Immunodeficiency and other clinical immunology Synthesis of interleukin-la, interleukin-6, and interleukin-8 by cultured human nasal epithelial cells

Nasal epithelium forms the initial barrier between the environment and the respiratory system and may be a potential source of proinflammatory interleukim, which contribute to the pathophysiology of allergic and nonallergic rhinitis. To explore this possibili~ epithelium and cultured human nasal epithelial cells from nasal turbinates of patients undergoing surgery for treatment of upper airway obstruction were examined for the spontaneous expression of interleukin (IL)-l o; IL-I ~, IL-6, and IL-8. Human nasal epithelial cell lysates and culture supernatants were assayed by two-site ELISAs specific for IL-l o~ IL-l [3, IL-6, or IL-8. Maximum concentrations of these cytokines in supernatants ranged from approximately 0.2 to 2 ng/mlfor IL-lo~ 1.5 to 7 ng/mlfor IL-6, and 100 to 3000 ng/mlfor IL-8. IL-la was predominantly cell-associated, whereas most of the IL-8 and all of the IL-6 were detected in the supernatant. Little or no 1L-113 was detected by ELISA in the supernatants or cell lysates. Whole tissue turbinates and isolated epithelium were also examined for IL-113, 1L-6, and IL-8 mRNA expression by Northern blot analysis. IL-6 and IL-8 mRNAs were detected, whereas IL-113 mRNA was not. Furthermore, IL-6 and IL-8 release from human nasal epithelial cell cultures was enhanced by addition to the cultures of lipopolysaccharide, and 1L-6 release was inhibited by polymyxin B. Thus human nasal epithelium may be a major source of lL-l o~ IL-6, and IL-8 in allergic and nonallergic rhinitis. Production of those proinflammatory cytokines by epithelial cells of the nasal and sinus mucosa may contribute to the pathologic and clinical events that occur in these diseases. (J ALLERGY CLIN IMMUNOL 1994;93:1060-7.)