Interleukin-1 facilitates airway epithelial migration in response to injury

Objective: To test the hypothesis that interleukin (IL)-1 plays a permissive role in respiratory epithelial cell migration and proliferation. Study Design: Primary cultures of porcine respiratory epithelial cells or tracheal organ explants were cultured in the presence or absence of function-blocking antibodies to IL-1. Areas of epithelial cell outgrowth were determined in control and antibody-treated organ explants daily for 4 days. At intervals, cultured cells were collected for cell counting and viability determination. Time course and dose-response curves were constructed for control and antibody-treated groups. Results: Interleukin-1 secretion into culture supernatants increased sharply from days 3 to 7. Outgrowths from tracheal explants were reduced by greater than 60% by single antibody treatment, and by over 90% by treatment with antibodies to both IL-1α and -1β by day 4 of culture. Function-blocking antibodies to IL-1 significantly reduced cell number by day 7 of culture. Conclusions: Interleukin-1 is produced by respiratory epithelial cells in culture during log phase growth and plays a permissive role in cell migration and proliferation.