Background: As passive environmental tobacco smoke (ETS) exposure in nonsmokers can increase both asthma symptoms and the frequency of asthma exacerbations, we utilized a mouse model, in which ovalbumin (OVA) + ETS induce significantly increased levels of eosinophilic airway inflammation and remodeling compared to either stimulus alone, to determine whether a Toll-like receptor-9 (TLR-9) agonist could reduce levels of airway inflammation, airway remodeling and airway hyperreactivity (AHR). Methods: Mice treated with or without a TLR-9 agonist were sensitized to OVA and challenged with OVA + ETS for 1 month. AHR to methacholine was assessed in intubated and ventilated mice. Lung Th2 cytokines and TGF-β1 were measured by ELISA. Lungs were processed for histology and immunohistology to quantify eosinophils, mucus, peribronchial fibrosis and smooth muscle changes using image analysis. Results: Administration of a TLR-9 agonist to mice coexposed to chronic ETS and chronic OVA allergen significantly reduced levels of eosinophilic airway inflammation, mucus production, peribronchial fibrosis, the thickness of the peribronchial smooth muscle layer, and AHR. The reduced airway remodeling in mice treated with the TLR-9 agonist was associated with significantly reduced numbers of peribronchial MBP+ and peribronchial TGF-β1+ cells, and with significantly reduced levels of lung Th2 cytokines [interleukin-5 and interleukin-13] and TGF-β1. Conclusion: These studies demonstrate that TLR-9-based therapies inhibit airway inflammation, remodeling and AHR in mice coexposed to ETS and allergen who exhibit enhanced airway inflammation and remodeling.

Keywords:
Toll-like receptor-9, Airway hyperreactivity, Airway inflammation, Airway remodeling, Eosinophils
1.
Busse WW, Lemanske R Jr: Asthma. N Engl J Med 2001;344:350–362.
2.
Lange P, Parner J, Vestbo J, Schnohr P, Jensen G: A 15-year follow-up study of ventilatory function in adults with asthma. N Engl J Med 1998;339:1194–1200.
3.
Silverman RA, Boudreaux ED, Woodruff PG, Clark S, Camargo CA: Cigarette smoking among asthmatic adults presenting to 64 emergency departments. Chest 2003;123:1472–1479.
4.
Chaudhuri R, Livingston W, McMahon AD, Lafferty J, Fraser I, Spears M, McSharry CP, Thomson NC: Effects of smoking cessation on lung function and airway inflammation in smokers with asthma. Am J Respir Crit Care Med 2006;174:127–133.
5.
Chilmonczyk BA, Salmun LM, Megathlin KN, Neveux LM, Palomaki GE, Knight GJ, Pulkkinen AJ, Haddow JE: Association between exposure to environmental tobacco smoke and exacerbations of asthma in children. N Engl J Med 1993;328:1665–1669.
6.
Eisner MD, Klein J, Hammond SK, Koren G, Lactao G, Iribarren C: Directly measured second hand smoke exposure and asthma health outcomes. Thorax 2005;60:814–821.
7.
Kumar R, Curtis LM, Khiani S, Moy J, Shalowitz MU, Sharp L, Durazo-Arvizu RA, Shannon JJ, Weiss KB: A community-based study of tobacco smoke exposure among inner-city children with asthma in Chicago. J Allergy Clin Immunol 2008;122:754–759.
8.
Bouzigon E, Corda E, Aschard H, Dizier MH, Boland A, Bousquet J, Chateigner N, Gormand F, Just J, le Moual N, Scheinmann P, Siroux V, Vervloet D, Zelenika D, Pin I, Kauffmann F, Lathrop M, Demenais F: Effect of 17q21 variants and smoking exposure in early-onset asthma. N Engl J Med 2008;359:1985–1994.
9.
Menon P, Rando RJ, Stankus RP, Salvaggio JE, Lehrer SB: Passive cigarette smoke-challenge studies: increase in bronchial hyperreactivity. J Allergy Clin Immunol 1992;89:560–566.
10.
Stankus RP, Menon PK, Rando RJ, Glindmeyer H, Salvaggio JE, Lehrer SB: Cigarette smoke-sensitive asthma: challenge studies. J Allergy Clin Immunol 1988;82:331–338.
11.
Centers for Disease Control and Prevention (CDC): Cigarette smoking among adults: United States, 2000. MMWR Morb Mortal Wkly Rep 2002;51:642–645.
12.
Min MG, Song DJ, Miller M, McElwain S, Ferguson P, Broide DH: Coexposure to environmental tobacco smoke increases levels of allergen-induced airway remodeling in mice. J Immunol 2007;178:5321–5328.
13.
Seymour BW, Pinkerton KE, Friebertshauser KE, Coffman RL, Gershwin LJ: Second-hand smoke is an adjuvant for Th2 responses in a murine model of allergy. J Immunol 1997;159:6169–6175.
14.
Rumold R, Jyrala M, Diaz-Sanchez DD: Second-hand smoke induces allergic sensitization in mice. J Immunol 2001;167:4765–4770.
15.
Chalmer GW, Macleod KJ, Little SA, Thomson LJ, McSharry CP, Thomson NC: Influence of cigarette smoking on inhaled corticosteroid treatment in mild asthma. Thorax 2002;57:226–230.
16.
Lazarus SC, Chinchilli VM, Rollings NJ, Boushey HA, Cherniack R, Craig TJ, Deykin A, DiMango E, Fish JE, Ford JG, Israel E, Kiley J, Kraft M, Lernanske RF, Leone FT, Martin RJ, Pesola GR, Peters SP, Sorkness CA, Szefler SJ, Wechsler ME, Fahy JV, National Heart, Lung, and Blood Institute’s Asthma Clinical Research Network: Smoking affects response to inhaled corticosteroids or leukotriene receptor antagonists in asthma. Am J Respir Crit Care Med 2007;175:783–790.
17.
Tomlinson JE, McMahon AD, Chaudhuri R, Thompson JM, Wood SF, Thomson NC: Efficacy of low and high dose inhaled corticosteroid in smokers versus non-smokers with mild asthma. Thorax 2005;60:282–287.
18.
Chaudhuri R, Livingston E, McMahon AD, Thomson L, Borland W, Thomson NC: Cigarette smoking impairs the therapeutic response to oral corticosteroids in chronic asthma. Am J Respir Crit Care Med 2003;168:1308–1311.
19.
Broide D, Schwarze J, Tighe H, Gifford T, Nguyen MD, Malek S, van Uden J, Martin-Orozco E, Gelfand EW, Raz E: Immunostimulatory DNA sequences inhibit IL-5, eosinophilic inflammation, and airway hyperresponsiveness in mice. J Immunol 1998;161:7054–7062.
20.
Ikeda RK, Miller M, Nayar J, Walker L, Cho JY, McElwain K, McElwain S, Raz E, Broide DH: Accumulation of peribronchial mast cells in a mouse model of ovalbumin allergen induced chronic airway inflammation: modulation by immunostimulatory DNA sequences. J Immunol 2003;171:4860–4867.
21.
Cho J, Miller M, Baek K, Han JW, Nayar J, Rodriguez M, Lee SY, McElwain K, McElwain S, Raz E, Broide DH: Immunostimulatory DNA inhibits transforming growth factor-β expression and airway remodeling. Am J Respir Cell Mol Biol 2004;30:651–661.
22.
Cho JY, Miller M, Baek KJ, Han JW, Nayar J, Lee SY, McElwain K, McElwain S, Raz E, Broide DH: Immunostimulatory DNA reverses established allergen-induced airway remodeling. J Immunol 2004;173:7556–7564.
23.
Lee SY, Cho JY, Miller M, McElwain K, McElwain S, Sriramarao P, Raz E, Broide DH: Immunostimulatory DNA inhibits allergen-induced peribronchial angiogenesis in mice. J Allergy Clin Immunol 2006;117:597–603.
24.
Cho JY, Miller M, McElwain K, McElwain S, Shim JY, Raz E, Broide DH: Remodeling associated expression of matrix metalloproteinase 9 but not tissue inhibitor of metalloproteinase 1 in airway epithelium: modulation by immunostimulatory DNA. J Allergy Clin Immunol 2006;117:618–625.
25.
Creticos PS, Schroeder JT, Hamilton RG, Balcer-Whaley SL, Khattignavong AP, Lindblad R, Li H, Coffman R, Seyfert V, Eiden JJ, Broide D, Immune Tolerance Network: Immunotherapy with a ragweed-toll-like receptor 9 agonist vaccine for allergic rhinitis. N Engl J Med 2006;355:1445–1455.
26.
Song DJ, Min MG, Miller M, Cho JY, Broide DH: Environmental tobacco smoke exposure does not prevent corticosteroids reducing inflammation, remodeling, and airway hyperreactivity in mice exposed to allergen. Am J Physiol Lung Cell Mol Physiol 2009; 297:L380–L387.
27.
Broide DH, Stachnick G, Castandeda D, Nayar J, Miller M, Cho JY, Roman M, Zubeldia J, Hayashi T, Raz E: Systemic administration of immunostimulatory SNA sequences mediates reversible inhibition of Th2 responses in a mouse model of asthma. J Clin Immunol 2001;21:175–182.
28.
Miller M, Cho JY, McElwain K, McElwain S, Shim JY, Manni M, Baek JS, Broide DH: Corticosteroids prevent myofibroblast accumulation and airway remodeling in mice. Am J Physiol Lung Cell Mol Physiol 2006;290:L162–L169.
29.
Lim DH, Cho JY, Song DJ, Lee SY, Miller M, Broide DH: PI3K gamma-deficient mice have reduced levels of allergen-induced eosinophilic inflammation and airway remodeling. Am J Physiol Lung Cell Mol Physiol 2009;296:L210–L219.
30.
Le AV, Cho JY, Miller M, McElwain S, Golgotiu K, Broide DH: Inhibition of allergen-induced airway remodeling in Smad 3-deficient mice. J Immunol 2007;178:7310–7316.
31.
McMillan SJ, Xanthou G, Lloyd CM: Manipulation of allergen-induced airway remodeling by treatment with anti-TGF-beta antibody: effect on the Smad signaling pathway. J Immunol 2005;174:5774–5780.
32.
Alcorn J, Rinaldi L, Jaffe E, van Loon M, Bates J, Janssen-Heininger Y, Irvin C: Transforming growth factor-β1 suppresses airway hyperresponsiveness in allergic airway disease. Am J Respir Crit Care Med 2007;176:974–982.
33.
Fattouh R, Midence G, Arias K, Johnson J, Walker T, Goncharova S, Souza K, Gregory R, Lonning S, Gauldie J, Jordana M: Transforming growth factor-β regulates house dust mite-induced allergic airway inflammation but not airway remodeling. Am J Respir Crit Care Med 2008;177:593–603.
34.
Eisner MD, Yelin EH, Henke J, Shiboski SC, Blanc PD: Environmental tobacco smoke and adult asthma: the impact of changing exposure status on health outcomes. Am J Respir Crit Care Med 1998;158:170–175.
35.
Akdis CA, Kussebi F, Pulendran B, Akdis M, Lauener RP, Schmidt-Weber CB, Klunker S, Isitmangil G, Hansjee N, Wynn TA, Dillon S, Erb P, Baschang G, Blaser K, Alkan SS: Inhibition of T helper 2-type responses, IgE production and eosinophilia by synthetic lipopeptides. Eur J Immunol 2003;33:2717–2726.
36.
Tulić MK, Wale JL, Holt PG, Sly PD: Modification of the inflammatory response to allergen challenge after exposure to bacterial lipopolysaccharide. Am J Respir Cell Mol Biol 2000;22:604–612.
37.
Camateros P, Tamaoka M, Hassan M, Marino R, Moisan J, Marion D, Guiot MC, Martin JG, Radzioch D: Chronic asthma-induced airway remodeling is prevented by toll-like receptor-7/8 ligand S28463. Am J Respir Crit Care Med 2007;175:1241–1249.
38.
Lefort J, Singer M, Leduc D, Renesto P, Nahori MA, Huerre M, Créminon C, Chignard M, Vargaftig BB: Systemic administration of endotoxin induces bronchopulmonary hyperreactivity dissociated from TNF-alpha formation and neutrophil sequestration into the murine lungs. J Immunol 1998;161:474–480.
39.
Redecke V, Häcker H, Datta SK, Fermin A, Pitha PM, Broide DH, Raz E: Cutting edge: activation of toll-like receptor 2 induces a Th2 immune response and promotes experimental asthma. J Immunol 2004;172:2739–2743.
40.
Hasday JD, Bascom R, Costa JJ, Fitzgerald T, Dubin W: Bacterial endotoxin is an active component of cigarette smoke. Chest 1999;115:829–835.
41.
Tighe H, Takabayashi K, Schwartz D, van Nest G, Tuck S, Eiden JJ, Kagey-Sobotka A, Creticos PS, Lichtenstein LM, Spiegelberg HL, Raz E: Conjugation of immunostimulatory DNA to the short ragweed allergen Amb a 1 enhances its immunogenicity and reduces its allergenicity. J Allergy Clin Immunol 2000;106:124–134.
42.
Marshall JD, Abtahi S, Eiden J, Tuck S, Milley R, Haycock F, Reid MJ, Kagey-Sobotka A, Creticos PS, Lichtenstein LM, van Nest G: Immunostimulatory sequence DNA linked to the Amb a 1 allergen promotes TH 1 cytokine expression while downregulating TH 2 cytokine expression in PBMCs from human patients with ragweed allergy. J Allergy Clin Immunol 2001;108:191–197.
43.
Simons FE, Shikishima Y, van Nest G, Eiden JJ, HayGlass KT: Selective immune redirection in humans with ragweed allergy by injecting Amb a 1 linked to immunostimulatory DNA. J Allergy Clin Immunol 2004;113:1144–1151.
44.
Tulic MK, Fiset PO, Christodoulopoulos P, Vaillancourt P, Desrosiers M, Lavigne F, Eiden J, Hamid Q: Amb a 1-immunostimulatory oligodeoxynucleotide conjugate immunotherapy decreases the nasal inflammatory response. J Allergy Clin Immunol 2004;113:235–241.
45.
Gauvreau GM, Hessel EM, Boulet LP, Coffman RL, O’Byrne PM: Immunostimulatory sequences regulate interferon-inducible genes but not allergic airway responses. Am J Respir Crit Care Med 2006;174:15–20.
46.
Fanucchi MV, Schelegle ES, Baker GL, Evans MJ, McDonald RJ, Gershwin LJ, Raz E, Hyde DM, Plopper CG, Miller LA: Immunostimulatory oligonucleotides attenuate airways remodeling in allergic monkeys. Am J Respir Crit Care Med 2004;170:1153–1157.
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