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.