Surface glycopeptide change triggered by contact between normal cells from rat liver and their simian virus 40-transformed cells from the same virus.

Surface glycopeptide changes triggered by mixed culture of normal cells from rat liver cell line WIRL-3 and simian virus 40-transformed cells from the same line were studied. In addition, biologic responses of the normal cells and the transformed cells to three kinds of surface glycopeptides derived from the normal cells, the transformed cells, and these cells in mixed culture were investigated. Surface glycopeptide derived from the mixed culture showed a quantitative increase and a qualitative change in the glycopeptide structure, not detected in the surface glycopeptide of normal cells and transformed cells cultured separately. The surface glycopeptide changes observed in the mixed culture were mainly ascribable to normal cells responding to transformed cells, and a surface glycopeptide change in normal cells induced a qualitative surface glycopeptide change in transformed cells. Differences in biologic response of normal cells and transformed cells to the above three surface glycopeptides were investigated with the use of inhibition of [3H]thymidine uptake of the cells by the three different surface glycopeptide preparations. The inhibition rates of uptake in normal cells were 30% by all three surface glycopeptides (200 microgram/ml culture medium); inhibition rates in transformed cells were 65% by mixed-culture surface glycopeptide, 50% by normal cell-surface glycopeptide, and 35% by transformed cell-surface glycopeptide.