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Efficacy of vaccination with tumor-exosome loaded dendritic cells combined with cytotoxic drug treatment in pancreatic cancer.

ABSTRACT: Pancreatic cancer (PaCa) has a dismal prognosis and adjuvant immunotherapy frequently is of low efficacy due to immunosuppressive features of PaCa and PaCa-stroma. We here explored, whether the efficacy of vaccination with tumor-exosome (TEX)-loaded dendritic cells (DC) can be improved by combining with drugs affecting myeloid-derived suppressor cells (MDSC). Experiments were performed with the UNKC6141 PaCa line. UNKC6141 TEX-loaded DC were weekly intravenously injected, mice additionally receiving Gemcitabine (GEM) and/or ATRA and/or Sunitinib (Sun). UNKC6141 grow aggressively after subcutaneous and orthotopic application and are consistently recovered in peripheral blood, bone marrow, lung and frequently liver. Vaccination with DC-TEX significantly prolonged the survival time, the efficacy of DC-TEX exceeding that of the cytotoxic drugs. However, ATRA, Sun and most efficiently GEM, sufficed for a pronounced reduction of MDSC including tumor-infiltrating MDSC, which was accompanied by a decrease in migrating and metastasizing tumor cells. When combined with DC-TEX vaccination, a higher number of activated T cells was recovered in the tumor and the survival time was prolonged compared with only DC-TEX vaccinated mice. As ATRA, GEM and Sun affect MDSC at distinct maturation and activation stages, a stronger support for DC-TEX vaccination was expected by the drug combination. Intrapancreatic tumor growth was prevented beyond the death of control mice. However, tumors developed after a partial breakdown of the immune system by the persisting drug application. Nonetheless, in combination with optimized drug tuning to prevent MDSC maturation and activation, vaccination with TEX-loaded DC appears a most promising option in PaCa therapy.

SUBMITTER: Xiao L

PROVIDER: S-EPMC5486185 | biostudies-literature | 2017

REPOSITORIES: biostudies-literature

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Efficacy of vaccination with tumor-exosome loaded dendritic cells combined with cytotoxic drug treatment in pancreatic cancer.

Xiao Li L Erb Ulrike U Zhao Kun K Hackert Thilo T Zöller Margot M

Oncoimmunology 20170420 6

Pancreatic cancer (PaCa) has a dismal prognosis and adjuvant immunotherapy frequently is of low efficacy due to immunosuppressive features of PaCa and PaCa-stroma. We here explored, whether the efficacy of vaccination with tumor-exosome (TEX)-loaded dendritic cells (DC) can be improved by combining with drugs affecting myeloid-derived suppressor cells (MDSC). Experiments were performed with the UNKC6141 PaCa line. UNKC6141 TEX-loaded DC were weekly intravenously injected, mice additionally recei ...[more]

PMID: 28680753

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Project description:BackgroundSunitinib, a tyrosine kinase inhibitor currently in use for the treatment of metastatic renal cell carcinoma (mRCC), has been reported to modulate immunosuppressive cells such as myeloid-derived suppressor cells (MDSCs) and regulatory T cells (Tregs) in addition to exerting anti-angiogenic effects. We conducted a clinical trial of dendritic cell (DC)-based immunotherapy together with sunitinib in mRCC patients in an effort to enhance immunotherapeutic efficacy by inhibiting immunosuppressive cells.MethodsPatients aged ≥20 years with advanced or recurrent mRCC who underwent nephrectomy were eligible for this study. Autologous tumor samples were obtained by surgery under aseptic conditions and used for preparing autologous tumor lysate. About 4 weeks after surgery, leukapheresis was performed to isolate peripheral blood mononuclear cells (PBMCs). DCs were generated from adherent PBMCs in the presence of recombinant human granulocyte macrophage colony-stimulating factor (GM-CSF) (500 IU/ml) and recombinant human IL-4 (500 IU/ml). Autologous tumor lysate was loaded into mature DC by electroporation. Eight patients were enrolled in the study and received sunitinib at a dose of 50 mg p.o. daily for 28 days followed by 14 days of rest. Tumor lysate-loaded DCs were administered subcutaneously every two weeks, with concomitant sunitinib.ResultsNo severe adverse events related to vaccination were observed. Sunitinib decreased the frequencies of MDSCs in peripheral blood of 5 patients and of Tregs in 3. Tumor lysate-reactive CD4 or CD8 T cell responses were observed in 5 patients, 4 of whom showed decreased frequencies of Tregs and/or MDSCs. The remaining 3 patients who failed to develop tumor-reactive T cell responses had high levels of IL-8 in their sera and did not show consistent reductions in MDSCs and Tregs.ConclusionsDC-based immunotherapy combined with sunitinib is safe and feasible for patients with mRCC.Trial registrationUMIN000002136.

Project description:Most pancreatic adenocarcinoma patients present with unresectable disease and benefit little from chemotherapy. Poor tumor perfusion and vascular permeability limit drug deposition. Previous work showed that Smoothened inhibitors of hedgehog signaling (sHHI) promote neovascularization in spontaneous mouse models of pancreatic cancer (PaCA) and enhance tumor permeability to low-molecular weight compounds. Here, we tested the hypothesis that sHHI can enhance tumor deposition and efficacy of drug-containing nanoparticles consisting of 80 to 100 nm sterically-stabilized liposomes (SSL) containing doxorubicin (SSL-DXR). SCID mice bearing low-passage patient-derived PaCA xenografts (PDX) were pretreated p.o. for 10 days with 40 mg/kg/d NVP-LDE225 (erismodegib), followed by i.v. SSL-DXR. Microvessel density, permeability, perfusion, and morphology were compared with untreated controls, as was SSL deposition and therapeutic efficacy. The sHHI alone affected tumor growth minimally, but markedly increased extravasation of nanoparticles into adenocarcinoma cell-enriched regions of the tumor. Immunostaining showed that sHHI treatment decreased pericyte coverage (α-SMA(+)) of CD31(+) vascular endothelium structures, and increased the abundance of endothelium-poor (CD31(-)) basement membrane structures (collagen IV(+)), suggesting increased immature microvessels. SSL-DXR (15 mg/kg) administered after sHHI pretreatment arrested tumor volume progression and decreased tumor perfusion/permeability, suggesting an initial vascular pruning response. Compared with controls, one cycle of 10-day sHHI pretreatment followed by 6 mg/kg SSL-DXR doubled median tumor progression time. Three cycles of treatment with sHHI and SSL-DXR, with a 10-day between-cycle drug holiday, nearly tripled median tumor progression time. Based upon these data, short-term sHHI treatment sequenced with nanoparticulate drug carriers constitutes a potential strategy to enhance efficacy of pancreatic cancer therapy.

Dataset Information

Efficacy of vaccination with tumor-exosome loaded dendritic cells combined with cytotoxic drug treatment in pancreatic cancer.

Publications

Efficacy of vaccination with tumor-exosome loaded dendritic cells combined with cytotoxic drug treatment in pancreatic cancer.

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