# Induction of food allergen-specific neonatal tolerance through breast milk

> **NIH NIH R01** · BOSTON CHILDREN'S HOSPITAL · 2020 · $518,598

## Abstract

Project Summary
Food allergy is a growing public health concern. Regulatory T (Treg) cells play a pivotal role in tolerance to
food allergens, however, the effects of maternal immune responses on the induction of Treg cell-mediated
tolerance in offspring are poorly understood. We have recently found that maternal sensitization with allergen
(ovalbumin; OVA or peanut) prevented food allergic responses in murine offspring, as indicated by a decrease
in levels of food anaphylaxis, allergen-specific immunoglobulin (Ig) E, serum mouse mast cell proteinase 1,
and intestinal mast cell expansion in response to epicutaneous sensitization and oral challenge with the same
allergen. This protection was associated with an increase in levels of IgG and food allergen immune complexes
(IgG-IC) and transforming growth factor (TGF) β in breast milk. Neonatal Fc receptor (FcRn)-dependent
transfer of maternal IgG-IC via breast milk and IgG-IC presentation by neonatal CD11c+ dendritic cells (DCs)
promoted the differentiation of allergen-specific Treg cells in offspring. Breastfeeding by OVA-sensitized
mothers or maternal supplementation with IgG-IC induced neonatal tolerance. Consistently, human breast milk
collected from non-atopic mothers contained IgG-IC and induced tolerance in humanized FcRn mice. These
results suggest that maternal IgG-IC in breast milk and offspring CD11c+ DCs are critical for the induction of
Treg cell responses and control food-specific tolerance in neonates and that TGFβ may facilitate this effect.
 Q576R mice, a genetic murine model of atopy, carry the naturally-occurring interleukin (IL)-4 receptor
(IL-4R) α chain Q576R polymorphism associated with asthma and atopic dermatitis in humans. Offspring of
OVA-sensitized Q576R mothers showed a decrease in the frequencies of allergen-specific Treg cells and
suboptimal levels of tolerance against food allergy as compared to wild-type controls. This partial protection
was associated with lower levels of TGFβ in breast milk and dysregulation of intestinal CD11c+ DCs in
offspring. These results suggest that genetic predisposition of mothers and offspring to atopy may hinder
optimal induction of neonatal tolerance via modulation of maternal TGFβ and offspring DCs.
 The goals of this proposal are to decipher the time frame and the mechanistic interactions of
maternal factors and offspring immune responses critical to establish effective food-specific tolerance
in neonates, and how they are modulated by genetic susceptibilities to atopy. We hypothesize that
exposure of neonatal DCs to sufficient levels of TGFβ in breast milk during a specific time window in the
perinatal period is critical to generate functional Treg cells specific to maternally transferred allergen IgG-IC in
breast milk. We also hypothesize that excessive IL-4R signaling, a key signaling in the pro-allergic Th2
responses, modifies maternal TGFβ levels and offspring DC phenotype, and induces the reprograming of Treg
cells in offspring ...

## Key facts

- **NIH application ID:** 9828067
- **Project number:** 5R01AI142872-02
- **Recipient organization:** BOSTON CHILDREN'S HOSPITAL
- **Principal Investigator:** Michiko Oyoshi
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $518,598
- **Award type:** 5
- **Project period:** 2018-12-01 → 2021-11-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9828067

## Citation

> US National Institutes of Health, RePORTER application 9828067, Induction of food allergen-specific neonatal tolerance through breast milk (5R01AI142872-02). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/9828067. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*