FIG. 3.

Minimal estimate of the frequency of B6 pCTL/CTL specific for syngeneic GCSA⁺ E♂G2 tumor cells. Solid arrows illustrate the kinetics of the treatment conditions of B6 spleen cells, which included in vivo priming (of B6 mice) with 10⁶ B.GV tumor cells, in vitro restimulation of polyclonal spleen cells with E♂G2 tumor cells without or with AKR.H-2^b spleen cells, and establishment of limiting-dilution cultures of immune spleen cells (taken directly from the immunized mouse or from MLTC wells obtained at the end point). Dashed arrows identify the results of ⁵¹Cr release assays, which include the pCTL/CTL frequency following in vivo priming of B6 mice, bulk CTL data following polyclonal restimulation (inset), and the pCTL/CTL frequency of primed and restimulated (restim.) B6 spleen cells. The estimates of probability as determined by χ² minimization, where significance is indicated by P > 0.05, are shown in parentheses.