Table 1

Tumor immunity often requires CD8+ T cells in the effector phase

Mice, either naïve, immunized, or immunized and treated with anti-CD4 or anti-CD8 mAb, were challenged with the indicated number of tumor cells. Immunization with the same tumor and T-cell subset depletion at the time of challenge was done as described in “Materials and Methods.” Tumor growth was monitored for at least 60 days. Shown are numbers and percentages (in parentheses) of tumor free mice/total number of mice in the group.

MouseChallenged withNaiveImmunized
TumorCell numberControlαCD4 mAbαCD8 mAb
C57BL/6MCA2051 × 1050/10 (0%)4/8 (50%)1/8 (13%)0/7 (0%)
BALB/cJ558L5 × 1060/10 (0%)9/9 (100%)5/5 (100%)0/6 (0%)
BALB/cCT261 × 1051/12 (8%)9/10 (90%)Rejection*No rejection*
DBA/1NIHpEJcl31 × 1051/10 (10%)9/10 (90%)Rejection*No rejection*
  • * For CT26 or NIHpEJcl3 tumor models, it has been shown that CD8+ but not CD4+ T-cell depletion at the time of challenge abrogated tumor rejection (23 , 24) .