Lymphocyte interactions with the extracellular matrix of malignant cells in vitro: a morphological and...

The interactions of lymphocytes with the glycosaminoglycans-protease-membrane extracellular matrix, produced by mixed cell cultures of normal with malignant cell clones, were examined. Pre-activated and activated heterologous peripheral lymphocytes were used. Co-cultures of activated lymphocytes with all cell types used, formed identical cell nodules. Histology of cell nodules showed that activated lymphocytes were cytolytic to pure normal or malignant cell clones. On the contrary, lymphocytes in nodules with mixed cell clones (normal with malignant cell clones) or embryonic cells, underwent degeneration changing the fusiform type tumor nodule into the adenoid type. The adenoid type cell nodule consisted of cells with high nuclear to cytoplasm ratio and mitotic activity. In addition, leukocyte common antigen was deposited in the extracellular matrix and on the cell membrane of target tumor cells. Pre-activated lymphocytes, in mixed cell cultures, failed to lyse the target tumor cells and underwent abnormal cell divisions, producing subsets similar to nuclear vlimata, which remained attached to the extracellular matrix. The morphological and immunocytochemical observations of lymphocytes were discussed and attributed to the presence of the specific extracellular matrix of glycosaminoglycans-protease-membranes.