The role of immunomodulatory oligonucleotides in prevention of OVA-induced Eustachian tube dysfunction § Charles S. Ebert Jr. a, * , Austin S. Rose a , Mihir R. Patel a , Stuart M. Hardy a , Ekambar R. Kandimalla b , Sudhir Agrawal b , Jiri Prazma a , Harold C. Pillsbury III a a Department of Otolaryngology-Head and Neck Surgery, CB# 7070, G0412 Neurosciences Hospital, University of North Carolina School of Medicine, Chapel Hill, NC 27599-7070, United States b Idera Pharmaceuticals, Inc., 345 Vassar Street, Cambridge, MA, United States Received 27 February 2006; accepted 14 July 2006 International Journal of Pediatric Otorhinolaryngology (2006) 70, 2019—2026 www.elsevier.com/locate/ijporl KEYWORDS Oligonucleotide; Allergy; Otitis media; Transtympanic; Eustachian tube dysfunction Summary Objective: To evaluate the potential role of immunomodulatory oligonucleotides (IMO) in the prevention of OVA-induced Eustachian tube dysfunction (ETD) in a rat model. Methods: Brown—Norway rats were sensitized to ovalbumin (OVA) and randomized to receive pre-treatment with IMO or phosphate buffered saline (PBS). After systemic sensitization, subjects received a transtympanic OVA challenge followed by evalua- tion of the Eustachian tube’s dynamic function. Results: Pre-treatment of OVA sensitized animals with IMO normalized passive open- ing and closing Eustachian tube pressures, improved active clearance of negative pressure in the middle ear, and resulted in reduced mean mucociliary transit times compared to untreated OVA-sensitized animals (P < 0.001). Conclusion: These data demonstrate that pre-treatment with IMO prevent OVA- induced ETD in the rat. IMO treatment in the future may offer considerable promise in the management of OME in children. # 2006 Elsevier Ireland Ltd. All rights reserved. § Resident Research Award. Presented at the 2005 American Academy of Otolaryngic Allergy Annual Meeting, September 2005, Los Angeles, CA. * Corresponding author. Tel.: +1 919 966 3254; fax: +1 919 966 7656. E-mail address: cebert@med.unc.edu (C.S. Ebert Jr.). 0165-5876/$ — see front matter # 2006 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.ijporl.2006.07.016