Growth of Newcastle Disease and Herpes Virus and Interferon Production in a Monkey-Mouse Hybrid Line

SUMMARY The mean yield of NDV is about 0.1 p.f.u./cell in MKS-B mouse kidney cells, 100 p.f.u./cell in CV-1 monkey kidney cells and 70 p.f.u./cell in MK-CV111 clone 4, a hybrid line arising from the fusion of MKS-B and CV-1. The mean yield of herpes is about 2 p.f.u. in MKS-B, and 160 p.f.u. in both CV-1 and in MK-CV111 clone 4. The u.v. sensitivity of the capacity of cells to support NDV multiplication is the same for CV-1 and MK-CV111 clone 4 cells, but much lower for MKS-B cells, indicating that NDV replicates using at least some monkey functions of these hybrid cells. NDV or Sindbis infected hybrids produce both mouse interferon (99%) and monkey interferon (1%), the molecular weights of which are the same as those of corresponding parental interferons.