NEUROIMMUNOLOGYMHC expression after human neural stem cell transplantation to brain contused ratsAl Nimer, FaiezCA; Wennersten, André; Holmin, Staffan; Meijer, Xia1; Wahlberg, Lars1; Mathiesen, TiitAuthor Information Department of Clinical Neuroscience, Section of Neurosurgery, Karolinska Institute, Stockholm, Sweden; 1NS Gene A/S, Copenhagen, Denmark CACorresponding Author: [email protected] Received 15 May 2004; accepted 12 June 2004 NeuroReport: August 26, 2004 - Volume 15 - Issue 12 - p 1871-1875 Buy Abstract Human neural stem cells survive and improve motor function after transplantation to the contused brain. However, the transplants might be rejected and that depends on the graft immunogenicity, the host immunological status and the immunosuppression strategy. We transplanted human neural stem cells to rats with brain contusion and analyzed the donor and host MHC antigen expression and the effect of a short-term immunosuppression with cyclosporine. In vitro human neural stem cells expressed only MHC-II antigens. This expression was down-regulated 6 weeks after transplantation. The host response was characterized by an increased MHC-II expression which was down-regulated by a longer term of immunosuppression. These findings are novel and necessary in order to understand the immunogenicity of human neural stem cell grafts. © 2004 Lippincott Williams & Wilkins, Inc.