Figure 2.

Ability to control GVHD with GCV after infusion of 2 × 10⁶, 4 × 10⁶, or 8 × 10⁶ TK⁺TC. (A): Mice were given transplants as described in Materials and methods of 1 × 10⁷ bone marrow cells (BM, ●) alone (to serve as a GVHD control in this model as the marrow has insufficient lymphocytes to initiate GVHD) or bone marrow cells plus 2 × 10⁶ unmanipulated T cells (NL, ■) or TK⁺TC (TK, ▲) or TK⁺TC followed by intraperitoneal (IP) administration of GCV on days 10 through 16 (TK⁺GCV, Δ). Results from several experiments are combined for the three control groups and from two experiments for the TK⁺GCV group. The number of mice treated is shown in parentheses by each curve. The survival time of mice receiving either bone marrow only or TK⁺TC plus GCV was significantly longer compared with mice receiving either unmanipulated T cells or TK⁺TC without GCV (p < 0.00001 for all four comparisons). (B): Mice were transplanted as described in the Material and methods with 1 × 10⁷ bone marrow cells alone (BM, ●) or along with 4 × 10⁶ unmanipulated T cells (NL, ■), or TK⁺TC (TK, ▲) or TK⁺TC with administration of GCV via an Alzet pump on days 10 through 16 (TK⁺GCV, Δ). Results from several experiments are combined for the three control groups and from two experiments for the group receiving GCV. The number of mice treated is shown in parentheses by each curve. The survival of mice receiving bone marrow only or TK⁺TC plus GCV was significantly longer than that of mice receiving either unmanipulated T cells or TK⁺TC without GCV (p < 0.00002 for all four comparisons). (C): Mice were transplanted as described in Material and methods with 1 × 10⁷ bone marrow cells alone (BM, ●) or along with 8 × 10⁶ or TK⁺TC (TK, ▲) or TK⁺TC with administration of GCV via Alzet pump on days 7 through 13 (TK⁺GCV Days 7–13, □) or on days 10 through 16 (TK⁺GCV Days 10–16, Δ). Results from several experiments are combined for the three control groups and from one experiment for the groups that received GCV. The number of mice treated is shown in parentheses by each curve. The survival time of mice receiving TK⁺TC + GCV on days 10 through 16 was significantly longer than that of mice receiving TK⁺TC without GCV (p < 0.0001) and was statistically similar to that of bone marrow only controls (p = 0.25). The survival time of mice receiving TK⁺TC plus GCV on days 7 through 13 was statistically similar to that of mice receiving TK⁺TC without GCV (p = 0.63) or those receiving TK⁺TC + GCV on days 10 through 16 (p = 0.17) but was inferior to that of the bone marrow–only controls (p = 0.05).