Retaining the quality of teachers and improving teacher education and professional development through professional learning communities (PLCs) has long been on the policy agenda of, among others, the United Nations Educational, Scientific and Cultural Organization (UNESCO), Organisation for Economic Co-operation and Development (OECD), and the Framework for 21st Century Skills. This study explores and compares student-teachers' use of PLCs in Danish teacher education institutions and how PLCs are shaped by institutional, organising themes. An 'organising theme' is conceptualised as a fundamental 'idea' of how -- for instance institutional -- everyday practices become organised; exploring how institutional organising themes are translated into educational practice in students' PLCs makes it possible to understand how local moral worlds in teacher education institutions shape students' communal work and professional development. Drawing on situated learning, social anthropology of institutions and the literature about PLCs, the professional narratives of three Danish student-teachers are compared. The findings suggest that professional development in PLCs takes place in the intersection between personal stories, situated learning in PLCs and institutional themes.