Extended Data Figure 1. Adoptively transferred splenocyte cells from adult mice are retained but do not become activated in L. monocytogenes (Lm)-infected neonatal mice.

a, The proportion of adult CD45.1⁺ donor cells compared with endogenous neonatal CD45.2⁺ cells among unfractionated splenocytes or various cell subsets 48 h after transfer to 5-day-old neonatal mice. b, The proportion of TNF-α-producing CD11c⁺ or B220⁺ cells among endogenous cells in adult or neonatal mice, or among transferred adult cells within neonates. c, Restored TNF-α production among neonatal cells after transfer to adult mice. The proportion of TNF-α-producing CD11b⁺ cells among transferred neonatal cells compared with endogenous adult cells. Forty-eight hours after infection, splenocytes were collected from infected or control mice, cultured in medium containing brefeldin A for 5 h and then subjected to cell surface and intracellular cytokine staining. Each point represents data from an individual mouse, and the data are representative of three independent experiments. Error bars, mean±s.e.m.