Directing CMV-specific T cells to CLL cells by a 2-step antibody targeting system. (1) Anti-CD20 construct and HLA class I molecules presenting viral peptide will be connected by strong streptavidin-biotin interaction, forming a targeted complex (TC). (2) Anti-CD20 will bind to CD20-expressing cells (like CLL), and HLA/CMV peptide will bind to specific T-cell receptors. CMV-specific T cells will be activated, resulting in specific killing of target cells.