Complementation of ts mutants by a herpes simplex virus ts-transformed cell line

Abstract

THE first evidence that human herpesvirus could transform cultured cells was provided by Munyon et al.¹ who showed that the thymidine kinase activity of herpes simplex could be expressed in mouse-derived L cells lacking this enzyme (LTK⁻ cells). The oncogenic potential of human herpes virus was demonstrated by Duff and Rapp^2,3 who showed that hamster embryo cells transformed by ultraviolet-inactivated herpes simplex virus (HSV) were oncogenic in newborn hamsters. Further evidence of HSV transformation has been described in cultured human, rat and mouse cells^4–7. The exact role played by HSV in transformation of primary embryo cells and the amount of information (if any) required to maintain the transformed state is not known. Temperature-sensitive (ts) mutants of HSV-2, HG 52 have been shown to complement each other⁸. These ts mutants may be used in complementation tests together with rat embryo cells transformed by another ts mutant to demonstrate the expression of herpes information in the transformed line. We report here evidence of such complementation between an HSV-2 ts mutant-transformed rat embryo line and three superinfecting HSV-2 ts mutants. This complementation suggests that this oncogenically transformedline can express herpes information sufficient to complement at least three genes.