Cigarette smoke extract exposure affects larval innate immune response, metabolic rate and locomotion of Drosophila melanogaster.

Drosophila melanogaster is a widely used animal model in human diseases. Yet, its use in respiratory medicine is not frequent. In this study we aimed at investigating the effects of different concentrations of cigarette smoke extract (CSE) exposure on their innate immunity activation, metabolic rate and locomotion. Wild-type flies were held in vials containing CSE-infused culture media at concentrations of 10%, 25%, and 50% for three days, and their offspring were reared under the same conditions before measuring their body size and mating behavior. CSE exposure during development (in larval state) increased the activation of crystal cells, the main cellular mediator of innate immunity, in a concentration dependent manner, and similar results were obtained in the melanization assays which functionally demonstrates the innate immune response to tissue injury. Metabolic rate as measured by CO2 production was increased in male flies exposed to 50% CSE, while no difference was observed in females. Finally, locomotor activity was reduced in female and male flies exposed to 10% and 25% CSE respectively. Our findings indicate that CSE exposure leads to increased innate immunity activity, increases metabolic activity in high doses and negatively affects the locomotion in certain doses. Our model can be used for the study innate immune and metabolic effects of smoking rendering it of translational value.