Enhancement of immune maturation in suckling rats by leptin and adiponectin supplementation

Leptin and adiponectin, adipokines present in breast milk, have shown immunomodulatory properties. The current study aimed to ascertain whether a nutritional supplementation with leptin or adiponectin in neonatal rats was able to infuence the maturation of the systemic immune response in early life. To achieve this, suckling Wistar rats were supplemented with either leptin (0.7μg/kg/day) or adiponectin (35μg/kg/day) during the whole suckling period. Plasmatic immunoglobulins were quantifed, and spleen lymphocyte composition and their ability to proliferate and release cytokines were evaluated during (day 14) and at the end (day 21) of the suckling period. Rats fed with either adipokine showed higher plasma IgM and IgG1 concentrations and adiponectin supplementation also increased IgG2a at both studied days (P<0.05). With regard to the lymphocyte composition, both adipokine supplementations increased T cell proportion and both CD4+ and CD8+ T cell subsets after two weeks of supplementation (P<0.05). Moreover, only leptin administration increased NK and NKT cell proportions at the end of the suckling period. Finally, both adipokines infuenced the cytokine secretion pattern by splenocytes. In conclusion, these results suggest that leptin and adiponectin play a role in the maturation of the systemic immune response during the suckling period

Leptin and adiponectin supplementation modifies mesenteric lymph node lymphocyte composition and functionality in suckling rats

At birth, when immune responses are insufficient, there begins the development of the defence capability against pathogens. Leptin and adiponectin, adipokines that are present in breast milk, have been shown to play a role in the regulation of immune responses. We report here, for the first time, the influence of in vivo adipokine supplementation on the intestinal immune system in early life. Suckling Wistar rats were daily supplemented with leptin (0·7 μg/kg per d, n 36) or adiponectin (35 μg/kg per d, n 36) during the suckling period. The lymphocyte composition,proliferation and cytokine secretion from mesenteric lymph node lymphocytes (on days 14 and 21), as well as intestinal IgA and IgM concentration (day 21), were evaluated. At day 14, leptin supplementation significantly increased the TCRαβ+ cell proportion in mesenteric lymph nodes, in particular owing to an increase in the TCRαβ+ CD8+ cell population. Moreover, the leptin or adiponectin supplementation promoted the early development CD8+ cells, with adiponectin being the only adipokine capable of enhancing the lymphoproliferative ability at the end of the suckling period. Although leptin decreased intestinal IgA concentration, it had a trophic effect on the intestine in early life. Supplementation of both adipokines modulated the cytokine profile during (day 14) and at the end (day 21) of the suckling period. These results suggest that leptin and adiponectin during suckling play a role in the development of mucosal immunity in early life

Rat Milk and Plasma Immunological Profile throughout Lactation

The composition of bioactive factors with immune activity in human breast milk is widely studied. However, the knowledge on rat milk immune factors during the whole lactation period is still scarce. This study aimed to analyze rat breast milk's immunoglobulin (Ig) content and some critical adipokines and growth factors throughout the lactation period, and to assess relationships with corresponding plasma levels. During lactation, milk concentration of the transforming growth factor (TGF)-β2 and -β3 showed a punctual increase in the first week, whereas adiponectin and leptin remained stable. In the second period of lactation (d14-21), despite the increase in the milk epidermal growth factor (EGF), a decrease in fibroblast growth factor 21 (FGF21) was detected at day 21. Milk IgA concentration had a progressive increase during lactation, while no significant changes were found in IgM and IgG. Regarding plasma levels, a decrease in all studied adipokines was observed in the second period of lactation, with the exception of IgA and TGF-β1, which reached their highest values at the end of the study. A positive correlation in IgM, IgG, and adipokine concentration was detected between milk and plasma compartments. In summary, the changes in the pattern of these bioactive compounds in rat milk and plasma and their relationships during lactation are established

Modulation of the Systemic Immune Response in Suckling Rats by Breast Milk TGF-β2, EGF and FGF21 Supplementation

Breast milk is a rich fluid containing bioactive compounds such as specific growth factors (GF) that contribute to maturation of the immune system in early life. The aim of this study was to determine whether transforming growth factor- 2 (TGF- 2), epidermal growth factor (EGF) and fibroblast growth factor 21 (FGF21), compounds present in breast milk, could promote systemic immune maturation. For this purpose, newborn Wistar rats were daily supplemented with these GF by oral gavage during the suckling period (21 days of life). At day 14 and 21 of life, plasma for immunoglobulin (Ig) quantification was obtained and spleen lymphocytes were isolated, immunophenotyped and cultured to evaluate their ability to proliferate and release cytokines. The main result was obtained at day 14, when supplementation with EGF increased B cell proportion to reach levels observed at day 21. At the end of the suckling period, all GF increased the plasma levels of IgG1 and IgG2a isotypes, FGF21 balanced the Th1/Th2 cytokine response and both EGF and FGF21 modified splenic lymphocyte composition. These results suggested that the studied milk bioactive factors, mainly EGF and FGF21, may have modulatory roles in the systemic immune responses in early life, although their physiological roles remain to be established

Leptin and adiponectin variations in rat’s milk and plasma throughout the lactation period

Podeu consultar el III Workshop anual INSA-UB complet a: http://hdl.handle.net/2445/118993Sessió 1. Pòster núm. 1

Nutrition during pregnancy and lactation: New evidence for the vertical transmission of extra virgin olive oil phenolic compounds in rats

Maternal breast milk provides the newborn with passive immunity and stimulates the maturation of the infant immune system. The aim of the present study was to evaluate the vertical transmission of phenolic compounds and their metabolites to offspring in rats fed with extra virgin olive oil (EVOO) during pregnancy and lactation. For this purpose, plasma and lactic serum from dams and plasma from offspring were analyzed by LC-ESI-LTQ-Orbitrap-MS. Both enzymatic and microbial metabolites of hydroxytyrosol and tyrosol were detected in dam plasma and lactic serum. In addition, significant levels of phenolic compounds and their metabolites were found in offspring plasma. The concentration and number of hydroxytyrosol derivatives was higher than those of tyrosol and the microbial metabolites were found in the highest concentration. The observed vertical transmission of EVOO phenolic compounds, whose health benefits are widely reported, provides further support for the importance of the maternal diet during pregnancy and lactation

A Preterm Rat Model for Immunonutritional Studies

Neonates are born with an immature immune system, which develops during the first stages of life. This early immaturity is more acute in preterm newborns. The aim of the present study was to set up a preterm rat model, in which representative biomarkers of innate and adaptive immunity maturation that could be promoted by certain dietary interventions are established. Throughout the study, the body weight was registered. To evaluate the functionality of the intestinal epithelial barrier, in vivo permeability to dextrans was measured and a histomorphometric study was performed. Furthermore, the blood cell count, phagocytic activity of blood leukocytes and plasmatic immunoglobulins (Ig) were determined. Preterm rats showed lower erythrocyte and platelet concentration but a higher count of leukocytes than the term rats. Although there were no changes in the granulocytes' ability to phagocytize, preterm monocytes had lower phagocytic activity. Moreover, lower plasma IgG and IgM concentrations were detected in preterm rats compared to full-term rats, without affecting IgA. Finally, the intestinal study revealed lower permeability in preterm rats and reduced goblet cell size. Here, we characterized a premature rat model, with differential immune system biomarkers, as a useful tool for immunonutritional studies aimed at boosting the development of the immune system

Leptin and EGF Supplementation Enhance the Immune System Maturation in Preterm Suckling Rats

In preterm newborns the immaturity of the immune system is remarkable, with reduced innate and adaptive immune responses. Many bioactive compounds in breast milk, such as growth factors and adipokines, contribute to the immune system's maturation in early life. However, studies on the immunoregulatory activity in preterm neonates are practically nonexistent. The aim of the present study was to determine whether a nutritional supplementation in early life with leptin or epidermal growth factor (EGF) was able to promote the maturation of the systemic and intestinal immune system in preterm conditions. For this purpose, premature rats were daily supplemented by oral gavage with leptin or EGF. Term and Preterm groups receiving vehicle were used as controls. Preterm rats showed deficiencies compared to full-term ones, such as lower body weights, erythrocyte counts, plasma IgG and IgM concentrations and B cell percentages, and higher values of Th and Tc TCRαβ+ cells in mesenteric lymph nodes, and intestinal permeability, among others. However, leptin and EGF supplementation were able to revert some of these deficiencies and to improve the premature immune system's development. These results suggest that leptin and EGF are involved in enhancing the maturation of the systemic and intestinal immune system in preterm conditions

Influence of Leptin and Adiponectin Supplementation on Intraepithelial Lymphocyte and Microbiota Composition in Suckling Rats

Dietary components in early life play a role in both microbiota and intestinal immune system maturation in mammalian species. Adipokines, as endogenously produced hormones from breast milk, may have an impact on this process. The aim of the present study was to establish the influence of leptin and adiponectin supplementation during suckling on the intraepithelial lymphocyte composition, intestinal barrier function, intestinal gene expression, and gut microbiota in rat. For this purpose, newborn Wistar rats were supplemented daily with leptin, adiponectin, or whey protein concentrate during the first 21 days of life. Lymphocyte composition was established by immunofluorescence staining and flow cytometry analysis; intestinal gene expression by real-time PCR and cecal microbiota were analyzed through 16S rRNA gene sequencing. Although leptin and adiponectin were able to increase the Tc TCRαβ+ and NKT cell proportion, they decreased the NK cell percentage in IEL. Moreover, adipokine supplementation differentially modified CD8+ IEL. While the supplementation of leptin increased the proportion of CD8αα+ IEL (associated to a more intestinal phenotype), adiponectin enhanced that of CD8αβ+ (related to a peripheral phenotype). Furthermore, both adipokines enhanced the gene expression of TNF-α, MUC-2, and MUC-3, and decreased that of FcRn. In addition, the adipokine supplementations decreased the abundance of the Proteobacteria phylum and the presence of Blautia. Moreover, leptin-supplemented animals had lower relative abundance of Sutterella and a higher proportion of Clostridium genus, among others. However, supplementation with adiponectin resulted in lower abundance of the Roseburia genus and a higher proportion of the Enterococcus genus. In conclusion, the supplementation with leptin and adiponectin throughout the suckling period had an impact on both the IEL composition and the gut microbiota pattern, suggesting a modulatory role of these adipokines on the development of intestinal functionality

Impact of maternal Bifidobacterium breve M-16V and scGOS/lcFOS supplementation during pregnancy and lactation on the maternal immune system and milk composition

IntroductionMaternal synbiotic supplementation during pregnancy and lactation can significantly influence the immune system. Prebiotics and probiotics have a positive impact on the immune system by preventing or ameliorating among others intestinal disorders. This study focused on the immunomodulatory effects of B. breve M-16V and short chain galacto-oligosaccharides (scGOS)/long chain fructo-oligosachairdes (lcFOS), including systemic and mucosal compartments and milk composition. MethodsLewis rats were orally administered with the synbiotic or vehicle during pregnancy (21 days) and lactation (21 days). At the weaning day, small intestine (SI), mammary gland (MG), adipose tissue, milk, mesenteric lymph nodes (MLN), salivary gland (SG), feces and cecal content were collected from the mothers.ResultsThe immunoglobulinome profile showed increased IgG2c in plasma and milk, as well as elevated sIgA in feces at weaning. The supplementation improved lipid metabolism through enhanced brown adipose tissue activity and reinforced the intestinal barrier by increasing the expression of Muc3, Cldn4, and Ocln. The higher production of short chain fatty acids in the cecum and increased Bifidobacterium counts suggest a potential positive impact on the gastrointestinal tract. DiscussionThese findings indicate that maternal synbiotic supplementation during gestation and lactation improves their immunological status and improved milk composition