Task: Answer Verification
Input (English): Question: Does timothy grass pollen major allergen Phl p 1 activate respiratory epithelial cells by a non-protease mechanism?
Answer: We conclude that under physiological conditions Phl p 1 affects tracheal epithelial cells through a non-proteolytic activity. Enhancement of TGF-beta expression induced by Phl p 1 together with the increased release of IL-6 and IL-8 might provide an indirect mechanism through which the allergen may cross the epithelial barrier and attracts immunocompetent cells.
Output (English): yes