In vitro studies on tumor-specific immunity by using C3H mammary cancer-A cells. 3. Specificity of aggregation of sensitized lymph-node cells on target cells

As a link in the series of studies on tumor specific immunity an attempt was made to clarify specificity if any, in aggregation of sensitized lymph-node cells on target cell in vitro. For this purpose sensitized regional lymph-node cells from isologous CsH mouse transplanted with A cells derived from CaH mouse mammary cancer were incubated with M cells derived from mammary cancer of homologous Cb mouse and HeLa-Ss cells as with A cells. The results are briefly summarized in the following. These sensitized regional lymph-node cells (A-L) inhibited the proliferation of A cells and M cells in tissue culture. When the interaction between the sensitized lymph-node cells and the terget cells was pursued over a long period by cinematography, these lymph-node cells became attached to the target cell by 6-to 12-hour culture in aggregation of rosette form, and by 30 hours some of the target cells were seen to undergo lysis. However, when these sensitized lymph-node cells were cultured with heterologous HeLa-S3 cells (derived from human uterine cancer), no such phenomena were observed. In the case with untreated normal lymph-node cells (control) there could be hardly observed any inhibitory effect on target cells. When the number of the target cells on which the lymph-node cells became attached was counted along with lapse of time, it was more numerous in the case of A and M cells but only a few in the case of HeLa-S3 cells. It seems that most of the sensitized lymph-node cells that inhibit the growth of the target cells become attached and aggregated fairly specifically onto the target cells.