Tumor exosomes inhibit BMDC maturation and induce TGF-β1 production.

<p>(A) Day 8 BMDCs (purity >90%) were treated with 10 µg/ml of tumor exosomes or cultured untreated for 3 days. The expression of I-A^b and CD86 were analyzed by FACS. LPS treatment (1 µg/ml) for 24 h was used as a DC maturation control. (B) TGF-β1 protein levels (pg/ml) in DC culture supernatants after exosome treatment. Data show the mean values of two independent experiments ± SD. (C) TGF-β1 contents in exosome preparations (pg/10 µg of exosomes). For each exosome sample, the data shown represent the mean value of three preparations ± SD.</p

qRT-PCR analysis of cytokines and FoxP3 mRNA levels in the draining popliteal LN associated with DTH suppression.

<p>Panels show the relative mRNA levels of TGF-β1 (A), IL-4 (B), IL-10 (C), IFN-γ (D) and FoxP3 (E) normalized to β-actin mRNA level in the treated-side popliteal LNs 48 h after EL4 exosomes, EG7 exosomes or PBS treatment at the time of OVA challenge. n = 5. **: P<0.01; *: P<0.05; NS: not significant.</p

Characterization of tumor exosomes.

<p>(A) EM micrographs of exosomes isolated from EL4, EG7, B16 and MO5 cell culture supernatants. (B) Western blot analysis of exosomes and cell lysates. 10 µg of proteins were loaded per lane. (C) IP detection of OVA protein (40∼45 kD) in both cell lysates and exosomes. (D) FACS analysis of MHC class I, MHC class II and CD81 expression on cells and exosomes.</p

Suppression of OVA-specific DTH response by local administration of MO5 exosomes.

<p>Mice pre-sensitized with OVA were injected with 10 µg of B16 exosomes, 10 µg of MO5 exosomes or PBS alone in their right hind paws and were challenged with OVA at both hind paws. Paw swellings were measured 24 h and 48 h post-challenge. (A) Representative results showing the increase in footpad thickness (×0.01 mm) of treated and contralateral paws. n = 5. (B) Pooled results of two independent experiments showing the fold increase in footpad thickness as compared to the treated paws in PBS group. n = 10. **: P<0.01; *: P<0.05; NS: not significant.</p