Sensitivity of tumour and normal cells to the effect of immune lymphocytes in vitro and some properties of target cells determing this sensitivity.

Cells from various spontaneous mammary tumours of C3H/He mice differ in their sensitivity to immune allogeneic lymphocytes in vitro. Two cell lines, differing in their sensitivity to allogeneic immune lymphocytes in vitro, were obtained from spontaneous mammary tumours which developed in C3H/He mice. Of these two lines, the cell line MT3 was considerably more immunoresistant than line MT5, as demonstrated by microcytotoxic tests in vitro. Furthermore, only the immunoresistant MT3 cell line was capable of growing in syngeneic hosts. During passages in vitro, cells of the line MT5 became as immuno-resistant as cells of the line MT3; concomitantly, cells of the line MT5 started to take in syngeneic hosts. Cell immunosensitivity to immune allogeneic lymphocytes in vitro correlates with that cell property which determines the penetrance rate of intact allogeneic and syngeneic lymphocytes into these cells (emperipolesis). Non-tumourous cells from different C3H/He mouse tissues were more immunoresistant than tumour cells from the two cell lines cultured.