[Interactions of Shope papilloma virus with SV40 in adult domestic rabbit cell lines derived from normal skin or from Shope papilloma virus infected skin (author's transl)].

Three cell lines from adult domestic rabbit are infected with SV40: LP 17 and LP 45 derived from normal skin and LP 42 PS derived from skin infected for 24 h with Shope papilloma virus. The fibroblastic morphology of the cultures is not changed. SV40 is not recovered and T antigen is only detected in LP 42 PS cell line after 29 passages. To know if Shope papilloma virus facilitates penetration of SV40, cultures of LP 45 are first infected with Shope papilloma virus for 2 h and for 24 h, then superinfected with SV40. There is no cellular alteration, and T antigen induced by SV40 is only detected in cells pretreated for 24 h with Shope papilloma virus, after 20 passages. When cultures LP 45 are infected with Shope papilloma virus neutralized with a high titer antiserum and superinfected with SV40, T antigen is not detected. Superinfected cells containing specific SV40 T antigen do not induce tumors either in new born hamsters or in rabbits but they are able to grow in colonies in soft agar. LP 42 PS cell line and LP 45 cells infected with Shope papilloma virus for 24 h containe Shope papilloma virus genome which is able to modify the permissivity of rabbit cells to SV40.