An oligomeric Major Histocompatibility Complex (MHC) complex comprising at least two chimeric proteins, said chimeric proteins comprising a first section derived from an MHC peptide chain or a functional part thereof and a second section comprising an oligomerising domain derived from an oligomer-forming coiled-coil protein, said complex further comprising attaching means for selectively attaching said MHC complex to a target cell, wherein formation of the oligomeric MHC complex occurs by oligomerisation at the oligomerising domain of the chimeric proteins, and wherein at least two of the first sections are derived from the same MHC peptide chain. In one embodiment, the complex further includes peptide bound to the MHC portions of the complex in the groove formed by the MHC alpha1 and alpha2 domains for class I complexes or the MHC alpha1 and beta1 domains for class II complexes. Related processes for amplifying T-cells, chimeric proteins, vectors, recombinant expression cassettes, pharmaceutical compositions and processes for making pharmaceutical compositions are also disclosed.
