TLR4 signaling in MDSCs. (A) MDSC-IL13s treated as indicated for inflammasome induction with LPS (0.2 μg/mL) for 3 hours followed by ATP (2 mM) for 1 hour were harvested and aliquoted for FLICA analysis, shown as mean fluorescence intensity (MFI), gated on CD11b⁺Ly6C⁺ fraction; 2 replicates per condition. (B) Supernatants from cultures were assayed for IL-1β production by ELISA; 2 replicates per condition. (C) Harvested MDSC-IL13s were washed, counted, and plated in a CFSE suppression assay at a 1:1 ratio with naïve B6-purified CD25-depleted whole T cells stimulated with anti-CD3ε. Data represent fraction of CD8⁺ T cells having undergone ≥1 division; 3 replicates per condition. (D) Kaplan-Meier survival curve for lethally irradiated Balb/c recipients given 1e7 B6 BM cells plus 2e6 purified CD25-depleted whole T cells (WTCs) and 6e6 MDSC-IL13s (M13) or MyD88 KO MDSC-IL13s, as indicated. WTCs vs M13, P = .0001; WTCs vs MyD88 KO, P = .0460; M13 vs MyD88 KO, P = .5988. Data represent 3 independent pooled experiments with n = 30 animals per group. (E) Kaplan-Meier survival curve, as in panel D, giving 6e6 WT MDSC-IL13s (M13) or 6e6 MyD88/TRIF dKO MDSC-IL13s. WTCs vs M13, P = .0012; WTCs vs MyD/TRIF dKO, P < .0001; M13 vs MyD88/TRIF dKO, P = .0561. Data represent 2 independent pooled experiments with n = 20 per group. *P < .05, **P < .01, ***P < .001. txt, treatment.