Breast milk-mediated transfer of an antigen induces tolerance and protection from allergic asthma

Verhasselt et al. Nat. Med. 14, 170-175 (2008)

Speaker: Shih-Ping Chang                               Time: 15:00~16:00, Apr. 9, 2008

Commentator: Dr. Jiu-Yao Wang                    Place: Room 601

Abstract:

Asthma is a hyperreactive disease in airway caused by inappropriate Th2 responses to environmental allergens. And many factors involving in the responses, such as eosinophils, IL-4, IL-13, and mast cells, may cause mucus plugging and bronchoconstriciton.These responses eventually make the airway smaller, and less air is available. There are more than 300 million people in the world that suffer from asthma, and most cases are related to the exposure of environmental allergens in their early life¹. And still we don’t have efficient strategies for asthma treatment to date. Breastfeeding is said to be one of the strategies for asthma prevention in neonates. However, researches about whether breastfeeding protects neonates from asthma have reached different results². Also the mechanism responsible for asthma prevention is not yet clear. Here the authors use a murine model to address this issue. And they found that the exposure of breastfeeding mother mice to an airborne antigen affects the asthma development in progeny. Mice breast-fed by antigen-exposed mother showed milder asthma symptoms, lower immunoglobulin levels, and decreased T cell responses. And these were the results of antigen-specific protection, which was caused by both antigen and TGF-β in the breast milk transferred to neonates. TGF-β signaling and regulatory CD4⁺ T lymphocytes in neonates may be responsible for the induction of tolerance to protect mice from asthma. As a whole, these results strongly support the concept that breastfeeding can reduce the risk of asthma development, and reveal the mechanism that responsible for it. And this research may help the development of new strategies for allergic disease treatment.

References:

1.      Holt, P.G. & Thomas, W.R. Sensitization to airborne environmental allergens: unresolved issues. Nat. Immunol. 6, 957-960 (2005).

2.       Guilbert, T.W., Stern, D.A., Morgan, W.J., Martinez, F.D. & Wright, A.L. Effect of breastfeeding on lung function in childhood and modulation by maternal asthma and atopy. Am. J. Respir. Crit. Care Med. 176, 843-848 (2007).