FIG. 1.

Leukemia development in FrCas^E-infected, 667-treated 129/Ev mice depleted of CD8⁺ cells. (A) Design of the experiments conducted with young mice. The timing of infection with FrCas^E and those of 667 and 169.4 MAb administrations are indicated in the figure (d, day; w, week). Four groups of 12 mice each were followed up using the indicated criteria. These groups were as follows: infected/nontreated/nondepleted mice, infected/treated/nondepleted mice, infected/treated/depleted mice, and noninfected/nontreated/depleted mice. “Infected” refers to infection with FrCas^E, “treated” to 667 MAb administration, and “depleted” to 169.4 MAb administration (see text). (B) Splenic CD4⁺ and CD8⁺ cells. Mice treated as described for panel A were sacrificed at various times for flow cytometry assay of the fractions of CD4⁺ and CD8⁺ splenocytes. (C) Survival of mice treated as indicated in panel A. (D) Design of the experiments conducted with adult mice. In addition to the four groups of mice shown in panel A, another group (infected/treated/depleted/challenged) of 12 mice was challenged with FrCas^E on week 8. (E) Splenic CD4⁺ and CD8⁺ cells. Mice treated with the 169.4 MAb as for panel D, or not treated, were sacrificed at various times for flow cytometry assay of the fractions of CD4⁺ and CD8⁺ splenocytes. (F) Survival of mice treated as indicated in panel A. Error bars in panels B and D indicate standard deviations.