Résumé
The Rosette and Orion nebulae are two young massive star clusters in which no supernova explosion has occurred yet. They are therefore good candidates to look for non thermal radiation originated by particle acceleration mechanisms taking place within stellar-wind bubbles (i.e. induced by the collective effects of stellar winds). The gamma-ray emission from these nebulae as observed by the Fermi-LAT together with prediction from a phenomenological model have been considered in this work. Upper limits on the fraction of mechanical energy converted into accelerated particles have been obtained. Finally the expected TeV θs-ray emission, which could be explored in the future with the advent of new generation gamma-ray observatories such as CTA, has been also considered..