Transformation of Cultured Mammalian Cells by Viable Herpes Simplex Virus Subtypes 1 and 2

Abstract

A continuous line of rodent cells carrying the genome of the Rous sarcoma virus was stably transformed by exposure to viable herpes simplex virus of either subtype 1 or 2. Transformation was accompanied by alteration of morphology, growth characteristics, acquisition of a thymidine kinase activity (EC 2.7.1.21) resembling the corresponding specific activity of the enzyme in the herpes simplex virus, and capacity to express continuously some antigens specific for herpes simplex virus.A considerable body of evidence implicates herpesvirus as the etiological agent of certain forms of cancer (1, 2). Of particular current interest is the possible link between human cervical carcinoma and herpes simplex virus (HSV) subtype 2, but the evidence to date is largely circumstantial. Cells transformed in culture by HSV might provide a valuable system to explore the oncogenic potential of this virus. Biochemical transformation of thymidine-kinase-deficient (TK-) mouse cells to the thymidine-kinase-positive phenotype has in fact been achieved using ultra-violet inactivated HSV (3). The molecular basis of the mode of selection of transformants and of the acquisition of new kinase function has yet to be rigorously established, although the available evidence is consistent with the conclusion that the cells stably inherit the capacity to synthesize thymidine kinase (TK) that is specific for HSV.To determine which biochemical properties of HSV most closely reflect its putative oncogenic function, it would be useful to have a cell system which could be transformed by viable virus or conditional lethal mutants thereof. We describe here the transformation of cells by HSV, subtype 1 Antiserum to rabbit-y-globulin was prepared by inoculating goats with purified rabbit-y-globulin (Miles Laboratories, St. Louis, Mo.). Goats were inoculated twice intradermally 220

Interaction of Herpes Simplex Virus Type 1 with Rous Sarcoma Virus-Transformed Rat Cells [XC and R(B77) cell lines]

“…In rat cells transformed by RSV [XC and R(B77) cell lines], the oncornavirus genetic information is integrated into the cellular DNA without expression [1,7] but in an inducible state [8]. Studies on the infection of XC cells with HSV-1 and HSV-2 demonstrated that the herpesviruses failed to replicate in these cells although pseudorabies virus produced virus progeny [4,5]. This finding, as well as the observation of Docherty ei al.…”

“…In XC cells no virus particles entered the cytoplasm and therefore were sensitive to trypsin, while in BSC-1 cells 50% of the particles entered the cytoplasm and were not removed by trypsin, as shown previously [9]. Failure of HSV-1 to penetrate into the cyto plasm of XC cells provides an explanation as to why these cells are nonpermissive to infection with HSV [2][3][4][5].…”

“…Docherty et al [2] and Campbell et al [3] reported that the herpesvirus particles attached to the XC cells but did not induce the synthesis of either virus-specified proteins or viral DNA. On the other hand, G arfinkle and McAuslan [4,5] suggested that there was a limited synthesis of viral DNA in herpesvirus-infected XC cells, followed by the synthesis of some viral antigens. The present study deals with the interaction of HSV-1 with XC cells.…”

Expression of Varicella-Zoster Virus-related Antigens in Biochemically Transformed Cells

“…Viral thymidine kinase (tk) is induced in cells by herpesviruses, and that of herpes simplex virus (HSV) has been studied extensively (Ogino et al, 1973;Garfinkel & McAuslan, 1974;Honess & Watson, 1977). Munyon et al (1971) have shown that L cells lacking thymidine kinase (tk-) can be biochemically transformed to a tk-positive phenotype (Ltk ÷) by infecting them with u.v.-irradiated HSV.…”

Morphological Transformation of Rat Embryonic Fibroblasts by Abortive Herpes Simplex Virus Infection: Increased Transformation Rate Correlated to a Defective Viral Genotype

“…UV-irradiated HSV [1][2][3][4], photodynamically inactivated HSV [5,6], temperature-sensitive mutants of HSV [7,8], and modified cells [9] were used in previous transformation experiments. In all of these cases the HSV-infected 1 We kindly acknowledge the expert technical assistance of J ulia Herb and Barbara Stegmann.…”