Antitumor factors of draining lymph node cells of the mouse sensitized with ehrlich ascites tumor cells. I. Antitumor effect of subcellular factor

The regional lymph node cells of the mice sensitized with Ehrlich ascites tumor cells is known to possess a substance that shows antitumor activity on target cells (JTC-II cells). For the purpose to clarify the localization of this substance the regional lymph node cells from such sensitized mice were treated with trypsin solution of different concentrations (1.0 %, 0.2 %, and 0.01 %), and the tissue culture was carried out with JTC.II cells. As a result it was found that these lymph node cells lost antitumor activity. Next, by the differential contrifugation of these sensitized lymphocytes we obtained F1 fraction (700 g, sediment), F2 (8,500 g sediment), F3 (100,000 g sediment) and F4 (100,000 g supernatant). In the presence of each of these fractions tissue culture was conducted with JTC-II cells as target cells, and it was found that the substance with antitumor activity is contained abundantly in F2 fraction (8,500 g sediment) and F4 fraction (100,000 g supernatant). After giving due consideration to the results of these two experiments and also to the available data in the literature, we assume that the substance with antitumor activity is contained in the cell membrane component.