Reduction of IFN-I responses by plasmacytoid dendritic cells in a longitudinal trans men cohort
Benjamin Grünhagel, Malte Borggrewe, Sven Hendrik Hagen, Susanne Ziegler, Florian Henseling, Laura Glau, Rebecca-Jo Thiele, Maria Pujantell, Varshi Sivayoganathan, Benedetta Padoan, Janna Marieke Claussen, Arne Düsedau, Jana Hennesen, Madeleine J. Bunders, Stefan Bonn, Eva Tolosa, Christian F. Krebs, Christoph Dorn, Marcus Altfeld
Abstract
Type I interferons (IFN-I) are important mediators of antiviral immunity and autoimmune diseases. Female plasmacytoid dendritic cells (pDCs) exert an elevated capacity to produce IFN-I upon toll-like receptor 7 (TLR7) activation compared to male pDCs, and both sex hormones and X-encoded genes have been implicated in these sex-specific differences. Using longitudinal samples from a trans men cohort receiving gender-affirming hormone therapy (GAHT), the impact of testosterone injections on TLR7-mediated IFN-I production by pDCs was assessed. Single-cell RNA analyses of pDCs showed downregulation of IFN-I-related gene expression signatures but also revealed transcriptional inter-donor heterogeneity. Longitudinal quantification showed continuous reduction of IFN-I protein production by pDCs and reduced expression of IFN-I-stimulated genes in peripheral blood mononuclear cells (PBMCs). These studies in trans men demonstrate that testosterone administration reduces IFN-I production by pDCs over time and provide insights into the immune-modulatory role of testosterone in sex-specific IFN-I-mediated immune responses.