Potentiation of Murine Sarcoma Virus (Harvey) (Moloney) Oncogenicity in Lactic Dehydrogenase-Elevating Virus-Infected Mice

Summary

Adult Balb/c mice previously infected with LDV and subsequently challenged with H-MSV or M-MSV showed (i) increased tumor incidence, (ii) reduction in the incidence of tumor regression, (iii) increased incidence of death with tumor, and (iv) reduction of the median survival compared to H-MSV- or M-MSV-infected controls.

Extracts of tumor from mice inoculated with H-MSV alone were devoid of focus-forming virus when assayed on 3T3 FL cells while extracts of tumors from mice dually infected with LDV and H-MSV contained 10^{2, 3} FFU/ml of virus in the absence of “helper”virus and 103.0 FFU/ml in the presence of “helper”virus.

The mechanism by which LDV potentiate H-MSV and M-MSV oncogenicity in adult mice is discussed.