CD39-deficient macrophages exhibit impaired regulatory macrophage induction and enhance LPS toxicity in vivo. (A) Levels of TNF-α (black bars), IL-12/23p40 (striped bars), and IL-10 (gray bars) produced by wild-type and Cd39^−/− BMDMs stimulated with LPS for 8 hours. Cytokine production was determined by ELISA. The means ± SEM are shown. (B) Kaplan-Meier survival curves of wild-type mice challenged with 300 μg LPS (intraperitoneal) 3 hours after adoptive transfer (intraperitoneal) of wild-type (closed squares; solid line) or Cd39^−/− BMDMs (open squares; dashed line). Data represent the means of 10 mice per group. (C) The expression of cytokine transcripts from ex vivo peritoneal cells was determined 1 hour post-LPS challenge from wild-type mice receiving 1 × 10⁶ naïve wild-type (solid bars) or Cd39^−/− (striped bars) BMDMs. The means of samples from 4 mice per group ± SEM are shown. WT, wild-type.