Escherichia Coli Specific Secretory IgA and Cytokines in Human Milk from Mothers of Different Ethnic Groups Resident in Northern Italy

Abstract

Breast milk supplies many bioactive components. Neonates protection from pathogenic bacteria is mainly attributable to secretory IgA antibodies present in human milk in an amount depending on previous antigenic exposure. To bring new details into the field of immunological memory in secretory immunity, we evaluated the production of s-IgA specific for E. coli (E. coli s-IgA), and of proinflammatory (IL-6 and IL-8) or anti-inflammatory (IL-IO) cytokines in the milk of mothers of different ethnic groups exposed in the past to poor conditions, but nowadays living in Italy in adequate conditions. Mothers from Italy, Africa, Asia and Eastern European Countries were included in the study. Anti-E. coli s-IgA, IL-6, IL-8 and IL-IO were determined by ELISA. Breast milk of all the foreign mothers presented higher levels of E. coli s-IgA than Italians, and for Asian and African mothers were significative (p=0.031 and p=0.015, respectively). Milk from women of Eastern European Countries revealed the highest IL-8 levels (p=0.026), while milk from Asian women presented the greatest concentration of IL-6 (p=0.04); however, the Africans reported the lowest concentrations of IL-IO (p=0.045). Since all the mothers had been living in Italy for some time, we believe that the presence of high levels of E.coli s-IgA, supported by high levels of pro-inflammatory cytokine, is part of a persisting immunological secretory memory.Breast milk supplies newborns not only with nutrients, but also with very important bioactive components that modulate the immune response and ameliorate the development of the gastrointestinal tract. Breastfed infants develop less infections than bottle-fed infants and this is related to the different agents with antimicrobial, anti-inflammatory and immunomodulating action, unique to human milk (1-3). The protection of the newborn's intestinal and respiratory tract from pathogenic bacteria is also attributable to antibodies present in milk (4-5).In the so called entero-mammaric link, once antigens are presented to the mother's gut, the responding B cells switch to the production of IgA that, leaving the Peyer's patches, migrate to the mammary glands and passing through, appear in milk, stabilized by the secretory component (4).In human milk, secretory IgA (s-IgA) is the predominant isotype and acts as first line defence in mucosal areas of the infant (5-6) against the

Maternal country of birth and previous pregnancies are associated with breast milk characteristics

“…The higher levels of IL‐6 and IL‐8 in breast milk observed here are consistent with a previous report on immigrant mothers living in Italy (40). The higher IL‐6 and IL‐8 levels from immigrant mothers who grew up in a developing country could lead to an over‐stimulation of the immune system among offspring born in Sweden, with its lower level of exposure to micro‐organisms.…”

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

“…As stated above, several factors have been suggested to affect the immune composition of human milk, including the health status of the mother-infant dyad (18, 20, 79–81). Increased exposure to pathogens, as those occurring in clinical and subclinical mastitis (82, 83) and during infectious disease of the breastfed infant (84–86), might relate to increased pro-inflammatory factors in human milk.…”

“…Therefore, it is reasonable to assume that the concentrations of these substances in milk produced by healthy women may depend on an individual’s own life circumstances. Previous studies focused on the immunological composition of human milk have assessed a narrow panel of immune factors, have recruited women from a single location, and/or have included a relatively small sample size (20–26). In this context, the objective of this work was the assessment of a wide spectrum of immunological compounds, including innate immunity factors, acquired immunity factors, chemokines, growth factors, and Ig, in milk produced by healthy women of different ethnicities, living in high-, middle-, and low-income countries and, therefore, including very different geographical, dietary, socioeconomic, and environmental settings.…”

Impact of Porcine Orexin a on Glucagon Plasma Concentrations in Pigs

“…Neuropeptides control the huge number of incoming and outgoing signals, which take place in the hypothalamus, since they are basically the carriers of these signal data (30)(31)(32)(33). The sense of appetite is probably due partly to Orexin A, and partly to the existence of a whole group of neuropeptides acting together in the hypothalamus and the gastrointestinal tract (1-2, 34).…”