The present invention relates to a novel type of human recombinant antibody-like molecules useful in the treatment of i.e. multiple myeloma. Thesemolecules, called Vaccibodies, bind APC and are able to trigger both T celland B cell immune response. Moreover, Vaccibodies bind divalently to APC topromote a more efficient initiation of an immune response. Hence, a majorpurpose of the present invention is to induce a strong immune response torender adjuvants redundant. Vaccibodies comprise a dimer of a monomeric unitthat consists of a targeting unit with specificity for a surface molecule onAPC, connected through a hinge region and a C.gamma.3 domain to a antigenicunit in the COOH-terminal end the latter being of e.g. B cell lymphoma ormyeloma origin (Fig 1), although any origin is possible due to the cassettecloning system in the expression vector. The said molecule is capable ofinducing an immune response against multiple myeloma, but extension to ageneral vaccination strategy for any polypeptid should be feasible. Thepresent invention also relates to a DNA sequence coding for this recombinantantibody based molecule, to expression vectors comprising these DNA sequences,cell lines comprising said expression vectors, to treatment of mammalspreferentially by immunization by means of Vaccibody DNA, Vaccibody RNA, orVaccibody protein, and finally to pharmaceuticals and a kit comprising thesaid molecules.
