The invention refers to a split superantigen, divided into two fragments that by itself do not exhibit biologic activity, only upon dimerization they regain T cell activity. Scope of the invention is a screening method for detection of effective split superantigen designs, where split superantigen fragments are fused with coiled-coil forming peptides. The present invention relates to the field of cancer immunology. Each split superantigen fragment is fused with antibody or other tumor antigen specific protein, therefore only upon the binding of split superantigen-antibody fusion proteins to the tumor antigen, split superatigen fragments comes to proximity and reconstitute into biologically active form that activates T-cell response.
