| abstract |
The present invention relates to a vector comprising a first nucleotide sequence S1 encoding protein Z1, a second nucleotide sequence S2 encoding protein Z2, a third nucleotide sequence S3 encoding protein Y1, a fourth nucleotide sequence S4 encoding protein Y2 wherein Z1 and Z2 form a first dimer, Y1 and Y2 form a second dimer, and wherein the first dimer Z1Z2 is constitutively different from the second dimer Y1Y2. |