Human Milk Oligosaccharide 2′-Fucosyllactose Improves Innate and Adaptive Immunity in an Influenza-Specific Murine Vaccination Model

Abstract

BackgroundHuman milk is uniquely suited to provide optimal nutrition and immune protection to infants. Human milk oligosaccharides are structural complex and diverse consisting of short chain and long chain oligosaccharides typically present in a 9:1 ratio. 2′-Fucosyllactose (2′FL) is one of the most prominent short chain oligosaccharides and is associated with anti-infective capacity of human milk.AimTo determine the effect of 2′FL on vaccination responsiveness (both innate and adaptive) in a murine influenza vaccination model and elucidate mechanisms involved.MethodsA dose range of 0.25–5% (w/w) dietary 2′FL was provided to 6-week-old female C57Bl/6JOlaHsd mice 2 weeks prior primary and booster vaccination until the end of the experiment. Intradermal (i.d.) challenge was performed to measure the vaccine-specific delayed-type hypersensitivity (DTH). Antigen-specific antibody levels in serum as well as immune cell populations within several organs were evaluated using ELISA and flow cytometry, respectively. In an ex vivo restimulation assay, spleen cells were cocultured with influenza-loaded bone marrow-derived dendritic cells (BMDCs) to study the effects of 2′FL on vaccine-specific CD4+ and CD8+ T-cell proliferation and cytokine secretions. Furthermore, the direct immune regulatory effects of 2′FL were confirmed using in vitro BMDCs T-cell cocultures.ResultsDietary 2′FL significantly (p < 0.05) enhanced vaccine specific DTH responses accompanied by increased serum levels of vaccine-specific immunoglobulin (Ig) G1 and IgG2a in a dose-dependent manner. Consistently, increased activation marker (CD27) expression on splenic B-cells was detected in mice receiving 2′FL as compared to control mice. Moreover, proliferation of vaccine-specific CD4+ and CD8+ T-cells, as well as interferon-γ production after ex vivo restimulation were significantly increased in spleen cells of mice receiving 2′FL as compared to control mice, which were in line with changes detected within dendritic cell populations. Finally, we confirmed a direct effect of 2′FL on the maturation status and antigen presenting capacity of BMDCs.ConclusionDietary intervention with 2′FL improves both humoral and cellular immune responses to vaccination in mice, which might be attributed in part to the direct effects of 2′FL on immune cell differentiation.

Human milk oligosaccharides promote immune tolerance via direct interactions with human dendritic cells

“…Dietary intervention with HMOS in vivo has shown to significantly reduce diabetes incidence, possibly through reducing the induction of diabetogenic cytokines such as IL‐17 and IFN‐γ in a NOD‐mice model . On the other hand, in line with known effects of scGOS/lcFOS, we have recently demonstrated that specific HMOS, namely 2’FL, can effectively enhance vaccine‐specific immune responses by inducing Th1 type of immunity including IFN‐γ responses within an influenza vaccination mouse model . In this regard, HMOS induced an anti‐inflammatory cytokine profile of DCs that promotes IL‐10 producing Tregs generation in a steady state, suggesting regulatory function of HMOS in vivo.…”

Human Milk Oligosaccharides: Health Benefits, Potential Applications in Infant Formulas, and Pharmacology

“…Administration of 2 FL in mice improved the humoral and cellular immune response to vaccination. It is thought that this is a direct 2 FL effect on the differentiation of immune cells [62].…”

The Importance of Vaccinating Children and Pregnant Women against Influenza Virus Infection

“…Furthermore, cells are transferred to the infant via breastfeeding, which could play a role in shaping the neonatal and infant microbiome [192]. Of note, studies have shown that HMOs fed to mice could be transferred into circulation, had no observable adverse health effects and improved the immune response to influenza virus infection [193][194][195]. In adult humans, HMO ingestion was well tolerated in a two-week oral administration regiment [196].…”