(A) Experimental scheme. Eight-day-old pups were infected and treated with the 667 mAb as indicated. Mice were treated as indicated with the anti-Ly6G 1A8 mAb or the isotype control 2A3 mAb in neutrophil depletion experiments. (B and C) Neutrophil recruitment and infected cell rate in spleen. Splenocytes from naive, infected/nontreated (I/NT), and infected/treated (I/T) mice were analyzed by flow cytometry on day 8 p.i. for (a) neutrophil recruitment (percentage of Ly6G+ cells) and (b) retroviral positivity of splenocytes (percentage of Gag+ cells) gated in the CD45.2+ population. The data presented correspond to 5 independent experiments, with at least 15 mice per group. (D) Mouse survival. Naive, I/NT, and I/T mice were treated with either the antineutrophil (1A8) or the control (2A3) mAb as indicated in A and followed up for leukemic death. The data represent 2 independent experiments, with 6–9 mice per group. (E) Infected cells rate upon neutrophil depletion. Neutrophils of naive, I/NT, and I/T mice were depleted, or not, as indicated in A and infected splenocytes were assayed as in C on day 8 p.i. The data represent 4 independent experiments, with 9–15 mice per group. Data are expressed as mean ± SEM. Statistical significance was established using a parametric 1-way ANOVA test with a Bonferroni correction (*P < 0.05; **P < 0.01; ***P < 0.001).