or greater magnitude than that in blood and the vaginal tract but higher than that in the colon. Furthermore, the vaccine-elicited SIV Gag-specific CD4(+) and CD8(+) T lymphocyte polyfunctional cytokine responses were more robust in milk than in blood after each virus vector boost. Finally, SIV envelope-specific IgG responses were detected in milk of all monkeys after vaccination, whereas an SIV envelope-specific IgA response was only detected in one vaccinated monkey. Importantly, only limited and transient increases in the proportion of activated or CCR5-expressing CD4(+) T lymphocytes in milk occurred after vaccination. Therefore, systemic DNA prime and virus vector boost of lactating rhesus monkeys elicits potent virus-specific cellular and humoral immune responses in milk and may warrant further investigation as a strategy to impede breast milk transmission of HIV.

Limited contribution of mucosal IgA to Simian immunodeficiency virus (SIV)-specific neutralizing antibody response and virus envelope evolution in breast milk of SIV-infected, lactating rhesus monkeys

Breast milk transmission of human immunodeficiency virus (HIV) remains an important mode of infant HIV acquisition. Interestingly, the majority of infants remain uninfected during prolonged virus exposure via breastfeeding, raising the possibility that immune components in milk prevent mucosal virus transmission. HIV-specific antibody responses are detectable in the milk of HIV-infected women and simian immunodeficiency virus (SIV)-infected monkeys; however, the role of these humoral responses in virus neutralization and local virus quasispecies evolution has not been characterized. In this study, four lactating rhesus monkeys were inoculated with SIVmac251 and monitored for SIV envelope-specific humoral responses and virus evolution in milk and plasma throughout infection. While the kinetics and breadth of the SIV-specific IgG and IgA responses in milk were similar to those in plasma, the magnitude of the milk responses was considerably lower than that of the plasma responses. Furthermore, a neutralizing antibody response against the inoculation virus was not detected in milk samples at 1 year after infection, despite a measurable autologous neutralizing antibody response in plasma samples obtained from three of four monkeys. Interestingly, while IgA is the predominant immunoglobulin in milk, the milk SIV envelope-specific IgA response was lower in magnitude and demonstrated more limited neutralizing capacity against a T-cell line-adapted SIV compared to those of the milk IgG response. Finally, amino acid mutations in the envelope gene product of SIV variants in milk and plasma samples occurred in similar numbers and at similar positions, indicating that the humoral immune pressure in milk does not drive distinct virus evolution in the breast milk compartment.

Mechanisms of Neonatal Mucosal Antibody Protection

Following an abrupt transition at birth from the sterile uterus to an environment with abundant commensal and pathogenic microbes, neonatal mammals are protected by maternal Abs at mucosal surfaces. We show in mice that different Ab isotypes work in distinct ways to protect the neonatal mucosal surface. Secretory IgA acts to limit penetration of commensal intestinal bacteria through the neonatal intestinal epithelium: an apparently primitive process that does not require diversification of the primary natural Ab repertoire. In contrast, neonatal protection against the exclusively luminal parasite Heligmosomoides polygyrus required IgG from primed females. This immune IgG could either be delivered directly in milk or retrotransported via neonatal Fc receptor from the neonatal serum into the intestinal lumen to exert its protective effect.

An overlap of breastfeeding during late pregnancy is associated with subsequent changes in colostrum composition and morbidity rates among Peruvian infants and their mothers

An overlap of breast-feeding and late pregnancy is associated with decreased intake of human milk and reduced infant growth. We evaluated the association of an overlap with macronutrient and immunological components of milk, infant urinary IgA, and infant and maternal morbidity. On d 2 and 1 mo postpartum, staff measured 24-h intake of breast milk and collected samples from 133 Peruvian women; 68 had breast-fed during the last trimester of pregnancy (BFP) and 65 had not breast-fed during pregnancy (NBFP). Data on maternal and infant anthropometry and health were collected for 1 mo. On d 2, lactose and lysozyme concentrations were higher, total lysozyme intake was higher and concentration and total intake of lactoferrin were lower in the BFP than the NBFP group (P < 0.05). The total 1-mo IgA intake was lower among BFP than NBFP infants (P = 0.01). Urinary IgA concentration was correlated with breast milk IgA concentration (r = 0.29; P = 0.01) but not with breast-feeding during pregnancy. An overlap was not associated with diarrhea but BFP infants were 5 times as likely to have a cough for at least 7 d than NBFP infants (P < 0.05). Reported mastitis was rare and occurred only in the NBFP group (P = 0.05). An overlap of breast-feeding and late pregnancy was associated with changes in milk composition, an increased frequency in symptoms of infant respiratory illness but decreased reported mastitis. Further in-depth studies are warranted to determine the cumulative effects associated with a breast-feeding/pregnancy overlap on infant and maternal outcomes.

Antibodies to Escherichia coli and Shigella flexneri in milk from undernourished mothers: studies on sodium dodecyl sulfate-polyacrylamide gel electrophoresis-separated antigens

Analysis of IgA, IgM, and IgG antibodies against Escherichia coli O6, its lipopolysaccharide (LPS), and Shigella flexneri were performed in the milk of moderately undernourished Guatemalan women receiving either a low or a high calorie supplement, using SDS-PAGE. As expected, the immunostaining analysis of milk antibodies showed that IgA was the predominant isotype in both groups. Concerning the other Igs, antibodies against O6 LPS were mainly of the IgM isotype, whereas IgG antibodies were more prominent than IgM against the bacterial whole cell preparations. Seven to nine distinct bands, ranging in molecular mass from 13.5 to 109 kD were selected for each antigen to compare the milk antibodies between the two groups of women. After a 20-wk supplementation period, the IgA and IgG antibodies to the E. coli, O6 LPS, and S. flexneri were not found negatively affected by a low calorie intake. A significantly lower immunostaining intensity was, however, obtained for the low calorie intake group regarding the IgM antibody activity against four high molecular mass bands of the E. coli whole cell preparation. A decreased immunostaining intensity was also found in the same group for IgM antibodies against two bands of E. coli O6 LPS when analyzing paired samples collected at d 0 and wk 20. No differences were found for IgM antibodies against any of the S. flexneri antigens. In conclusion, the results suggest that low calorie intake does not significantly affect the production of milk IgA antibodies to E. coli and S. flexneri antigens in these women. Still, IgM antibodies against certain proteins and LPS molecules of E. coli may be decreased. IgG antibodies, although also present in milk, seemed to be directed mainly against bacterial proteins and not to LPS.

Breast feeding: overview and breast milk immunology

The transfer of host defence capacity to the human offspring provides a remarkable model of passive transfer of immunity. In fact it may also provide an example of active immunization. The transfer of mucosal protection via breast feeding offers many additional advantages for the mother and infant. Through its contraceptive effects it increases the spacing between births, thus diminshing the infant mortality and the burden on the mother. It also enhances bonding between mother and child, it seems to increase the IQ and school result of the infant and might decrease the risk of certain malignancies and perhaps of juvenile diabetes. A fully breast-fed infant receives as much as 0.5-1 g of secretory immunoglobulin A (SIgA) antibodies daily, the predominant antibody of human milk. This can be compared to the production of some 2.5 g of SIgA per day for a 60 kg adult. These SIgA antibodies have been shown to protect against Vibrio cholerae, ETEC, Campylobacter, Shigella and Giardia. Furthermore, milk is rich in receptor analogues for certain epithelial structures which microbes need for attachment to host tissues as an initial step in infections. Thus the adherence of Haemophilus influenzae and pneumococci for example to retropharyngeal cells is efficiently inhibited by human milk. This may be one explanation for the fact that breast-fed babies have less otitis media than the non-breast-fed. Other milk factors like lysozyme and lactoferin may contribute to the host defence, but this has not yet been well defined. However, human milk also supports the well-being of the infant by being anti-inflammatory.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunoglobulin G subclasses in older persons with Down syndrome

IgG subclasses were measured in sera from 33 persons with Down syndrome (DS) (mean age 55 +/- 7 years) and 33 age- and sex-matched control individuals using a mouse monoclonal antibody based sandwich enzyme linked immunosorbent assay. Significantly higher levels of IgG1 and IgG3 and lower levels of IgG2 and IgG4 subclasses were found in the DS group compared to the control individuals. The higher levels of IgG1 and IgG3 subclasses found in DS persons were consistent with those seen in patients with autoimmune diseases and chronic viral infections; the lower levels of IgG2 and IgG4 subclasses were consistent with those seen in patients with recurrent infections. Our findings are similar to those reported in children with DS. We speculate that the subclass levels may have little or no relationship to the development of brain lesions typical of Alzheimer disease in older persons with DS. There were no significant differences between the levels of IgG subclasses of persons with DS showing signs of dementia of the Alzheimer type compared to those without such manifestations.

Preferential mammary storage and secretion of immunoglobulin gamma (IgG) subclasses in swine

Levels of three immunoglobulin gamma (IgG) subclasses, IgGA, IgGB and IgGC, were measured in sow sera, mammary glands, colostrum and milk samples by the single radial immunodiffusion. Serum IgGA and IgGB levels, but not IgGC, showed time dependent variations during gestation and lactation periods. The IgGA level started to decline at day 106 of gestation, reached its minimum at farrowing, and returned to the pre-gestation level 1-3 weeks after weaning. The serum IgGB level started to decrease at day 111 of gestation, reached its minimum at farrowing, and returned to the initial gestation level 1 week after farrowing. A notable decrease (P less than 0.1) in serum IgGC level was observed only on the day of farrowing. IgGA and IgGB were preferentially stored in mammary glands of full-term pregnant sows and secreted into colostrum after farrowing. In contrast, relatively small amounts of IgGC were stored in the mammary glands and secreted into colostrum. These data are interpreted as an indication that the preferential storage of IgGA and IgGB in the mammary gland of sows occurs at the time of significant decreases of these two IgG subclasses in the sera during late gestation and early lactation.

Ontogeny of immunity to oral microbiota in humans

This article reviews the ontogeny of immune systems in the human oral cavity that may influence the colonization, accumulation, or pathogenesis of oral microbiota. The prenatal development of cellular components associated with the secretory immune system reveals that the initial organization of tissue into Peyer's patches can first be detected immunohistologically at 11 weeks gestation. Epithelial cells positive for secretory component and immunocytes positive for IgM can be detected in salivary gland tissue by 19 to 20 weeks and continue to predominate during gestation. After birth, immunocytes containing IgA begin to dominate. Essentially, no IgA can be detected in saliva at birth. However, salivary IgA and IgM often appear soon thereafter, presumably in response to environmental antigenic and mitogenic challenges. Salivary IgA in young infants has molecular characteristics of secretory IgA and becomes the quantitatively predominate Ig in saliva. Both IgA subclasses are present in proportions characteristic of adult pure glandular salivas in many 1- to 2-month-old infants, although the appearance of IgA2 is delayed in some subjects. Many innate, antibody, and cellular immune components are found in maternal colostrum and breast milk. The antibacterial properties of these maternal factors are diverse and can exert multifaceted protective effects on the infant's alimentary tract. The infant apparently can mount mucosal immune responses quite early in life. For example, salivary antibody activity to organisms that originally colonize the gut (e.g., E. coli) or the oral cavity (e.g., S. mitis, S. salivarius) can be detected by 1 to 2 months of age. Most of this antibody activity has characteristics of secretory IgA, although some IgM antibody can also be initially detected. Salivary IgA1 and IgA2 antibody specificities to S. mitis and S. salivarius components increase qualitatively and quantitatively during the first few years of life. Salivary IgA antibody to components of streptococci that require hard surfaces for colonization (e.g., S. sanguis and mutans streptococci) generally appear after tooth eruption. The loss of placentally derived maternal IgG antibody specificities to these microbiota in the circulation is replaced by de novo synthesis, presumably as a result of the teething process. These IgG antibodies can enter the oral cavity in the gingival crevicular fluid and by the process of teething.(ABSTRACT TRUNCATED AT 400 WORDS)