Based on work in anthropology and the experience of the implementation of a project on ethics, this article describes the contributions of the ANRS 1215 cohort to information of participants and community involvement in research. It draws a parallel between the development of information methods and the roles gradually held by PLWA individually or collectively. From 1998 to 2011, the PLWA have diversified theirs activities (psycho-social support, administrative tasks, ethical watch function) and have contributed to improve the information of participants. This involvement of PLWHIV in ethics, which belongs to a long-term process, is analyzed through social, political, economical and ethical evolutions, both at national and international level.