This study seeks to investigate the effect of pre-service foreign language teachers' interactions on their continuing professional development (CPD), using a theoretical instructional design framework consisted of the three presence indicators of a Community of Inquiry (CoI) model and the Jigsaw teaching technique. The investigation was performed through a case study with thirty-five (n = 35) teachers who participated voluntarily in three consecutive tasks, by blending Sloodle as a free plug-in via the three-dimensional (3D) multi-user virtual world Open Simulator (Open Sim), with the purpose of creating virtual learning environments. A mixed-method research was conducted to be measured pre-service teachers' engagement, using a validated CoI model questionnaire proposed by Arbaugh et al. (2008) for collecting the quantitative data, and secondly their opinions for participation, achievements, abilities and difficulties, when studying collaboratively with their peers for gathering the qualitative data, after finishing several learning tasks. The study findings indicate that collaborative practice-based tasks in synchronous communication modes, such as group work, team effort, instructor's or peer feedback and consolidated learning material in a 3D multi-user virtual environment have enhanced the learning experience for more meaningful outcomes. The highest mean scores were adequately addressed to the teaching and social presences, indicating that pre-service teachers were enough satisfied due to the easy expression of proposals and the sense of freedom for exchanging ideas/opinions with their colleagues. This study contributes on the fundamental issues of cooperation, socialization, retention and attendance rates rising among teachers' interactions with the respect to empower not only their CPD, but also their management and learning responsibilities, based on the affordances that a 3D technology-enhanced environment can provide.