Local reconstitution of CD8⁺ DCs inhibits systemic concomitant immunity. Mice were inoculated with B16 cells (10⁵) in the left ear on day 0, and reinoculated with B16 (2.5 × 10⁵) in the right shoulder on day 6. Mice were either untreated (no CTX) of treated with CTX (CTX) 4 days before the primary tumor challenge (A). Mice were treated with CTX as described for panel A and received 10⁶ CD8⁺ DCs in the left ear 1 day before the primary tumor challenge or were treated with CTX and received 10⁶ CD8⁻ DCs in the left ear using the same timeline (B). The left graphs represent growth of primary tumors, the right graphs depict growth of challenge secondary tumors. P values for the primary tumor were not statistically significant except no CTX and CTX + CD8⁻ DCs (P = .002). P values comparing growth curves between no CTX with CTX, CTX + CD8⁺ DCs, and CTX + CD8⁻ CCs were < .001, .031, and < .001, respectively. The P value comparing CTX versus CTX + CD8⁺ DCs was .004. The growth of the second challenge tumor inoculum in naive mice without primary tumor challenge (with or without CTX treatment; C). Data from 1 of 2 independent experiments with similar results are shown.