T-cell transformation assay with herpesvirus saimiri C488 wild type (C488 wt and M11 wt), ΔCSKH, mSH3B, and ΔCSKH mSH3B. Stimulated human CBL were infected and cultured in the presence of exogenous IL-2. Proliferation was monitored by automated cell counting, and total cell numbers were calculated as outlined in Materials and Methods. The median values and standard deviation (error bars) of each time point were determined from three independent donors. C488 wt, wild-type isolate; M11 wt, wild type reconstituted from cosmids.