title: Immune modulation as a therapeutic strategy in bone regeneration.
abstract: We summarize research approaches and findings on bone healing and regeneration that were presented at a workshop at the 60th annual meeting of the Orthopedic Research Society (ORS) in New Orleans in 2014. The workshop was designed to discuss the role of inflammation in bone regeneration in the context of fundamental biology, and to develop therapeutic strategies that involve immune modulation. Delayed or non-healing of bone is a major clinical problem, with around 10% of fracture patients suffering from unsatisfying healing outcomes. Inflammation is traditionally seen as a defense mechanism, but was recently found essential in supporting and modulating regenerative cascades. In bone healing, macrophages and T- and B-cells interact with progenitor cells, bone forming osteoblasts and remodeling osteoclasts. Among the cells of the innate immunity, macrophages are promising candidates for targets in immune-modulatory interventions that would overcome complications in bone healing and bone-related diseases. Among the cells of the adaptive immune system, CD8+ T cells have been shown to have a negative impact on bone fracture healing outcome, whereas regulatory T cells could be promising candidates that have a positive, modulating effect on bone fracture healing. This workshop addressed recent advances and key challenges in this exciting interdisciplinary research field.
authors.affiliation: Julius Wolff Institut and Center for Musculoskeletal Surgery, Charité - Universitätsmedizin Berlin, Augustenburger Platz 1, 13353, Berlin, Germany. claudia.schlundt@charite.de.|Berlin-Brandenburg Center for Regenerative Therapies, Charité - Universitätsmedizin Berlin, Augustenburger Platz 1, 13353, Berlin, Germany. claudia.schlundt@charite.de.
authors.forename: Claudia
authors.initials: C
authors.lastname: Schlundt
authors.affiliation: Julius Wolff Institut and Center for Musculoskeletal Surgery, Charité - Universitätsmedizin Berlin, Augustenburger Platz 1, 13353, Berlin, Germany. hanna.schell@charite.de.
authors.forename: Hanna
authors.initials: H
authors.lastname: Schell
authors.affiliation: Department of Orthopaedic Surgery and (by courtesy) Bioengineering, Stanford University Medical Center Outpatient Center, 450 Broadway St., M/C 6342, 94063, Redwood City, CA, USA. goodbone@stanford.edu.
authors.forename: Stuart B
authors.initials: SB
authors.lastname: Goodman
authors.affiliation: Department of Biomedical Engineering and Department of Medicine, Columbia University, 622 west 168th Street, VC12-234, 10032, New York, NY, USA. gv2131@columbia.edu.
authors.forename: Gordana
authors.initials: G
authors.lastname: Vunjak-Novakovic
authors.affiliation: Julius Wolff Institut and Center for Musculoskeletal Surgery, Charité - Universitätsmedizin Berlin, Augustenburger Platz 1, 13353, Berlin, Germany. georg.duda@charite.de.|Berlin-Brandenburg Center for Regenerative Therapies, Charité - Universitätsmedizin Berlin, Augustenburger Platz 1, 13353, Berlin, Germany. georg.duda@charite.de.
authors.forename: Georg N
authors.initials: GN
authors.lastname: Duda
authors.affiliation: Julius Wolff Institut and Center for Musculoskeletal Surgery, Charité - Universitätsmedizin Berlin, Augustenburger Platz 1, 13353, Berlin, Germany. katharina.schmidt-bleek@charite.de.|Berlin-Brandenburg Center for Regenerative Therapies, Charité - Universitätsmedizin Berlin, Augustenburger Platz 1, 13353, Berlin, Germany. katharina.schmidt-bleek@charite.de.
authors.forename: Katharina
authors.initials: K
authors.lastname: Schmidt-Bleek
keywords: Bone healing; Immune modulation; Macrophages; Osteoimmunology; Regeneration; Revascularization