Susceptibility of parthenogenetic stem cells and their derivates to cytotoxic effector mechanisms

Parthenogenetic stem cells may provide an attractive new source in regenerative medicine. As their major histocompability complex (MHC) ist haploidentical, PSC-banks may offer ready access to MHC-matched allogeneic stem cells. In this doctoral thesis their immunological properties were examined. PSC were largely resistant to CTLs derived from T-cell-receptor transgenic OT-I mice. However, it was shown that as undifferentiated PSC lack MHC-class-I-molecules and present various activating ligands on their surface, they are readily recognized and killed by NK-cell mediated effector mechanisms. Once further differentiated, PSC grew more resistant as a decrease in activating ligands, e.g. Rae-1, CD 112 and CD155, was observed. This might prove beneficial in a transplantational setting as residues of potentially tumorigenic undifferentiated cells could be eliminated by the host's immune response.2017-04-0