Leptin knockdown reduces innate immune function in zebrafish

Abstract

We investigated innate immune function in developing zebrafish with reduced leptin expression (via antisense morpholino technology). Leptin is a pleiotropic, adipose derived hormone known to be involved in mammalian lipid mobilization and storage, as well as the maintenance of many peripheral systems such as immune function. Despite many well‐described effects in mammals, leptin's function(s) in lower vertebrates are still poorly resolved. A fluorescent strain of P. aeruginosa was used to challenge the immune system of developing zebrafish and to visualize the progression of infection. Leptin knockdown significantly reduced the ability to fight invading pathogens, which was reflected in both reduced survivability and increased bacterial load of leptin morphants. Overall, these data suggest that leptin signaling influences innate immune function in fishes as it does in mammals, and promotes zebrafish as another vertebrate model for studying leptin function.