Prediction, diagnosis and treatment of experimental graft-versus-host disease : an investigation of genomic, molecular and cellular factors in graft-versus-host disease and mesenchymal stromal cell therapy in a rat model of allogeneic stem cell transplantation
Patients who suffer from leukemia or lymphoma can be cured by the transplantation of bone marrow stem cells from a volunteer donor (allogeneic hematopoietic cell transplantation). Recipients frequently acquire an immune disorder known as graft-versus-host disease (GvHD) which represents the main hindrance of this therapeutic procedure at present. Graft-borne donor T cells are activated by disparate antigens in the host leading to a cascade of adverse immune reactions and damage of host tissues that give rise to clinical GvHD.
The objectives of this thesis were twofold: firstly, to develop diagnostic tools and identify reliable biomarkers of GvHD; secondly, to improve GvHD treatment by mesenchymal stromal cell (MSC) therapy.
In a collaborative effort, we helped develop the rat skin explant, an ex-vivo assay of GvHD, as well as a DNA microarray for the study of genetic factors that regulate GvHD. Analysis of gene expression in rat skin explants revealed MHC and innate immune receptor genes that were associated with graft-versus-host reactions and are thus of potential use as diagnostic biomarkers of GvHD. In a model of MHC-mismatched bone marrow transplantation that caused acute GvHD in rats, we isolated natural killer cell and T cell subsets including regulatory T cells that were differentially distributed in disease. Using this animal model, we also tested whether MSC injections could prevent GvHD. We concluded that repeated interventions failed to alleviate disease or improve survival in transplanted rats. In contrast, MSC potently suppressed T cell proliferation and cytokine secretion in vitro. Proliferation was inhibited through the enzymatic synthesis of nitric oxide.
In summary, this work resulted in the characterization of genetic and cellular markers of GvHD in the skin ex vivo and after transplantation in vivo as well as the isolation of nitric oxide synthesis as a key pathway used by rat MSC to inhibit allogeneic T cell responses in vitro.
List of papers. Papers I, II, IV and VI are removed from the thesis due to copyright restrictions.
Paper I Zinöcker S, Sviland L, Dressel R, Rolstad B Kinetics of lymphocyte development after allogeneic bone marrow transplantation: Markers of acute graft-versus-host disease. Journal of Leukocyte Biology, 2011, 90(1): 177-187 doi:10.1189/jlb.0211067
Paper II Novota P, Sviland L, Zinöcker S, Stocki P, Balavarca Y, Bickeböller H, Rolstad B, Wang XN, Dickinson AM, Dressel R Correlation of Hsp70-1 and Hsp70-2 gene expression with the degree of graftversus-host reaction in a rat skin explant model. Transplantation, 2008, 85(12): 1809-16 doi:10.1097/TP.0b013e31817753f7
Paper III Novota P, Zinöcker S, Norden J, Wang XN, Sviland L, Opitz L, Salinas-Riester G, Rolstad B, Dickinson AM, Walter L, Dressel R Expression profiling of major histocompatibility complex genes in skin explant assays reveals new candidates for controlling risk of graft-versus-host disease. PLoS ONE, 2011, 6(1): e16582 doi:10.1371/journal.pone.0016582 Published under a Creative Commons Attribution License.
Paper IV Zinöcker S, Vaage JT Rat bone marrow-derived mesenchymal stromal cells suppress T cell stimulation in vitro through nitric oxide production. Published as: Rat mesenchymal stromal cells inhibit T cell proliferation but not cytokine production through inducible nitric oxide synthase. Front Immunol. 2012;3:62. Epub 2012 Apr 2. doi:10.3389/fimmu.2012.00062
Paper V Zinöcker S, Wang MY, Gaustad P, Kvalheim G, Rolstad B, Vaage JT Mycoplasma contamination revisited: Mesenchymal stromal cells harboring Mycoplasma hyorhinis potently inhibit lymphocyte proliferation in vitro. PLoS ONE, 2011, 6(1): e16005 doi:10.1371/journal.pone.0016005 Published under a Creative Commons Attribution License.
Paper VI Zinöcker S, Rolstad B, Vaage JT Mesenchymal stromal cells fail to alleviate graft-versus-host disease in rats transplanted with major histocompatibility complex-mismatched bone marrow. Published as: Zinöcker S, Wang MY, Rolstad B, Vaage JT Mesenchymal stromal cells fail to alleviate experimental graft-versus-host disease in rats transplanted with major histocompatibility complex-mismatched bone marrow Scand J Immunol. 2012 Nov;76(5):464-70. doi:10.1111/j.1365-3083.2012.02758.x