Expression of herpes simplex virus common surface antigens and malignancy by clonal cells of a herpes simplex virus type 2-transformed line.
Herpes simplex virus (HSV) type common surface antigens (CSA) were examined by indirect immunofluorescence with rabbit antiserum to HSV type 1 in a clonal hamster cell line 155-4 transformed by HSV type 2. The tumor formation was examined in hamsters transplanted with various transformed and tumor cells. The examination of subclones derived from 1554-cell line gave the following results. (1) Thirty subclones were isolated and classified into three phenotypes as to CSA expression: (i) in CSA-positive type (20% of the clones isolated), the number of CSA-positive cells increased soon (5 hr) after seeding at 37 degree; (ii) in CSA-inducible type (33% of the clones), the number of CSA-positive cells increased after treatment with actinomycin D (ACT-D, 2 micrograms/ml), but not without ACT-D; (iii) CSA-negative type (47% of the clones), the number of CSA-positive cells did not increase after seeding or after ACT-D treatment. (2) In tumor cell lines derived from the parent line and from three representative clones, CSA expressions were similar to that by CSA-negative type. (3) Transformed cells expressing CSA after seeding or after ACT-D treatment formed tumors and metastases less efficiently than cells expressing little CSA in transplanted hamsters. (4) Tumor cell lines formed tumors and metastases more efficiently than transformed cells expressing little CSA in transplanted hamsters.