Skip to main content
Fig. 7 | Journal for ImmunoTherapy of Cancer

Fig. 7

From: Tumor-released autophagosomes induces CD4+ T cell-mediated immunosuppression via a TLR2–IL-6 cascade

Fig. 7

Knockdown of Beclin1 or knockout of IL-6 inhibits tumor growth and alters CD4+T and B cells polarization. a ELISA of IL-6, IL-10, and IL-21 secretion by CD4+ T cells treated with CM, or media from negative control (NC) or Becn1-knockdown (KD) B16F10 cells in the presence of anti-CD3/CD28 for 72 h. b-f Control (NC) or Becn1-KD B16F10 cells were inoculated s.c. into C57BL/6 mice (n = 6 per group). Twenty-one days later, serum IL-6 level was measured by ELISA (b). The frequency of IL-10+ CD4+ T cells (c), IL-21+ CD4+ T cells (d), IFN-γ+ CD4+ T cells (e), and IL-10+ B cells (f) in tumor-draining lymph nodes (dLN) or tumor tissues (Tumor) were analyzed by flow cytometry. g-j The tumor-bearing mice (n = 5 per group) were depleted of either CD4+ or CD8+ T cells or CD20+ B cells by intravenous administration of 250 μg/mouse of anti-mouse CD4 or anti-mouse CD8 antibodies twice weekly throughout the course of tumor growth, or 250 μg of anti-mouse CD20 antibodies, respectively. Control mice were treated with isotype-matched control antibodies. g Tumor growth was monitored by calipers. h, i The frequency of CD4+ IFN-γ+ and CD8+ IFN-γ+ T cells in tumor infiltrating lymphocytes were determined by intracellular staining. j The frequency of B cells in tumor infiltrating lymphocytes were determined by flow cytometry. k-n WT or Il6−/− C57BL/6 mice were inoculated s.c. with B16F10 cells. On day 21, the frequencies of IL-10+ CD4+ T cells (k), IL-21+ CD4+ T cells (l), and IL-10+ B cells (m) in dLN and tumor tissues were evaluated by flow cytometry. n Tumor size was measured by caliper. o, p B16F10 tumor cells were mixed with WT TTRAP or Il6−/− TTRAP and injected s.c. into C57BL/6 mice (n = 6 per group). The growth of the tumor was monitored. o, q B16F10 tumor cells were i.v. injected into C57BL/6 mice (n = 6 per group). Subsequently, WT TTRAP or Il6−/− TTRAP were transferred i.v. every other day for 3 times. Three weeks later, tumor nodules in the lungs were examined. r A proposed model for the mechanisms and immunosuppressive functions of TRAPs-induced CD4+ T cells. Data (mean ± SEM) represent 3 independent experiments. *, P < 0.05; **, P < 0.01; ***, P < 0.001; ns, not significant, by 1-way ANOVA with the Tukey-Kramer multiple test, 2-tailed unpaired t-test or Mann-Whitney U test

Back to article page