Table 1

Resistance of Meth A tumor cells to lysis by H-2d-specific CTLs1

Target Cells % 51Cr release at E:T ratios:
Exp. 1 Exp. 2
20 10 5 20 10 5
BALB/cJ Con A blasts2 68 65 52 69 55 27
C57BL/6 Con A blasts2 0 0 1 4 0 0
C3H-HeN Con A blasts2 12 10 0 20 14 11
10ME 73 62 49 72 51 29
Meth A ascites 12 8 0 0 0 3
Meth A cultured 25 19 9 17 10 7
CMS4 60 49 37 - - -
CMS5 46 34 23 50 34 20

1C57BL/6 mice were challenged intradermally with 2 x 106 live Meth A cells. After tumor rejection, spleen cells were harvested and cultured with mitomycin C-treated Meth A cells (responder to stimulator ratio 20:1). On day 6 CTLs were tested against the indicated targets in 51Cr release assays. Shown are two representative experiments, of a total of five. 2Con A blasts was prepared by culturing 2 x 107 whole spleen cells in 10 ml complete RPMI with Concanavalin A (final concentration 5 µg/ml). Blasts were harvested after 48 hours and 51Cr-labeled for use as target cells in CTL assays.