IMMUNOLOGICAL RELATIONSHIPS OF SOME ONCOGENIC DNA VIRUSES .I. TRANSPLANTATION IMMUNITY STUDIES

Tumour transplantability in weanling hamsters was investigated for six different in vitro cell generation levels of SV40 induced hamster tumour cells. Transplantability varied from 23% at the 55th cell generation of tumour cells to 71% at the 53rd cell generation. No direct relationship was demonstrated between the percentage of hamsters developing tumours and the cell generation level. The incidence of tumours occurring in the first month after inoculation of tumour cells varied from 7% to 17% and was greatest in animals inoculated with the largest number of tumour cells. At six months, the incidence of tumours was reversed; 37 % of hamsters inoculated with 5000 tumour cells had developed tumours and 55% of the animals which received 1000 cells had tumours. Immunization of hamsters with various normal cell extracts before transplantation of SV40 tumour cells enhanced tumour development. Immunization of hamsters with adenovirus types 5, 12 and 31, CELO virus and human wart virus did not induce transplant immunity against SV40 virus induced tumour cells: transplantation immunity was only found in hamsters immunized with SV40 virus. © 1969 Springer-Verlag.