Table III.

Suppression by CD4+ cells is in effector phase rather than priming phase

Tumor challengea
GroupTumor lineDoseAnti-CD4 treatment
 day relative to tumor challenge [0]bIncidence of tumor growthcPercent
1Ag104Ld105−3 and 100/130
45 × 10520d0/80
  • 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.