Sensitivity to guinea‐pig serum of hamster cells transformed in vitro by two strains of the rous sarcoma virus

Abstract

BHK 21/13 hamster cells transformed in vitro by the Bryan (RB 12) and the Schmidt-Ruppin (RS2) strains of Rous sarcoma virus differ in their behaviour in tissue culture (Montagnier et Vigier, 1967). Whereas RS 2 cells have retained the spindle shape of the parental BHK 21/13 cells and show some contact inhibition of division in monolayers, RB 12 cells, on the contrary, are large rounded cells which rapidly pile up. RB 12 cells also have a higher cloning eficiency than R S 2 cells in liquid medium or soft agarose, and they are less dependent on environmental factors, such as composition of media and presence of feeder cells.The two kinds of cells differ also in some surface properties, and RS 2 cells were recently found to be more sensitive than RB 12 cells to the cytotoxic action of antisera directed against the RSV-induced surface antigen (VISA) (Bataillon, 19736).Comparative sensitivity of untransformed BHK 21/13, RB 12 and RS 2 cells to normal guinea-pig (GP) serum is presented in this paper.Whereas BHK 21-13 cells were highly sensitive to the cytotoxic action of GP serum, cells transformed by RSV had a reduced sensitivity (RS 2) or were entirely insensitive (RB 12). Mild treatment of the cells with Vibrio cholerae neuraminidase, which did not affect the sensitivity of BHK 21/13 and RS 2cells, rendered the RB 12 cells significantly sensitive to the cytotoxic action of normal GP serum. MATERIAL AND METHODS C e hRB 12/1, RB 1214, RS 213, RS 2/10 and RS 216 are five subclones derived from BHK21/13 hamster cells (Macpherson and Stoker, 1962) transformed in vitro with B-RSV [RAV-I] (clone RB 12) and SR-RSV (clone RS 2) respectively (Montagnier et Vigier, 1967;Vigier, 1967). C 13/15 and C 13/8, two subclones of BHK 21/13 isolated by Dr. L. Montagnier, and some properties of C 1318 cells, which are asparagine-dependent, have already been described .