CD8A and papilloma: To examine whether this response is sufficient to clear an established infection and thereby prevent subsequent papilloma formation, we expanded for adoptive transfer experiments a MusPV1 E6 a.a. 90–99 specific CD8 cytotoxic T cell line in vitro (S7 Fig) from the splenocytes of C57BL/6 mice previously vaccinated with CRT-mE6 DNA three times by in vivo electroporation.