Comparative studies of transformed hamster cells by Herpesvirus hominis types 1 and 2

Hamster embryo cells transformed by Herpesvirus Type 2 (HSV-2) virus (two separate cell lines) and by HSV-1 virus (one cell line) were inoculated into hamsters. The morphological appearance of tumours was studied by both light and electron microscopy, and the results compared to similar studies of tumours induced by SV40 virus. The tumours were also tested for immunogenicity, and for susceptibility to contact suppression with BCG. The results indicated that the tumours induced by inoculation of HSV-transformed cells were distinct from those of other DNA viruses; that the two cell lines transformed by HSV-2 were very similar but distinct from the cell line transformed by HSV-1; that all 3 HSV tumour cell lines were weakly immunogenic, and 2 were susceptible to contact inhibition with BCG. The relevance of the morphological and immunogenic properties of the animal tumour is discussed with relation to the possible importance of the findings to human malignant disease.