Fig. 3.

Transformation assays performed with nW viruses. (A) Histograms representing the numbers of 96 replicate wells, each seeded at 10⁴ cells/well, that transformed after infection of cells with the 0W to 6W viruses at the indicated MOI; the data represent the results from one representative assay scored at 6 weeks p.i. (B) Calculation of the transformation efficiency of the 0W to 6W viruses. The MOI required for transformation of 50% of the wells (Moi 50% tr) was determined by plotting the number of transformed wells as shown in panel A against the log₁₀ MOI. (C) The effect of a mitogenic signal on transformation. Transformation assays were carried out as described for panel A with the 2W and 5W viruses with or without the addition of soluble CD40 ligand (50 ng/ml) and IL-4 (50 ng/ml). The numbers of wells showing transformation at 6 weeks p.i. were plotted against the log₁₀ MOI to determine the MOI required for transformation of 50% of the wells.