- Poster presentation
- Open Access
Deficiency of regulatory B cells in a house dust mite model of asthma
© Braza et al; licensee BioMed Central Ltd. 2012
- Published: 28 November 2012
- Bronchial Obstruction
- Bronchial Hyperreactivity
- Specific Expansion
Asthma is a chronic disorder leading to bronchial obstruction in response to inhaled allergen. It is associated with immune deregulation with specific expansion of Th2 and Th17 CD4+ T cells. Both T cell populations support B cells response by stimulating their proliferation, survival and IgE secretion. B cells are described for their effector functions but recently reports have described their regulatory role in autoimmune and inflammatory disorders. However, definitive identification has been challenging because regulatory B cells (Breg) are rare, do not have a specific marker, and express detectable IL-10 or TGF-β only upon ex vivo stimulation. In OVA asthma models, local inhalation tolerance ,  and infections with helminthes ,  induce the generation of regulatory B cells. But no physiological role of this population in the development of asthma has been described yet.
Mice were sensitized on days 0, 7, 14 and 21 by percutaneous administration of HDM onto the ears. Intra-nasal challenges were performed on day 27 and 34 with 250 μg HDM. One day after each challenge, we realized by flow cytometry a complete B cell phenotyping in spleen and lungs.
Splenocytes and lung cells were isolated and stimulated ex vivo with LPS and PMA, ionomycin to induce IL-10 secretion by B cells.
No differential frequency was observed for all B cell populations in the spleen of HDM allergic mice, suggesting a normal B cell development. In contrast, HDM allergic mice exhibit a strong infiltration of CD19+ B cells in lungs and broncho-alveolar lavage after the second challenge. We found an increase of CD19 IgDhi IgMlow B2 mature and CD19 IgD- IgM- switched memory B cells in the lung of HDM allergic compared to control mice. We looked at CD19+ IL-10+ CD1dhi CD5+ CD21+ CD24hi IgMhi B cell population that has been shown to display regulatory properties in other situations. Whereas this population is present in spleen and lungs of HDM allergic mice, it produces less IL-10 than control after the first and the second challenge both in lung (vs control, p<0.01) and spleen (vs control, p<0.05).
Our results strongly suggest a potential defect of regulatory B cells in the course of asthma. Future investigations will focus on their capacities to inhibit bronchial hyperreactivity and inflammatory responses.
- Singh A, Carson WF, Secor ER, Guernsey LA, Flavell RA, Clark RB, Thrall RS, Schramm CM: Regulatory role of B cells in a murine model of allergic airway disease. J. Immunol. 2008, 180 (no. 11): 7318-7326.PubMed CentralView ArticlePubMedGoogle Scholar
- Natarajan P, Singh A, McNamara JT, Secor ER, Guernsey LA, Thrall RS, Schramm CM: Regulatory B cells from hilar lymph nodes of tolerant mice in a murine model of allergic airway disease are CD5(+), express TGF-β, and co-localize with CD4(+)Foxp3(+) T cells. T cells. 2012, 1-11.Google Scholar
- A S, S SP, K M, M NE, A A, F PG: Regulatory B cells prevent and reverse allergic airway inflammation via FoxP3-positive T regulatory cells in a murine model. Journal of Allergy and Clinical Immunology. 2010, 125 (no. 5): 1114-1124.e8. 10.1016/j.jaci.2010.01.018.View ArticleGoogle Scholar
- van der Vlugt LEPM, Labuda LA, Ozir-Fazalalikhan A, Lievers E, Gloudemans AK, Liu K-Y, Barr TA, Sparwasser T, Boon L, Ngoa UA, Feugap EN, Adegnika AA, Kremsner PG, Gray D, Yazdanbakhsh M, Smits HH: Schistosomes induce regulatory features in human and mouse CD1d(hi) B cells: inhibition of allergic inflammation by IL-10 and regulatory T cells. PLoS ONE. 2012, no. 7 (2): e30883-View ArticleGoogle Scholar
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.