Monocyte/macrophages as effector cells in cancer immunotherapy

Among the different strategies which have been developed for immunotherapy of cancer, adoptive immunotherapy uses leucocytes activated in vitro and reinfused into the patients. Five leucocytes subsets can be employed for this immunotherapy with activated autologous cells. Blood monocytes can be isolated in high purity and large numbers and under special culture conditions differentiated into macrophages for adoptive transfer. Once activated ex vivo, these cells display very high antibody dependent and independent specific cytotoxicity for tumour cells, are capable of phagocytosis of cancer cells and, as antigen presenting, cells are able to involve CTL in the anticancer response. As the understanding of this activation to cytotoxicity is only recent, the present paper first provides a literature review of the main points in the field. Our own results are then discussed in relation to the development of a clinical protocol for adoptive transfer of MAK (macrophage activated killer) cells, a therapeutic strategy having a pivotal role in the immunosurveillance of cancer.