Submitted March 15, 2007
Accepted September 3, 2007
Immunogenicity of umbilical cord tissue derived cells
Patricia S Cho, Darin J Messina, Erica L Hirsh, Nina Chi, Stephanie N Goldman, Diana P Lo, Ian R Harris, Sicco H Popma, David H Sachs, and Christene A Huang*
Transplantation Biology Research Center, Massachusetts General Hospital, Boston, MA, United States
Stem Cell Internal Venture, Centocor R&D, Inc., Radnor, PA, United States
* Corresponding author; email: huangc{at}helix.mgh.harvard.edu.
Umbilical cord tissue provides a unique source of cells with potential for tissue repair. Umbilical cord tissue derived cells (UTC) are MHC class I (MHCI) dull and negative for MHC class II (MHCII), but can be activated to increase MHCI and to express MHCII with IFN-
stimulation. Mesenchymal stem cells with similar characteristics have been inferred to be non-immunogenic; however, in most cases, immunogenicity was not directly assessed. Using UTC from Massachusetts General Hospital (MGH) MHC-defined miniature swine, we assessed immunogenicity across a full MHC barrier. Immunogenicity was assessed by in vitro assays including mixed lymphocyte reaction (MLR) and flow cytometry to detect serum allo-antibody. A single injection of MHC mismatched unactivated UTC did not induce a detectable immune response. When injected in an inflamed region, injected repeatedly in the same region or stimulated with IFN- prior to injection, UTC were immunogenic. As clinical cellular repair strategies may involve injection of allogeneic cells into inflamed regions of damaged tissue or repeated doses of cells to achieve the desired benefit, our results on the immunogenicity of these cells in these circumstances may have important implications for optimal success and functional improvement for this cellular treatment strategy for diseased tissues.
