title: Human regulatory macrophages as a cell-based medicinal product.
abstract: OBJECTIVE
  To consolidate our basic scientific and technological appreciation of human regulatory macrophages (M reg) as a cell-based medicinal product for use as an adjunct immunosuppressive therapy in organ transplantation.
  
  
  RESULTS
  Building on the original observation that crude preparations of IFN-γ-stimulated allogeneic macrophages prolong allograft survival in experimental animals, we have arrived at a detailed understanding of the derivation, phenotype and T-cell-suppressive potential of a population of in-vitro-derived human macrophages, which have been designated M regs. This basic scientific knowledge has inspired methodological advances in M reg manufacture, leading to a purer and more homogeneous cell product. In turn, cells produced by these improved protocols have been applied in the clinic, so completing a cycle of technological development. Studying the migration and physiological impact of M reg administration in patients provides a measure of reassurance that the procedure is well tolerated. Cutting-edge strategies to assess the immunological status of solid organ transplant recipients allow the biological effects of M reg treatment to be monitored.
  
  
  CONCLUSIONS
  A view of the human M reg as a novel, stringently defined medicinal product is presented, opening exciting possibilities for its future investigation as a therapy in solid organ transplantation and beyond.
authors.affiliation: Department of Surgery, Laboratory for Transplantation Research, University Hospital Regensburg, Franz-Josef-Strauss-Allee 11, Regensburg, Germany. james.hutchinson@klinik.uni-regensburg.de
authors.forename: James A
authors.initials: JA
authors.lastname: Hutchinson
authors.forename: Paloma
authors.initials: P
authors.lastname: Riquelme
authors.forename: Edward K
authors.initials: EK
authors.lastname: Geissler
mesh_terms: D000818:Animals; D002986:Clinical Trials as Topic; D006084:Graft Rejection / Q000276:immunology / Q000517:prevention & control*; D006085:Graft Survival / Q000276:immunology*; D006801:Humans; D008264:Macrophages / Q000276:immunology* / Q000637:transplantation*; D016377:Organ Transplantation; D023001:Transplantation Tolerance / Q000276:immunology*; D014184:Transplantation, Homologous / Q000276:immunology*