Immune control of neoplasia by adoptive transfer of macrophages: potentiality for antigen presentation and gene transfer.

Human macrophages could be differentiated from mononuclear precursors present in the blood circulation. After IFN-gamma activation, they became antitumoral and adhered to transformed cells. Low amounts of activated macrophages (MAK) caused regression of experimental tumors in animal models. In cancer patients, MAK were well tolerated and caused tumor necrosis but no clear therapeutic response has been reported up to now. Improvements can be expected using local treatment and more specific macrophages presenting tumor antigens. This restoration of immune recognition of growing tumors with low levels of reactants should ultimately reestablish, after exogenous stimulation, the insufficient immune response of the host against a malignant tumor. Antitumoral macrophages can also be optimized by gene transfection. Macrophages are proposed as stable and long lasting cell vectors for adoptive gene treatments.