The Incorporation of Sv40 Genetic Material Into Adenovirus 7 as Measured by Intranuclear Synthesis of Sv40 Tumor Antigen

Abstract

The surprising finding of Huebner et al.1 that tumors developing in hamsters after inoculation with adenovirus 7 contain the complement-fixing cellular antigen2 of SV40 transformed cells suggested that preparations of adenovirus 7 should -be studied for ability to induce similar antigens in cells growing in culture. Recent observations using the immunofluorescence technique had confirmed that cells transfotmed by SV40 contain a new cellular antigen; this antigen appears to be synthesized in the nucleus and is present in all cells of cultures derived from SV40-transformed systems.3' 4 These sensitive techniques have made it possible to detect the tumor antigens even when they are synthesized in relatively few cells in the culture. The same techniques have been used to demonstrate that the SV40 tumor antigens occur not only in virus-free transformed cells but are also synthesized in cells infected with SV40 prior to the appearance of the virus antigens.5 6 This report will document the finding that preparations of adenovirus 7 grown in monkey cells and free of infectious SV40 can induce the synthesis of a new intranuclear antigen unrelated to adenovirus in a wide variety of cells. This antigen is similar to or identical with the tumor antigens induced by SV40 virus. These results suggest the incorporation and transmission of a portion of the SV40 genome by the unrelated adenovirus.Materials and Methods.-Viruses: The L. L. strain of adenovirus 7 used in these studies, kindly made available by Wyeth Laboratories, was originally isolated and passed serially in primary rhesus kidney cells. Stocks of the virus were subsequently found to be contaminated with SV40 and were therefore treated with SV40 antiserum and passed twice in primary green monkey kidney (GMK) cells in the presence of the antiserum. The virus was then passed 4 times in the absence of antiserum in GMK cells; large volumes of each virus yield were tested and found to be free of infectious SV40. This virus stock was designated E46. A stock of virus consisting of several liters was prepared by passing E46 in GMK, and the harvest was designated SP2. Samples of lots E46 and SP2 were kindly supplied by Dr. B. A. Rubin of Wyeth Laboratories. Repeated attempts to isolate SV40 from E46 and SP2 have been unsuccessful. Complement fixation tests with SV40 antiserum have also failed to detect the presence of SV40 antigen. A fresh isolate of adenovirus 7 from a fatal human case7 passed only in human embryonic kidney (HEK) cells was also employed.Cells: The various cells utilized were grown in Eagle's basal medium fortified by varying concentrations of calf serum ranging from 2 to 10%; GMK cells were grown in Melnick's medium.Immunofluorescence tests: The cells were trypsinized and grown on 15-mm cover glasses in 60-mm plastic Petri dishes in 5% CO2 at 37°C. When monolayers had formed, 0.1 ml of virus inoculum was added per cover glass, adsorption allowed to occur for 1 hr at 37°C, and 5 ml of maintenance fluid added per Petri dish. The cultures were reincubated at 37...

Reactivation of herpes simplex virus type 2 from a quiescent state by human cytomegalovirus.

“…The interaction among these harbored viruses may be crucial to the pathological state and may be of particular significance with regard to latent virus infection. Indeed, the replication of numerous viruses has been shown to be affected by the presence of coinfecting viruses such as human adenoviruses and simian virus 40 (12,13) or simian adenovirus SV15 (14), Marek's disease virus and avian leukosis virus (15), and Moloney sarcoma and leukemia viruses (16). To rescue potentially defective HSV in neurons, Brown and coworkers (17) To establish latent infection of HEL cells with HSV-2, we followed previously described protocols (18,19).…”

Adenovirus: from foe to friend

“…The explanation for these failures became evident when it was found that the insidious SV40 and/or respective antigens originated from hybrid viruses carrying SV40 and HAdV DNA [77][78][79]. Ironically, it was the selection for these hybrid viruses that allowed the production of the vaccine material in the first place.…”

Genetic Evidence for a Temperature-Sensitive Lesion in the Adenovirus 7 Region of the PARA Genome

“…The salient properties of the viruses employed in this study are summarized in table 1. The SV40-Ad 7 hybrid virus (E46 + , stock SP2, designated PARA-Ad 7) has been described in detail [2]. 2 additional passages of this virus were carried out in GMK cells prior to this study.…”

“…Cells infected with PARA synthesize SV40 tumor (T), U and trans plantation antigens, but no SV40 viral (V) antigen [2][3][4][5]. PARA-Ad 7 can induce SV40-typc tumors in vivo; it is highly oncogenic, whereas the parental Ad 7 is very weakly oncogenic in newborn hamsters [6,7], PARA also ex presses the SV40 function of enhancing human adenovirus replication in cells of simian origin [8].…”