Table III.
Suppression by CD4+ cells is in effector phase rather than priming phase
| Tumor challengea | |||||
|---|---|---|---|---|---|
| Group | Tumor line | Dose | Anti-CD4 treatment day relative to tumor challenge [0]b |
Incidence of tumor growthc | Percent |
| 1 | Ag104Ld | 105 | −3 and 10 | 0/13 | 0 |
| 2 | −3 | 11/12 | 92 | ||
| 3 | 20 | 0/21 | 0 | ||
| 4 | 5 × 105 | 20d | 0/8 | 0 | |
a
Number of tumor cells as indicated were injected s.c. to C3B6F1 mice.
b
Assume that tumor challenge is on day 0. CD4+ cells were depleted by anti-CD4 antibody. Days on which CD4+ cells were absent were confirmed by checking peripheral blood by FACS.
c
The results were pooled from multiple independent experiments. p-values calculated by chi-square test between groups were shown as follows: P < 0.001 for group 1 versus group 2 and group 2 versus group 3.
d
The average tumor size reached >500 mm3.