Interaction of BCG-activated macrophages with neoplastic and nonneoplastic cell lines in vitro: Cinemicrographic analysis

Abstract

Cultures of adherent peritoneal cells (macrophages) from bacillus Calmette-Guerin (BCG)-infected (BCG macrophages) or from uninfected mice with neoplastic or nonneoplastic target cells were filmed by time-lapse cinemicroscopy. A single film of each of the macrophage-target cell combinations was analyzed in detail. This analysis revealed dramatic changes in both effector and target cell populations. The translational movement of BCG macrophages on tumor cells was up to 5 times the movement observed on nonneoplastic target cells. This effect was not observed with macrophages from uninfected mice. Bacillus Calmette-Guerin macrophage-tumor cell interaction was characterized by repeated and relatively short (2-hr) contacts inducing complete and permanent tumor cytostasis, degenerative morphological changes, and eventual destruction of the tumor monolayer. Bacillus Calmette-Guerin macrophages were partially cytostatic to nonneoplastic target cells, but degenerative changes or target cell death were not observed. Macrophages from uninfected mice had little or no effect on either target cell line.