Detection of a virus-specific antigen on the surface of herpes simplex virus-transformed cells

Alterations in the cellular phenotype induced by herpes simplex viruses

Numerous studies have shown that herpes simplex virus types 1 and 2 (HSV-1, HSV-2) are able to transform the morphological phenotype of rodent cells. Unlike other DNA tumor viruses the transformed cells did not consistently retain or express a given set of viral genes. In fact, transformation could be obtained using fragments of viral DNA that did not wholly encode viral proteins. Of interest within the transforming fragments were sequences which could assume a secondary structure like that of insertion elements. The failure to detect viral DNA in transformed cells led to the hit-and-run hypothesis of HSV transformation. The mechanism by which HSV induces transformation is not understood. Various lines of investigation have shown that HSV is able to cause mutations--both point mutations and gene rearrangements. HSV is also able to induce gene amplification, particularly of sequences harboring an origin of replication such as SV40 or papillomaviruses. Other experiments have shown that HSV can activate the expression of endogenous type C retroviruses. More broadly, HSV has been shown to activate cellular transcription or to switch on the synthesis of host cell proteins not normally expressed in untransformed cells. The failure to detect viral DNA in a high proportion of human anogenital tumors made it difficult to implicate HSV in the etiology of those neoplasias, but it is consistent, however, with the observations on the mode of HSV transformation in vitro, and suggests that HSV could be involved in a multistage process of oncogenic transformation.

Human T-lymphocyte response in vitro to synthetic peptides of herpes simplex virus glycoprotein D

Immunization of mice with a synthetic peptide that corresponds to a murine antibody-defined immunodominant domain of herpes simplex virus (HSV) glycoprotein D (gD) induced neutralizing antibodies against HSV types 1 and 2 and protected animals against a lethal challenge with HSV type 2 (Dietzschold, B., Eisenberg, R., Ponce de Leon, M., Golub, E., Hudecz, F., Varicchio, A. & Cohen, G. (1984) J. Virol. 52, 431-435). We report here that human peripheral blood T cells from HSV-seropositive and -seronegative adult donors are activated by this synthetic peptide in vitro. Interleukin-2-dependent T-cell lines established from these cultures respond specifically to peptides containing residues 1-23 of HSV gD and to a panel of overlapping peptides within this domain. The T-cell proliferative response was maximal when the majority of interleukin-2-propagated T cells were of the helper phenotype and the peptides were at least 16 amino acids long. Peptides of 8 or 12 amino acids from the carboxyl terminus were nonstimulatory. Peptide-activated T-cell lines from sero-negative donors less than 11 years old could be established in vitro, but most cells were of the suppressor/cytotoxic phenotype and demonstrated no antigen-specificity when tested with the panel of synthetic peptides.

Small fragments of herpesvirus DNA with transforming activity contain insertion sequence-like structures

A 737-base-pair fragment of herpes simplex virus type 2 DNA with morphological-transforming ability was identified by transfecting into rodent cells deleted fragments of the left-hand end of the Bgl II N fragment region (map position 0.58-0.625), which were constructed in vitro. The transforming sequences lie within the coding region for a Mr 61,000 protein, but the fragment itself does not appear to specify a viral polypeptide. Contained within the transforming fragment are sequences that can be drawn as a stem-loop structure flanked by direct repeats, similar to an insertion sequence-like element. An insertion sequence-like structure was also found in a small fragment of human cytomegalovirus DNA that has transforming activity. Possible mechanisms of herpesvirus transformation are discussed.

Synthesis and processing of glycoprotein D of herpes simplex virus types 1 and 2 in an in vitro system

We carried out studies of in vitro translation and processing of glycoprotein D (gD) of herpes simplex virus types 1 and 2 by using mRNA from cells infected for 6 h and a reticulocyte lysate translation system. Polypeptides of 49,000 daltons were immunoprecipitated with anti-gD-1 sera. Each in vitro-synthesized molecule had the same methionine tryptic peptide profile as the respective in vivo precursors, pgD-1 and pgD-2. In addition, the polypeptides synthesized in vitro were larger than the corresponding molecules synthesized in the presence of tunicamycin. This suggested that each of the gD polypeptides synthesized in vitro contained a transient N-terminal signal sequence. When the translation mixture was supplemented with pancreatic microsomes, each of the gD polypeptides was converted cotranslationally to a larger-molecular-weight form. Processing involved addition of three N-asparagine-linked oligosaccharides and removal of the signal peptide. When trypsin was added after in vitro processing, a polypeptide which was 3,000 daltons smaller than the in vitro-modified form of gD was immunoprecipitated. Experiments with endo-beta-N-acetylglucosaminidase H showed that this polypeptide still contained the three N-asparagine-linked oligosaccharides. Two monoclonal antibodies, 57S (group V) and 17O (group VII), were used to further orient gD in microsomes. The group V determinant was located in the trypsin-sensitive 3,000-dalton fragment, and the group VII determinant was located in the portion of gD which was protected from trypsin. We concluded that gD is oriented with the three glycosylation sites inside the vesicles and that 3,000 daltons containing the group V determinant are located outside. Immunofluorescence studies indicated that the group V determinant of gD is inside the plasma membrane of herpes simplex virus-infected cells and that the group VII determinant is outside. This cellular orientation is consistent with predictions based on the in vitro experiments.

The oncogenic potential of herpes simplex viruses: evidence for a 'hit-and-run' mechanism

Experiments to determine the mechanism of transformation of herpes simplex virus (HSV) have identified fragments of viral DNA which are able to initiate transformation. No set of viral genes seems to be consistently retained or expressed in the transformed cells or in human cervical tumours, suggesting that viral DNA is not needed to maintain the transformed phenotype. In fact there is no conclusive evidence that initiation of neoplasia is mediated by a viral protein. Here we revisit the 'hit-and-run' hypothesis and its implications for HSV-induced tumorigenicity.

Herpesvirus-specific RNA and protein in carcinoma of the uterine cervix

Cloned probes of herpes simplex virus type 2 DNA were used in cytological hybridization experiments to detect herpesvirus RNA transcripts in the neoplastic cells of tumors of the uterine cervix. Virus-specific RNA was shown to represent transcription of limited regions of the genome, of which one is known to code for a DNA-binding protein that can be found by immunoperoxidase staining in the neoplastic cells of these tumors and has also been detected in cells transformed in vitro by this virus.

Identification of proteins encoded by a fragment of herpes simplex virus type 2 DNA that has transforming activity

Cloned BglII fragment N (map units 0.58 to 0.625) of herpes simplex virus type 2 DNA has been shown to transform rodent cells to an oncogenic phenotype (Galloway and McDougall, J. Virol. 38: 749-760, 1981). RNA homologous to this fragment directs the synthesis of five polypeptides in a cell-free translation system. The approximate molecular weights of these proteins are 140,000, 61,000, 56,000, 35,000, and 23,500. The 35,000-dalton protein is the major species late in infection and is the only species detected before the onset of viral DNA replication. The arrangement of the sequences encoding these proteins along the herpes simplex virus type 2 genome was determined by hybridization of the RNA to cloned PstI fragment of BglII-N and to single-stranded DNA segments cloned into M13mp7. Both the hybridization experiments and immunoprecipitation with monoclonal antibodies suggested that the 140,000- and 35,000-dalton proteins are at least partially colinear and share antigenic determinants.

Detection of herpes simplex virus type 2 glycoproteins expressed in virus-transformed rat cells

Rat embryo fibroblasts transformed by herpes simplex virus type 2 (HSV-2) were assayed for the expression of certain virus-specific glycoproteins on the surface membranes. Monospecific antisera to HSV-2-specific glycoproteins, designated gAgB, gC, and gX, were used in membrane immunofluorescence studies with HSV-2-transformed cell lines tREF-G-1, tREF-G-2, and a tumor-derived rat fibrosarcoma cells line produced in syngeneic rats inoculated with tREF-G-1 cells. Analysis of the three HSV-2-transformed cell lines showed that antisera to the gAgB and gX glycoproteins were reactive with these cells. In contrast, no significant reactivity was observed when anti-gC serum was reacted with the HSV-2-transformed cell lines. All three antiglycoprotein sera reacted positively with rat cells productively infected with HSV-2. Additionally, the HSV-2-transformed and tumor-derived cell lines showed positive internal immunofluorescence after reaction with antiserum to an early, nonstructural viral protein designated VP143 (molecular weight, 143,000). Infectivity of HSV-2 in standard plaque assays was neutralized by hyperimmune rat antisera to tREF-G-2 or rat fibrosarcoma cells and to HSV-2 virions and by sera from rats bearing the fibrosarcoma. Adsorption of rat-anti-HSV-2 serum with tREF-G-2 or rat fibrosarcoma cells reduced neutralizing activity to 10 and 12%, respectively, compared with 90% neutralization by antiserum adsorbed with nontransformed rat embryo fibroblast cells and 100% neutralization with unadsorbed antiserum. In summary, HSV-2-transformed rat cells retained and expressed genetic information necessary for the production of HSV-2 glycoproteins and a nonstructural protein after high passage in tissue culture or in the syngeneic host.

Expression of herpes simplex virus type-common surface antigens in clonal cells of an HSV type 2-transformed line: effect of adriamycin

The expression of herpes simplex virus (HSV) type-common surface antigens (CSA) in a representative cell clone (155-4-03) of hamster cell line 155-4 transformed by HSV type 2 was enhanced by treatment with inhibitors of RNA synthesis [adriamycin (ADM) and daunomycin] but not with inhibitors of DNA synthesis (2-iododeoxyuridine, bleomycin, mitomycin C and cytosine arabinoside), although all these drugs decreased the number of viable cells to a similar extent. ADM-enhanced CSA expression in the clone was inhibited by puromycin and 2-deoxy-d-glucose, suggesting that the enhanced expression required both protein synthesis and glycosylation. This enhanced expression was sensitive to protease inhibitors (antipain and p-nitrophenyl-p'-guanidinobenzoate) and procaine, which is known to inhibit trypsin action and the organization of cell membrane-associated cytoskeletal elements (microfilaments and microtubules). Furthermore, low concentrations of ADM (0.1 microgram/ml) and actinomycin D (0.5 microgram/ml) enhanced CSA expression additively, but the most effective concentrations of ADM (0.25 microgram/ml) and actinomycin D (2 microgram/ml) did not. These findings indicated that the two drugs enhance CSA expression in the clone by a common mechanism.

Mechanisms of expression of herpes simplex virus-common surface antigens in clonal cells of a herpes simplex virus type 2-transformed line

Rabbit antiserum hyperimmune to herpes simplex virus type 1 was used to study the expression of herpes simplex virus type-common surface antigens (CSA) by indirect immunofluorescence tests in three representative cell clones isolated from a herpes simplex virus type 2-transformed hamster line, 155-4. These three clones showed different phenotypes with respect to CSA expression: (i) a CSA-positive type (clone (155-4-213), in which the antigens increased soon (5 h) after seeding at 37 degrees C, but not after treatment with actinomycin D; (ii) a CSA-inducible type (clone 155-4-03), in which the antigens increased after treatment with actinomycin D (2 micrograms/ml) for 20 h, but not after seeding only; and (iii) a CSA-negative type (clone 155-4-16), in which the antigens did not increase after seeding or after actinomycin D treatment. CSA expression in the CSA-positive type was inhibited by 2-deoxy-D-glucose, but not by puromycin, suggesting that the expression required glycosylation, but not active protein synthesis. CSA expression in this type was insensitive to the protease inhibitors antipain and p-nitrophenyl-p'-guanidinobenzoate. On the other hand, actinomycin D-induced CSA expression in the CSA-inducible type was inhibited by both 2-deoxy-D-glucose and puromycin, suggesting that the induced expression required both glycosylation and protein synthesis. CSA expression induced in this type was sensitive to the two protease inhibitors at concentrations having little effect on overall cellular metabolism or cell viability. These results indicate that CSA expressions in the CSA-positive type and the CSA-inducible type are enhanced by different mechanisms.

Synthesis and processing of glycoproteins gD and gC of herpes simplex virus type 1

Herpes simplex virus type 1 (HSV-1) contains five glycoproteins, designated gA, gB, gC, gD, and gE. The present studies focused on the synthesis and processing of two of these, gC and gD. By using monoprecipitin antibody to gC, we demonstrated an antigenic and structural relationship between the precursor, pgC(110), and the product, gC(130). Tryptic peptide analysis showed that pgC and gC shared methionine peptides and that these molecules had the same fingerprint pattern as that of gC(130) extracted from the purified virion. These results suggested that post-translational processing of gC involved no major changes in methionine-containing tryptic peptides or in the cleavage sites required to generate those peptides. The syntheses of gC and gD were compared. We found that the glycoproteins were synthesized starting at different times in the infectious cycle; pgD was detected by 2 h postinfection, whereas pgC was first detected at 4 to 6 h postinfection. Both precursor molecules, pgC(110) and pgD(52), are basic glycopolypeptides, and in both cases processing involved changes in molecular weight and charge. These changes were detected by two-dimensional gel electrophoresis. Both glycoproteins exhibited heterogeneity, displayed as a series of spots (6 for gD and 15 to 20 for gC) of increasing negative charge and molecular weight. Neuraminidase treatment decreased the size, number, and acidic charge of the spots, suggesting that processing was due in part, but not entirely, to addition of sialic acid to pgD and pgC.

Genetic retrieval of viral genome sequences from herpes simplex virus transformed cells

Oncogenic transformation of cultured cells by inactivated herpes simplex virus (HSV) types 1 and 2 has been demonstrated. Expression of HSV information in these transformed cells has been shown by immunofluorescence studies, detection of HSV neutralizing antibody in sera from tumour-bearing animals and by hybridization of HSV-specific RNA. Molecular hybridization studies of DNA from HSV-2 transformed hamster cells have detected up to 40% of the HSV genome present in several copies. Complementation of three HSV-2 temperature-sensitive mutants when superinfecting the RE1 rat embryo cell line (transformed by the HSV-2 temperature-sensitive mutant ts1) suggests that resident viral genes can be expressed. Brown et al. used a similar approach to detect HSV information latent in human ganglia. We report here retrieval of intertypic HSV recombinants from HSV transformed cells after superinfection with ts mutants of the alternative serotype of HSV. Restriction enzyme analysis which clearly differentiates between HSV-1 and HSV-2 DNA has demonstrated the isolation of recombinants spanning the genome and of virus indistinguishable from the original transforming virus.

Structural analysis of the capsid polypeptides of herpes simplex virus types 1 and 2

Capsids of herpes simplex virus (HSV) types 1 and 2 contain seven polypeptides ranging in molecular weight from 154,000 to 12,000 (termed NC-1 through NC-7 in order of descending molecular weight). Antibodies prepared to HSV-1 capsid polypeptides isolated from sodium dodecyl sulfate-polyacrylamide gels reacted in an immunofluorescence assay against HSV-1-infected KB cells. Three of the antibodies (anti-NC-1, anti-NC-2, and anti-NC-3,4) also reacted with HSV-2-infected cells. Tryptic peptide analysis showed that each of the HSV-1 capsid polypeptides had a unique methionine peptide profile, and none appeared to be derived from the major capsid polypeptide. Comparative peptide analysis of HSV-1 and HSV-2 showed that one polypeptide (NC-7, 12,000 molecular weight) had an identical methionine peptide profile and a very similar arginine peptide profile in both virus types. The arginine peptide profile of NC-7 of HSV-1 was very different from the arginine profile of KB histone H4. Although there were certain intertypic similarities in the methionine peptide profiles of the other capsid components especially in NC-1 (the major capsid protein), there was no case where the tryptic peptides were identical in the two virus types.

Herpes simplex virus glycoproteins: isolation of mutants resistant to immune cytolysis

Immune cytolysis mediated by antibody and complement is directed against components of the major herpes simplex virus (HSV) glycoprotein complex (molecular weight, 115,000 to 130,000), comprised of gA, gB, and gC, and against glycoprotein gD-all present on the surfaces of infected cells. Tests with a temperature-sensitive (ts) mutant of HSV-1 (tsA1) defective in glycoprotein synthesis at the nonpermissive temperature (39 degrees C) demonstrated that over 90% of mutant-infected cells maintained at 39 degrees C and treated with antibody and complement were not lysed, presumably due to the absence of viral glycoproteins on the surface of infected cells at this temperature. Furthermore, a small number of tsA1-infected cells could be detected among a large excess of wild-type virus-infected cells by virtue of their failure to be lysed at 39 degrees C by antibody and complement. Making use of the involvement of viral glycoproteins in immune cytolysis and the ability of cells infected with glycoprotein-defective mutants to escape cytolysis, we sought mutants defective in the expression of individual viral glycoproteins. For this purpose, antisera directed against the VP123 complex and against the gC and combined gA and gB glycoprotein subcomponents of this complex were first tested for their ability to lyse wild-type virus-infected cells in the presence of complement. Wild-type virus-infected cells were lysed after treatment with each of the three antisera, demonstrating that the gC glycoprotein and the combined gA and gB glycoproteins can act as targets in the immune cytolysis reaction. Next, these antisera were used to select for mutants which were resistant to immune cytolysis. Cells infected with wild-type virus which had been mutagenized with 2-aminopurine and incubated at 39 degrees C were treated with one of the three types of antisera (anti-VP123 complex, anti-gC, or anti-gAgB) and lysed by the addition of complement. Cells which survived immune cytolysis were plated, and virus in the resulting plaques was isolated. Plaque isolates were tested for temperature sensitivity of growth and altered cytopathic effects in cell culture at 34 degrees C (the permissive temperature) and 39 degrees C. A total of 73 mutants was isolated in this manner. Selection with glycoprotein-specific antisera resulted in a 2- to 16-fold enrichment for mutants compared with "mock" -selected mutants using normal rabbit serum. Phenotypically, 24 mutants were temperature sensitive for growth, 27 were partially temperature sensitive, and 22 were not temperature sensitive but exhibited markedly altered cytopathic effects at both permissive and nonpermissive temperatures. Nine mutants of each phenotype (temperature sensitive, partially temperature sensitive, and non-temperature sensitive) were selected at random for confirmatory immune cytolysis tests with the antisera used in their selection. Cells infected with eight of the nine mutants were shown to be significantly more resistant to immune cytolysis at the nonpermissive temperature than were the mock-selected mutants or the wild-type virus from which they were derived.

Effect of actinomycin D on the expression of herpes simplex virus-common surface antigen in cells transformed by herpes simplex virus type 2

Using rabbit antiserum hyperimmune to herpes simplex virus (HSV) type 1, the expression of HSV-common surface antigen(s) was studied by indirect immunofluorescence tests in cells transformed by HSV type 2 and in derived tumor cells. The following results were obtained. (i) Antiserum to HSV type 1 reacted specifically with surface antigen present on the plasma membrane of both HSV type 2-infected and HSV type 2-transformed hamster cells. (ii) The expression of this antigen was enhanced in the absence of active protein synthesis in transformed cells, but not in tumor cells, after culture for 3 to 5 h at 37 degrees C. (iii) This enhancement of expression was maintained for 20 h in the presence of actinomycin D, but this prolonged expression required active protein synthesis. (iv) The enhancing effect observed in the presence of actinomycin D continued for some time after removal of the drug, for example, for 20 h after 5 h of treatment with 2 microgram/ml of actinomycin D per ml. Actinomycin D had no detectable effect on antigen expression in tumor cells. (v) The protease inhibitor antipain inhibited the actinomycin D-enhanced expression without causing significant cell damage but did not modify the transient enhanced expression of antigen when cells were seeded in the absence of actinomycin D. These results indicate that in transformed cells antigen expression can be enhanced in at least two ways.

Type-common CP-1 antigen of herpes simplex virus is associated with a 59,000-molecular-weight envelope glycoprotein

The CP-1 antigen of herpes simplex virus type 1 (HSV-1) is a glycoprotein found in the soluble portion of infected cells, in detergent extracts of infected cell membranes, and in the envelope of purified virus. Antisera were prepared against a further purified form of CP-1 prepared from HSV soluble antigen mix; a glycoprotein, gp52, isolated from detergent-treated infected cells; and detergent extracts of purified virus. Each of the antisera reacted with CP-1 to give a single immunoprecipitin band of identity, and each antiserum neutralized the infectivity of HSV-1 and HSV-2. Our results suggested that the type-common determinants involved in the stimulation of neutralizing antibody resided on a 52,000-molecular-weight (52K) glycoprotein. The envelope of HSV contains several glycoproteins: one component at 59K and a complex of two or three components at 130K, none of which corresponds in molecular weight to gp52. Using the antisera as immunological probes, we performed pulse-chase experiments with [(35)S]methionine-labeled HSV-1-infected cells and followed the disposition of the glycoproteins during the infectious cycle. Each antiserum immunoprecipitated a (35)S-labeled 52K protein from lysates of cells pulse-labeled at 5 h after infection. By 10 h, the label was chased into a 59K protein also precipitable by each of the three antisera. The results suggest that gp52 is a precursor of gp59 and that the latter corresponds in molecular weight to one of the major glycoproteins of the virion envelope.

Viruses and renal carcinoma of Rana pipiens. XV. The presence of virus-associated membrane antigen(s) on Lucké tumor cells

Virus-specific antigens were detected in Lucké tumor cells by indirect immunofluorescence using antiserum prepared against Lucké herpesvirus. Intracellular fluorescence, both cytoplasmic and nuclear, was observed only in acetone:methanol-fixed tumor cells that contained herpesvirus detected by electron microscopy. The number of positive cells correlated well with the number of cells containing virus. In contrast, both virus-containing and virus-free cells exhibited membrane fluorescence when viable unfixed tumor cells were tested. A striking reduction in the number of membrane fluorescent cells was observed with an increase in the length of time that tumor cells were in primary culture. No reaction was observed with a variety of normal R. pipiens cells. Absorption of the antiserum with normal frog kidney tissue had no effect on the number of positive cells whereas absorption with virus-free tumor reduced the reaction; absorption with virus-containing tumor eliminated it. These findings provide the first demonstration that the Lucké herpesvirus genome resident in virus-free tumor cells expresses a virus-associated membrane antigen(s).

Expression of an early, nonstructural antigen of herpes simplex virus in cell transformed in vitro by herpes simplex virus

Hyperimmune rabbit antiserum to an early, nonstructural herpes simplex virus type 2 (HSV-2)-induced polypeptide (VP143) reacted in immunofluorescence tests with a variety of cell lines transformed by HSV-2. Cytoplasmic fluorescence was observed in 10 to 50% of HSV-2-transformed cells, whereas no fluorescence was observed in cells transformed by other oncogenic DNA viruses or by a chemical carcinogen. VP143-specific reactivity could be absorbed from anti-VP143 serum with HSV-2-transformed cells but not with cells transformed by other agents. When HSV-2-transformed cells were synchronized in mitosis and examined at various times postmitosis for VP143-specific fluorescence, the expression of VP143 was shown to be cell cycle dependent.

Identification of virion polypeptides in hamster cells transformed by herpes simplex virus type 1

Ten polypeptides were detected on the surface of the virion of herpes simplex virus type 1. Of these ten polypeptides, three were detected in hamster cells transformed by herpes simplex type 1.

Herpes simplex virus gene expression in transformed cells. I. Regulation of the viral thymidine kinase gene in transformed L cells by products of superinfecting virus

In this paper we show that the expression of the herpes simplex virus type 1 (HSV-1) gene for thymidine kinase (tk) in HSV-transformed cells is subject to regulation by two viral products synthesized during productive infection of these cells with a tk- mutant of HSV-1. The cell line used in this study is a derivative of tk-deficient mouse L cells that, after exposure to UV-inactivated HSV-1, had acquired the HSV-1 gene for tk (which we term a resident viral gene) and consequently expressed the tk+ phenotype (LVtk+ cells). Productive infection of these cells with HSV-1(tk-) at appropriate multiplicities caused significant enhancement of the viral tk activity. The results of several experiments allow us to conclude that this enhancement was due to increased synthesis of tk specified by the HSV-1 gene resident in the LVtk+ cells and that a specific protein made early after infection with HSV-1(tk-) mediated the enhancement, probably by increasing the production of mRNA from the viral tk gene resident in the LVtk+ cells. Our data also indicate that another HSV-1(tk-) product acted to turn off tk synthesis. The finding that tk activity continued to increase for a longer time after infection of the LVtk+ cells at 2 PFU/cell than after infection at higher multiplicities suggested the synthesis of a product which inhibited tk synthesis and whose concentration reached critical levels earlier at higher multiplicities of infection. Inhibition of DNA synthesis after infection, a treatment that depresses the synthesis of late viral proteins, prolonged the synthesis of tk in LVtk+ cells infected at either 2 or 5 PFU/cell. Infection of the LVtk+ cells with HSV-2(tk-) resulted in only small increases in tk activity, indicating some type specificity in recognition of viral products that can modify the expression of the HSV-1 tk gene resident in these cells.

Cross-reacting herpes simplex virus antigens in hamster and mouse cells transformed by ultraviolet light-inactivated herpes simplex virus type 2

Murine and hamster cell lines, each transformed with a different strain of herpes simplex virus (HSV), were examined for cross-reacting antigens by in vitro and in vivo assays. A comparative study by the indirect immunofluorescence technique detected common cross-reacting viral antigens. Cytoplasmic fluorescence patterns were observed in the 333-8-9 hamster line, the H238 murine line, and the H238 clonal lines; these patterns were identical to the fluorescence pattern of HSV -2-infected controls when reacted with HSV antiserum. Tumor rejection studies in the BALB/c host indicated that each cell line provided immunity against a tumorigenic challenge of transformed mouse cells. The H238 clone EC1 3 provided a 53% immunity against itself at an inoculum of 10(6); the 333-8-9 line supported a 26% immunity. These data demonstrate a common HSV antigenicity between the murine and hamster transformed lines and further indicate that the HSV genome is involved in transformation.