| Autor: |
Vogt A; Department of Internal Medicine I, University Hospital of Bonn, 53127 Bonn, Germany., Sadeghlar F; Department of Internal Medicine I, University Hospital of Bonn, 53127 Bonn, Germany., Ayub TH; Department of Internal Medicine I, University Hospital of Bonn, 53127 Bonn, Germany., Schneider C; Department of Internal Medicine I, University Hospital of Bonn, 53127 Bonn, Germany., Möhring C; Department of Internal Medicine I, University Hospital of Bonn, 53127 Bonn, Germany., Zhou T; Department of Internal Medicine I, University Hospital of Bonn, 53127 Bonn, Germany., Mahn R; Department of Internal Medicine I, University Hospital of Bonn, 53127 Bonn, Germany., Bartels A; Department of Internal Medicine I, University Hospital of Bonn, 53127 Bonn, Germany., Praktiknjo M; Department of Internal Medicine I, University Hospital of Bonn, 53127 Bonn, Germany., Kornek MT; Department of Internal Medicine I, University Hospital of Bonn, 53127 Bonn, Germany., Toma M; Department of Pathology, University Hospital of Bonn, 53127 Bonn, Germany., Schmidt-Wolf IGH; Department of Integrated Oncology (CIO), University of Bonn, 53127 Bonn, Germany., Branchi V; Department of Visceral Surgery, University Hospital of Bonn, 53127 Bonn, Germany., Matthaei H; Department of Visceral Surgery, University Hospital of Bonn, 53127 Bonn, Germany., Kalff JC; Department of Visceral Surgery, University Hospital of Bonn, 53127 Bonn, Germany., Strassburg CP; Department of Internal Medicine I, University Hospital of Bonn, 53127 Bonn, Germany., Gonzalez-Carmona MA; Department of Internal Medicine I, University Hospital of Bonn, 53127 Bonn, Germany. |
| Abstrakt: |
Dendritic cells (DC) as professional antigen presenting cells are able to prime T-cells against the tumor-associated antigen α-fetoprotein (AFP) for immunotherapy of hepatocellular carcinoma (HCC). However, a strong immunosuppressive tumor environment limits their efficacy in patients. The co-stimulation with CD40Ligand (CD40L) is critical in the maturation of DC and T-cell priming. In this study, the impact of intratumoral (i.t.) CD40L-expressing DC to improve vaccination with murine (m)AFP-transduced DC (Ad-mAFP-DC) was analyzed in subcutaneous (s.c.) and orthotopic murine HCC. Murine DC were adenovirally transduced with Ad-mAFP or Ad-CD40L. Hepa129-mAFP-cells were injected into the right flank or the liver of C3H-mice to induce subcutaneous (s.c.) and orthotopic HCC. For treatments, 10 6 Ad-mAFP-transduced DC were inoculated s.c. followed by 10 6 CD40L-expressing DC injected intratumorally (i.t.). S.c. inoculation with Ad-mAFP-transduced DC, as vaccine, induced a delay of tumor-growth of AFP-positive HCC compared to controls. When s.c.-inoculation of Ad-mAFP-DC was combined with i.t.-application of Ad-CD40L-DC synergistic antitumoral effects were observed and complete remissions and long-term survival in 62% of tumor-bearing animals were achieved. Analysis of the tumor environment at different time points revealed that s.c.-vaccination with Ad-mAFP-DC seems to stimulate tumor-specific effector cells, allowing an earlier recruitment of effector T-cells and a Th1 shift within the tumors. After i.t. co-stimulation with Ad-CD40L-DC, production of Th1-cytokines was strongly increased and accompanied by a robust tumor infiltration of mature DC, activated CD4 + -, CD8 + -T-cells as well as reduction of regulatory T-cells. Moreover, Ad-CD40L-DC induced tumor cell apoptosis. Intratumoral co-stimulation with CD40L-expressing DC significantly improves vaccination with Ad-mAFP-DC in pre-established HCC in vivo. Combined therapy caused an early and strong Th1-shift in the tumor environment as well as higher tumor apoptosis, leading to synergistic tumor regression of HCC. Thus, CD40L co-stimulation represents a promising tool for improving DC-based immunotherapy of HCC. |
