a, Schematic of adoptive transfer: 3-month-old progeroid Ercc1−/∆ mice (n = 4 mice/treatment group) were injected retro-orbitally with 5x106 splenocytes from 2-month-old WT mice or vehicle only (PBS) (n = 6 donors). One month later, the recipient mice and uninjected age-matched wild-type mice were euthanized, and tissues collected. b, Expression of senescence markers in organs of recipient mice (n = 4 Ercc1−/∆ + splenocytes; n = 3–6 Ercc1−/∆ + PBS) (see Supplementary Table 3 for sample size details by organ/endpoint). Gene expression was normalized to that of uninjected, age-matched wild-type controls (n = 4–7) represented as horizontal dashed line. c, SASP factor proteins MCP-1 and TNF were measured in the serum of recipient mice by multiplex ELISA (n = 4 Ercc1−/∆ + splenocytes; n = 6 Ercc1−/∆ + PBS) and compared to untreated, age-matched wild-type mice (n = 4–6). d, Footpad swelling of mice describe above and in Fig. 5f at several time points after antigenic challenge (n = 3/7 Vav-iCre+/−;Ercc1−/fl or n = 3/6 Vav-iCre+/− mice +/− rapamycin, respectively). e, Expression of p21 in PBMCs, measured by qRT–PCR. f, Serum MCP-1 and TNF measured by multiplex ELISA (n = 3/5 +/− rapamycin, respectively). Data are mean ± s.d. *P < 0.05, ∞P < 0.01, ∇P < 0.001, #P < 0.0001 one-way ANOVA (b, c) or two-way ANOVA (d–f) with Tukey’s test. Mouse images in schematic were used with permission from BioRender.