Combined Stimulation of Nasal Polyp Fibroblasts With Poly IC, Interleukin 4, and Tumor Necrosis Factor α Potently Induces Production of Thymus- and Activation-Regulated Chemokine

Objective To examine the effects of cytokines and poly IC on the expression of thymus- and activation-regulated chemokine (TARC), a potent chemoattractant for helper T-cell type 2 (T H 2) cells, in nasal polyp fibroblasts. Design Quantitative reverse transcription–polymerase chain reaction (RT-PCR) analysis. Setting Academic research. Participants Primary fibroblast lines were established from human nasal polyp biopsy tissue specimens (n = 5) removed at polypectomy. Main Outcome Measures The expression of TARC messenger RNA (mRNA) was evaluated by real-time RT-PCR. The amount of TARC in the supernatants was measured by enzyme-linked immunosorbent assay. Results Combined stimulation with interleukin 4 (IL-4) and tumor necrosis factor α (TNF-α) or with poly IC and IL-4 induced TARC production. Combined exposure of cells to poly IC, IL-4, and TNF-α resulted in substantial amounts of TARC release into the culture medium. Quantitative RT-PCR analysis revealed that simultaneous stimulation with those 3 compounds induced a tremendous increase in the amount of TARC mRNA in the nasal polyp fibroblasts. Conclusion Nasal polyp fibroblasts contribute to T H 2 cell infiltration and RNA virus–induced exacerbation of T H 2-type airway inflammatory conditions such as allergic chronic sinusitis.