PT  - JOURNAL ARTICLE
AU  - P. Robbe
AU  - M.J. Blacquière
AU  - D.S. Postma
AU  - W. Timens
AU  - M. Geerlings
AU  - A. Bufe
AU  - O. Holst
AU  - E. von Mutuis
AU  - M.N. Hylkema
TI  - Farm dust decreases Th2 driven allergic airway inflammation in mice: A role for airway TLR2 and TLR4?
DP  - 2011 Sep 01
TA  - European Respiratory Journal
PG  - p1844
VI  - 38
IP  - Suppl 55
4099  - http://erj.ersjournals.com/content/38/Suppl_55/p1844.short
4100  - http://erj.ersjournals.com/content/38/Suppl_55/p1844.full
SO  - Eur Respir J2011 Sep 01; 38
AB  - Exposure to farm dust is known to decrease allergic inflammation in an ovalbumin mouse model for asthma. However, the underlying mechanisms of this protection are not known. With the focus on the role of epithelium in this process, we investigated whether farm dust also protects against allergic airway inflammation in a more clinically relevant house dust mite (HDM) asthma mouse model.Dust from different farms in Germany was collected and pooled. BALB/c mice were exposed intranasally 4 times/week for 5 weeks to PBS or farm dust (1 mg/ml, 50 μl/day), followed by PBS or HDM (2.5 mg/ml, 10 μl/day). IgE levels, inflammatory cells, cytokines (CC chemokine ligand (CCL)20, thymic stromal lymphopoietin (TSLP) and Th2) and Toll-like receptor (TLR)2 and TLR4 expression on epithelial cells were assessed.Farm dust+HDM exposed mice had lower levels of HDM-specific IgE in serum, eosinophilic inflammation, and Th2 cytokines in lungs than HDM exposed mice. Expression of TLR2 and 4 in epithelium, and CCL20 and TSLP levels in lung tissue were lower in farm dust exposed than HDM exposed mice. Additionally, we observed less spindle shaped CD68+ cells beneath the epithelial basement membrane in farm dust exposed mice.Lower expression of TLR2 and 4 in epithelium after farm dust exposure may explain the lower levels epithelial cell-derived cytokines CCL20 and TSLP. These lower CCL20 and TSLP levels could have prevented the recruitment of antigen presenting cells as evidenced by the spindle shaped CD68+ cells, as well as the skewing towards a Th2 response. Hence, lower expression of TLR2 and 4 may contribute to the observed protection against HDM-induced allergic inflammation in farm dust-exposed mice.