Targeted immunotherapy of cancer: development of antibody-induced cellular immunity

Although immunotherapy of cancer encompasses a large variety of distinct protocols, virtually all therapeutic strategies require the enabling/training of the immune system to distinguish tumour tissue from healthy tissue. In the case of antibody-based therapies, specificity obviously arises from the selectivity of the antibodies for tumour antigens, and tumour cell death derives from either direct cytotoxicity of the antibody or antibody-dependent cellular cytotoxicity. However, even when both of the above killing mechanisms are simultaneously active, we suggest that antibody-based immunotherapies may fall far short of their full potential. In this editorial, we first summarize the mechanisms by which current antibody-based therapies mediate cancer cell removal, and then propose two strategies by which this class of immunotherapies might be further improved. These suggested improvements involve the decoration of tumour cell surfaces with foreign haptens against which an endogenous humoral immune response can be mounted and the recruitment of the cellular arm of the immune system in an antibody-dependent process.