Fig. 5

HSP70 may play a key role in the shikonin-induced ICD for enhancing anti-metastasis activity of DC-based cancer vaccines. Specific ICD protein components (i.e., HSP70, CRT or HMGB1) were depleted from SK-TCL samples before they were used as an adjuvant for preparation of a DC-based cancer vaccine. Test mice (8 mice/group) were injected with different vaccine formulations [i.e., iDCs, mDCs + Naive-TCL, mDCs + SK-TCL, mDCs + SK-TCL(−HSP70), mDCs + SK-TCL(−CRT), mDCs + SK-TCL(−HMGB1)] three times (see Materials and Methods), and mice were monitored for metastasis status and survival rate was scored for three months. a Representative in vivo bioluminescent images of test mice treated with different vaccine regimes after the resection of the 4 T1 orthotopic primary tumors. The red signals represent the highest level on the colorimetric scale. b Percentage of whole body organ free from metastasis in mice. The metastasis levels of tumors in test mice were scored by bioluminescence imaging within the indicated time period. c Survival rate of test mice treated with the indicated DC vaccine formulations, after tumor resection. A P value of less than 0.05 was considered significant (*, P < 0.05). d Ten days after the last vaccination, the percentages of monocytic MDSCs (CD11b⁺Ly6C⁺) and granulocytic MDSCs (CD11b⁺Ly6G⁺) in the blood of test mice were analyzed using flow cytometry. Similar trends of results were obtained from three independent experiments shown in (a), (b) and (c), and from two independent experiments shown in (d)