Volume 1 Supplement 1
Oral tolerance and functional Treg cells are induced in BALB/c mice after gavage with bovine β-lactoglobulin (BLG)
© Adel-Patient et al; licensee BioMed Central Ltd. 2011
Published: 12 August 2011
Food allergy is considered as resulting from an impaired development of oral tolerance, or a breakdown in existing oral tolerance. We then aimed to induce oral tolerance to a major cow's milk allergen, BLG, which could prevent further systemic allergic sensitization and elicitation. Mechanisms involved were investigated.
BALB/cJ mice were gavaged with PBS (control mice) or with 2 mg of purified BLG on days 1, 2, 3, 8, 9 and 10. All mice were then sensitized by i.p. administration of 5 µg of BLG in alum on day 14. Mice sensitization was assessed by quantitative measurement of BLG-specific IgE and IgG1 antibodies on individual serum samples collected on day 36. After a boost administration of BLG/alum, elicitation of the allergic reaction was induced by intra-nasal administration of BLG. Bronchoalveolar lavage fluids (BAL) were collected 24h later and their cellular composition was analysed using simultaneous labelling with anti-CD3, anti-B220, anti-CMHII, anti-CD11c and anti-CCR3 or with anti-CD4 and anti-Foxp3 antibodies. In parallel, Th1/Th2/Th17 cytokines were assayed on centrifuged BAL.
Both allergic sensitization and elicitation were efficiently induced in control mice, as demonstrated by the high levels of anti-BLG IgE and IgG1 antibodies in sera, and IL-4, IL-5, GM-CSF and eotaxin release and eosinophil influx in BAL. Conversely, BLG-specific IgE and IgG1 antibody productions, as well as cytokine secretion and eosinophil recruitment in BAL, were totally inhibited in mice gavaged with BLG before sensitization. Interestingly, a high percentage of Foxp3+ cells within CD4+ cell population and a negative correlation between the number of eosinophils and the percentage of Foxp3+ cells were evidenced in BAL of mice gavaged with BLG.
Both inhibition of the allergic sensitization and active suppression of effector cells by Foxp3+ cells at the challenging site may contribute to the efficient systemic tolerance in BALB/c mice after gavage with BLG.
This article is published under license to BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.