Abstract
Background: The role of breast-feeding in the development of oral tolerance and allergic diseases is controversial, which could be related to variability in milk components. Toll-like receptor 2 (TLR2) is an innate immune receptor implicated in regulating allergic disease development. Objectives: We examined whether deficiency of maternal TLR2 affects the normal development of oral tolerance and related immune parameters during lactation in a mouse model. Methods: Heterozygous TLR2+/– pups from wild-type (WT) or TLR2–/– dams were fed either by their biologic dam or a dam of the alternate genotype. Development of oral tolerance to ovalbumin, levels of tolerogenic CD103+ dendritic cells, and regulatory T (Treg) cells, as well as intestinal permeability, were evaluated in these pups. The levels of key immune mediators in milk from TLR2–/– and WT mothers were also examined. Results: Heterozygous TLR2+/– pups that were born to and nursed by TLR2–/– dams exhibited impaired oral tolerance. This was prevented by cross-fostering onto WT (TLR2+/+) dams. Impairments included selective elevation in anti-ovalbumin IgE in plasma following immunization, reduced numbers of tolerogenic dendritic cells and Treg cells in the intestinal tract, and increased intestinal permeability. TLR2 deficiency also affected milk content of insulin-like growth factor-1, IFN-γ, IL-6, and IL-13. Conclusion: Our results underline a critical role for TLR2 in regulating milk components that are essential for development of oral tolerance in early life and demonstrate the importance of considering the immune status of nursing mothers in studies of immune development and responses.
Original language | English |
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Pages (from-to) | 631-641.e8 |
Journal | Journal of Allergy and Clinical Immunology |
Volume | 146 |
Issue number | 3 |
DOIs | |
Publication status | Published - Sept 2020 |
Bibliographical note
Funding Information:Supported by the Canadian Institutes of Health Research and AllerGen NCE. B. Dawod was supported by a Scotia Scholars award from the Province of Nova Scotia and by the Dalhousie Medical Research Foundation. M. B. Azad is supported by a Tier 2 Canada Research Chair in the Developmental Origins of Chronic Disease.
Funding Information:
We thank all the staff that helped in Dr Jean Marshall’s laboratory to accomplish this work. We are grateful to Alexander Edgar, Barakat Alrashdi, and Nong Xu for their scientific and technical assistance. Dr Azad is supported by a Tier 2 Canada Research Chair in the Developmental Origins of Chronic Disease. This work was funded by Canadian Institutes of Health Research grants MOP 93517 and PJT-156155 and by AllerGen NCE.
Publisher Copyright:
© 2020 The Authors
ASJC Scopus Subject Areas
- Immunology and Allergy
- Immunology
PubMed: MeSH publication types
- Journal Article
- Research Support, Non-U.S. Gov't