Lymphokine activated killer (LAK) cells in antibody dependent cellular cytotoxicity (ADCC) using MAb 17-1A: a combination of potential usefulness in tumor therapy.

Peripheral blood lymphocytes (PBL) stimulated by interleukin-2 (IL-2) for 48-96h, generated killer cells against the human colon cancer cell line SW948. The killing capacity increased significantly when the specific mouse monoclonal antibody (MAb) 17-1A was present during the lytic process. The chimeric antibody 17-1A determined a significantly stronger cytotoxicity compared to mouse MAb 17-1A. MAb BR55-2 which recognizes a different antigen on SW948 target cells mediated a similar cytotoxicity as MAb 17-1A. Presence of alpha-interferon (IFN) during the lytic assay significantly enhanced the killing of the tumor by lymphokine activated killer (LAK) cells as well as by LAK cells and mouse MAb 17-1A. However, when chimeric MAb 17-1A and LAK cells were used alpha-IFN failed to increase the lytic activity, probably due to already maximum lysis in the system. Combinations of various biological response modifiers such as monoclonal antibodies, IL-2/LAK cells and alpha-IFN carry great promise to improve this kind of therapy for cancer patients.