Fig. 6 | Nature Communications

Fig. 6

From: Small extracellular vesicles containing arginase-1 suppress T-cell responses and promote tumor growth in ovarian carcinoma

Fig. 6The alternative text for this image may have been generated using AI.

Subcutaneously administered EVs transfer ARG1 to local lymph nodes and block OVA-antigen-specific T-cell proliferation. a Right inguinal lymph nodes from C57BL/6 mice were collected 4 or 24 h post EVs (250 µg) or PBS (Neg-ctrl) inoculation, lysed, and analyzed with immunoblotting for V5 tag. Pos-ctrl1: lysate of control lymph node with ex vivo added EVs-ARG1. Pos-ctrl2: lysate from ID8-ARG1-V5 cells. β-actin served as equal protein loading control. b–d OVA-specific, CTV-stained OT-I T-cells were injected i.v. into C57BL/6 mice and 24 h post adoptive transfer 5 μg of OVA protein 100 μg of EVs were injected daily for the consecutive 3 days s.c. into the right thigh. Where indicated, mice received 20 mg/kg of ARG inhibitor (OAT-1746) i.p. twice a day for the 3 following days. Each experimental group consisted of n = 4–9 mice. After 72 h CD8+ T-cells were isolated from right and left (control) inguinal lymph nodes, stained with SIINFEKL-H-2Kb tetramers and analyzed for proliferation. b Percentages (upper graph) and exemplary histograms (lower panel) of proliferating OT-I T cells isolated from mice immunized with ovalbumin (OVA) and injected with control EVs-pLVX or EVs-ARG1 EVs. T-cells isolated from the contralateral lymph node served as negative control (Ctrl LN). Representative experiment out of n = 2 is shown, data show means ± SD, P value was calculated with Kruskal–Wallis with Dunn’s multiple comparison test. c Percentages (upper) and exemplary histograms (lower panel) of proliferating OT-I T cells isolated from mice immunized with OVA and injected with EVs-ARG1 and/or ARG inhibitor OAT-1746. Representative experiment out of n = 2 with similar results is shown, data show means ± SD, P values were calculated with one-way ANOVA with Bonferroni post-hoc test. d Percentages of CD69+ T-cells (left), mean fluorescence intensity (MFI) for CD69 staining (middle) and MFI for CD3ε staining in OT-I T cells isolated from mice immunized with OVA and injected with EVs-ARG1 and/or ARG inhibitor OAT-1746. Representative experiment out of n = 2 is shown. Data show means ± SD, P values were calculated with Kruskal–Wallis with Dunn’s multiple comparison test. Source data for panels b–d are provided as a Source Data file

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