Fig. 1.

Acceleration of tumor growth in BALB-neuT mice by depletion of both CD4⁺ T cells and CD8⁺ T cells. a BALB-neuT mice were treated with anti-CD4 antibody (GK1.5) and anti-CD8 (2.43) antibody (0.5 mg/injection at day 0, 1, 2, 5, 9) starting from the age of 8 weeks, then weekly until 25 weeks (anti-CD4 and anti-CD8 group vs rat IgG group, P < 0.001 by log-rank test on the entire curves). b BALB-neuT mice were treated with anti-CD4 antibody (GK1.5) or anti-CD8 (2.43) antibody. Control mice were treated with rat Ig. No significant difference was found between groups in b. Five mice were used for each group. Left panels mean number of tumors per mouse; right panels cumulative tumor incidence for the entire group (independent tumors in 50 mammary glands). Similar results were obtained in repeated experiments and a representative is shown. c PBMC from two mice (upper and lower panels, right) depleted by 5 injections of anti-CD4 and anti-CD8 as described above were obtained one day after the fifth dose of antibody and stained for with FITC-anti-CD4 and PE-anti-CD8 as described in “Materials and methods” section, or with isotype control antibodies (not shown). For comparison, at left are shown similar staining plots of PBMC obtained from mice treated in vivo with control rat IgG. Depleting antibodies were found not to compete with staining antibodies