Antitumor activity of MV-NIS or MV-NIS infected MSC in athymic mice passively immunized with human measles immune sera. (A) Bioluminescent and SPECT-CT imaging show rapid co-localization of Tc-99 m-pertechnetate loaded MV-NIS infected MSC (MSC-NIS) with luciferase positive SKOV3ip.1 tumors. (B) Mice with SKOV3ip.1 tumors were passively immunized with measles immune human sera and given 105 TCID50 MV-NIS or 105 MV-NIS infected hMSC at 7 days post-tumor implantation. RT = MSC were given 20 Gy radiation immediately before MV-NIS infection. F/T = Frozen stock of MV infected MSC was thawed, washed and used immediately. Actively growing = MSC were in log phase of expansion prior to MV-NIS infection. (C) p values comparing the survival curves of the respective groups are indicated (Log rank test, Mantel Cox).