title: Generation of suppressive blood cells for control of allograft rejection.
abstract: Our previous studies in rats showed that incubation of monocytic dendritic cells (DCs) with the chemotherapeutic drug mitomycin C (MMC) renders the cells immunosuppressive. Donor-derived MMC-DCs injected into the recipient prior to transplantation prolonged heart allograft survival. Although the generation of DCs is labour-intensive and time-consuming, peripheral blood mononuclear cells (PBMCs) can be easily harvested. In the present study, we analyse under which conditions DCs can be replaced by PBMCs and examine their mode of action. When injected into rats, MMC-incubated donor PBMCs (MICs) strongly prolonged heart allograft survival. Removal of monocytes from PBMCs completely abrogated their suppressive effect, indicating that monocytes are the active cell population. Suppression of rejection was donor-specific. The injected MICs migrated into peripheral lymphoid organs and led to an increased number of regulatory T-cells (Tregs) expressing cluster of differentiation (CD) markers CD4 and CD25 and forkhead box protein 3 (FoxP3). Tolerance could be transferred to syngeneic recipients with blood or spleen cells. Depletion of Tregs from tolerogenic cells abrogated their suppressive effect, arguing for mediation of immunosuppression by CD4⁺CD25⁺FoxP3⁺ Tregs. Donor-derived MICs also prolonged kidney allograft survival in pigs. MICs generated from donor monocytes were applied for the first time in humans in a patient suffering from therapy-resistant rejection of a haploidentical stem cell transplant. We describe, in the present paper, a simple method for in vitro generation of suppressor blood cells for potential use in clinical organ transplantation. Although the case report does not allow us to draw any conclusion about their therapeutic effectiveness, it shows that MICs can be easily generated and applied in humans.
authors.affiliation: *Department of Transplantation Immunology, Institute for Immunology, University of Heidelberg, 69120 Heidelberg, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Kleist
authors.affiliation: *Department of Transplantation Immunology, Institute for Immunology, University of Heidelberg, 69120 Heidelberg, Germany.
authors.forename: Flavius
authors.initials: F
authors.lastname: Sandra-Petrescu
authors.affiliation: †Department of Vascular Surgery, Division of Reconstructive Microsurgery, Victor Babes University of Medicine and Pharmacy, 300041 Timisoara, Romania.
authors.forename: Lucian
authors.initials: L
authors.lastname: Jiga
authors.affiliation: *Department of Transplantation Immunology, Institute for Immunology, University of Heidelberg, 69120 Heidelberg, Germany.
authors.forename: Laura
authors.initials: L
authors.lastname: Dittmar
authors.affiliation: *Department of Transplantation Immunology, Institute for Immunology, University of Heidelberg, 69120 Heidelberg, Germany.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Mohr
authors.affiliation: ‡Department of Hematology and Oncology, Center for Child and Adolescent Medicine, University of Heidelberg, 69120 Heidelberg, Germany.
authors.forename: Johann
authors.initials: J
authors.lastname: Greil
authors.affiliation: §Department of Radiology, Division of Nuclear Medicine, University of Heidelberg, 69120 Heidelberg, Germany.
authors.forename: Walter
authors.initials: W
authors.lastname: Mier
authors.affiliation: ║Department of Internal Medicine I, Division of Nephrology, University of Heidelberg, 69120 Heidelberg, Germany.
authors.forename: Luis E
authors.initials: LE
authors.lastname: Becker
authors.affiliation: ¶Department of Pediatric Oncology, Children's University Hospital, University of Tuebingen, 72076 Tuebingen, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Lang
authors.affiliation: *Department of Transplantation Immunology, Institute for Immunology, University of Heidelberg, 69120 Heidelberg, Germany.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Opelz
authors.affiliation: *Department of Transplantation Immunology, Institute for Immunology, University of Heidelberg, 69120 Heidelberg, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Terness
mesh_terms: D064591:Allografts; D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D002469:Cell Separation / Q000379:methods; D002478:Cells, Cultured; D002648:Child; D005260:Female; D051858:Forkhead Transcription Factors / Q000378:metabolism; D006084:Graft Rejection / Q000276:immunology / Q000378:metabolism / Q000517:prevention & control*; D006085:Graft Survival; D016027:Heart Transplantation / Q000009:adverse effects*; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D053645:Interleukin-2 Receptor alpha Subunit / Q000378:metabolism; D016030:Kidney Transplantation / Q000009:adverse effects*; D008297:Male; D016685:Mitomycin / Q000494:pharmacology; D009000:Monocytes / Q000187:drug effects / Q000276:immunology / Q000378:metabolism / Q000637:transplantation*; D036102:Peripheral Blood Stem Cell Transplantation / Q000009:adverse effects*; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000601:surgery*; D011914:Rats, Inbred BN; D011917:Rats, Inbred Lew; D013552:Swine; D050378:T-Lymphocytes, Regulatory / Q000276:immunology / Q000378:metabolism; D013997:Time Factors; D023001:Transplantation Tolerance; D016896:Treatment Outcome
chemical_list: D015415:Biomarkers; D051858:Forkhead Transcription Factors; C500522:Foxp3 protein, rat; D007166:Immunosuppressive Agents; D053645:Interleukin-2 Receptor alpha Subunit; D016685:Mitomycin