[Anti-metastatic effect of vascular endothelial growth factor receptor 2 extracellular domain gene-modified dendritic cell vaccination in murine model with experimental pulmonary metastasis].

Abstract

OBJECTIVE:

To investigate the anti-metastatic effect of vascular endothelial growth factor receptor 2 extracellular domain gene-modified dendritic cell (DC-sVEGFR-2) vaccination.

METHODS:

Dendritic cells (DC) were electroporated with pcDNA3. 1/sVEGFR-2 plasmid DNA. Expression of sVEGFR-2 was determined by ELISA. For immunization, C57BL/6 mice were intravenously injected three times with 1 x 10(5) cells per mouse of DC, pcDNA3. 1-transfected DC (DC-vector) , DC-sVEGFR-2, or 100 microl of PBS at 7-day intervals. At 10 days after the last immunization, the immunized mice were subjected to assessment of cytotoxic T lymphocyte ( CTL) response to VEGFR-2, alginate bead analysis of tumor cell-induced angiogenesis, and observation of the anti-metastatic effect in B16 melanoma metastasis model. CTL activity was determined by a standard 4-h 51Cr release assay against VEGFR-2 + vascular endothelial cell line H5V, 3LL cells stably transfected with pcDNA3. 1/sVEGFR-2 (3LL,-sVEGFR-2), and VEGFR-2- cell lines EL-4 and 3LL. Monoclonal antibodies GK1.5 anti-CD4 and 2.43 anti-CD8 were used to deplete in vivo CD4 + T cells and CD8' T cells, respectively.

RESULTS:

DC-sVEGFR-2 could effectively express sVEGFR-2, whereas DC-vector and DC could not. Immunization of mice with DC-sVEGFR-2 significantly induce CTL activity against VEGFR-2 + cell lines H5V and 3LL-sVEGFR-2, however, no significant CTL activity was observed when VEGFR-2- syngeneic cell lines EL-4 and 3LL. were used as target cells, implying this CTL activity was VEGFR-2 specific. Alginate bead analysis of in vivo neoangiogenesis showed that the inhibition reached 50% in mice vaccinated with DC-sVEGFR-2 compared with mice vaccinated with DC, DC-vector or PBS. Anti-metastatic experiment showed that profound reduction in pulmonary metastases was found in mice immunized with DC-sVEGFR-2, while mice immunized with PBS, DC, DC-vector developed extensive pulmonary metastases. The number of tumor nodules on lung surface decreased by 81.9% in mice immunized with DC-sVEGFR-2 when compared with mice immunized with DC-vector (49.7+/-12.7 vs. 9.0+/-3.2). In vivo T cell subset depletion experiments showed that the anti-metastatic effect of DC-sVEGFR-2 vaccination was abrogated in CD8 + T cell-depleted but not in CD4+ T cell-depleted mice.

CONCLUSION:

Immunization of mice with DC-sVEGFR-2 could break self-tolerance and induce a significant CTL response to VEGFR-2, leading to profound inhibition of tumor-cell induced angiogenesis and metastasis. This anti-metastatic effect is mainly mediated by CD8+ T cells.

• Authors: Jian-ping Pan, Yue-song Weng, Qian-qian Wu
• Journal: Zhonghua zhong liu za zhi [Chinese journal of oncology] (Zhonghua Zhong Liu Za Zhi) Vol. 28 Issue 9 Pg. 646-9 (Sep 2006) ISSN: 0253-3766 [Print] China
• PMID: 17274366 (Publication Type: English Abstract, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Cancer Vaccines
• Vascular Endothelial Growth Factor Receptor-2

Topics

• Animals
• CD8-Positive T-Lymphocytes (immunology)
• Cancer Vaccines (immunology)
• Carcinoma, Lewis Lung (blood supply, immunology, pathology)
• Cell Line, Tumor
• Dendritic Cells (immunology, metabolism)
• Electroporation
• Female
• Immunotherapy, Adoptive (methods)
• Lung Neoplasms (secondary, therapy)
• Mice
• Mice, Inbred C57BL
• Neovascularization, Pathologic (immunology, therapy)
• T-Lymphocytes, Cytotoxic (immunology)
• Vascular Endothelial Growth Factor Receptor-2 (biosynthesis, genetics)