Correlation between concanavalin A agglutinability and cytotoxic sensitivity to antiserum against tumor-associated antigen in rat fibrosarcoma cells.

An ip transplantation of 3-methylcholanthrene-induced, transplanted fibrosarcoma KMT-17 cells (1 X 10(8)) grew rapidly and killed syngeneic WKA rats in 3-4 days. Agglutinability induced by concanavalin A (Con A) and antigenic expression of KMT-17 cells were investigated in relation to days after ip transplantation. Agglutinability was highest in 1-day-old cells and lowest in 3-day-old cells. The agglutinability of 3-day-old cells increased again when these cells were transplanted into normal rats. The cytotoxic sensitivity of tumor cells to antiserum against tumor-associated surface antigen (TASA) changed simultaneously with the degree of Con A agglutinability. This phenomenon disappeared after artificial infection of tumor cells with Friend murine leukemia virus. The result of the quantitative absorption test at 4 degrees C overnight was that 1- and 3-day-old cells did not differ in their absorbing capacities to anti-TASA sera. However, when the absorption test was done at 37 degrees C for 60 minutes, 1-day-old cells had approximately 16 times more absorbing capacity than 3-day-old cells. However, the cytotoxic sensitivity to antiserum against histocompatibility antigen did not change, regardless of the number of days after ip transplantation. Analysis based on the quantitative absorption test revealed no difference in antibody-absorbing capacities between 1- and 3-day-old cells at both 4 degrees C and 37 degrees C. The relationship between Con A agglutinability and cytotoxic sensitivity to anti-TASA serum is discussed from the viewpoint of "lateral receptor mobility" on the cell surface.