A conserved role for a GATA transcription factor in regulating epithelial innate immune responses.

Innate immunity is an ancient and conserved defense mechanism. Although host responses toward various pathogens have been delineated, how these responses are orchestrated in a whole animal is less understood. Through an unbiased genome-wide study performed in Caenorhabditis elegans, we identified a conserved function for endodermal GATA transcription factors in regulating local epithelial innate immune responses. Gene expression and functional RNAi-based analyses identified the tissue-specific GATA transcription factor ELT-2 as a major regulator of an early intestinal protective response to infection with the human bacterial pathogen Pseudomonas aeruginosa. In the adult worm, ELT-2 is required specifically for infection responses and survival on pathogen but makes no significant contribution to gene expression associated with intestinal maintenance or to resistance to cadmium, heat, and oxidative stress. We further demonstrate that this function is conserved, because the human endodermal transcription factor GATA6 has a protective function in lung epithelial cells exposed to P. aeruginosa. These findings expand the repertoire of innate immunity mechanisms and illuminate a yet-unknown function of endodermal GATA proteins.