All patients had experienced symptoms for a prolonged time period (mean time of disease 10±14 years) and presented with mucosal lesions involving the nasal cavity (100%), pharynx (35%) and/or larynx (11%). All tissue specimens were obtained before treatment; afterwards, patients received N-methylglucamine antimoniate (20 mg/Sb/kg/d) for 30 days. Nasal mucosal biopsy was performed under check details local anaesthesia with Lidocaine® spray (10%). Normal mucosal samples were obtained from turbinectomy nasal

surgery. Tissue fragments were cryopreserved or conserved in 10% formalin. This study was approved by the Gonçalo Moniz Research Center (CPqGM/FIOCRUZ-Bahia) Institutional Review Board, and informed consent was obtained from all patients before enrolment. Frozen sections (5 μm thick) were obtained and immunohistochemistry was performed as described previously 2. The following primary antibodies were used: rabbit anti-IL-17 (4 μg/mL) or anti-TGF-β (2 μg/mL) (both Santa Cruz Biotechnology, Santa Cruz, CA, USA), goat anti-IL-23 (0.01 μg/mL), mouse anti-IL-6 (25 μg/mL), mouse anti-IL-1β (10 μg/mL) PLX-4720 nmr or goat anti-MMP-9 (4 μg/mL) (all R&D Systems,

Abingdon, UK), goat anti-MPO (4 μg/mL; US Biological, Swampscott, MA, USA) and goat anti-NE (12 μg/mL; Santa Cruz Biotechnology). Biotin-labelled anti-rabbit, anti-mouse or anti-goat IgG (Vector Laboratories, Peterborough, 4��8C England) was used as a secondary antibody. Isotype control antibodies (R&D Systems) were used as negative controls. Positive-control sections consisted of frozen mucosal tonsillar tissue and frozen nasal polyps. Digital images of tissue sections were captured using a Nikon E600 light microscope and a Q-Color 1 Olympus digital camera. Quantification of stained areas was performed using Image Pro-Plus software (Media Cybernetics). Double immunofluorescence staining was performed for IL-17 and CD4, CD8, CD14 or

CCR6 markers. The following primary antibodies were used: mouse anti-CD4 (BD Biosciences, San Jose, CA, USA), mouse anti-CD8 (BD Biosciences), mouse anti-CCR6 (R&D Systems) and rabbit anti-IL-17 (8 μg/mL, Santa Cruz Biotechnology). Secondary antibodies were biotin anti-mouse IgG (Vector Laboratories) or anti-rabbit Alexa 488 (Molecular Probes, Eugene, OR, USA). Streptavidin Cy3 (Sigma, Buchs, Switzerland) was used after biotin antibodies. Multiple images representing positive staining and negative controls were acquired using a confocal microscope (Leica TCS SP2 SE and SP5 AOB5). Image Pro Plus was used for image processing. The extraction of total RNA from mucosal tissues was performed following the protocol recommended by the manufacturer (Life Technologies, Rockville, MD, USA). cDNA was synthesised using 1 μg of RNA through a reverse transcription reaction (M-MLV reverse transcriptase, Promega, Madison, WI, USA).