Following the Anthrax bioterrorism attacks in the US in 2001, the Korean government established comprehensive countermeasures against bioterrorism. These measures included the government assuming management of all infectious agents that cause diseases, including smallpox, anthrax, plaque, botulism, and the causative agents of viral hemorrhagic fevers (ebola fever, marburg fever, and lassa fever) for national security. In addition, the Korean government is reinforcing the ability to prepare and respond to bioterrorism. Some of the measures being implemented include revising the laws and guidelines that apply to the use of infectious agents, the construction and operation of dual surveillance systems for bioterrorism, stockpiling and managing products necessary to respond to an emergency (smallpox vaccine, antibiotics, etc.) and vigorously training emergency room staff and heath workers to ensure they can respond appropriately. In addition, the government's measures include improved public relations, building and maintaining international cooperation, and developing new vaccines and drugs for treatments of infectious agents used to create bioweapons.
Anti-Infective Agents/supply & distribution ; Bacteria ; *Bioterrorism ; Disaster Planning/legislation & jurisprudence/*organization & administration ; Disease Notification/methods ; Disease Outbreaks/prevention & control ; Humans ; Korea ; Practice Guidelines as Topic ; *Sentinel Surveillance ; Vaccines/supply & distribution ; Viruses

To investigate the anti-vasculature effects and the anti-glioma effects of attenuated Salmonella typhimurium vaccine strain expressing VEGFR2 (flk-1) gene, plasmid pcDNA3.1-flk1 was constructed and electro-transfected into live attenuated Salmonella typhimurium strain SL7207. Mouse models of intracranial G1261 glioblastoma were treated with an orally administered attenuated Salmonella typhimurium expressing flk-1 gene. The survival period was recorded and vessel density was observed by immunofluorescence. CTLs activity was measured by MTT assay. Our results showed that attenuated Salmonella typhimurium vaccine strain expressing flk-1 gene could significantly inhibit glioblastoma growth, reduce vessel density, prolong the survival period and improve the survival rate in these mice. The flk-1 specific CTLs activity was increased obviously after the vaccination. Our study showed that attenuated Salmonella typhimurium vaccine strain expressing flk-1 gene could break peripheral immune tolerance a in glioma gainst this self-antigen and kill endothelial cells by the orally administered vaccine and can be used for both prophylactic and therapeutic purposes.
Angiogenesis Inhibitors ; pharmacology ; Animals ; Brain Neoplasms ; blood supply ; therapy ; Female ; Glioma ; blood supply ; therapy ; Mice ; Mice, Inbred C57BL ; Neovascularization, Pathologic ; Salmonella Vaccines ; immunology ; pharmacology ; Salmonella typhimurium ; immunology ; Transformation, Genetic ; Vaccines, Attenuated ; genetics ; immunology ; pharmacology ; Vascular Endothelial Growth Factor Receptor-2 ; genetics ; immunology

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

METHODSDendritic 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.

RESULTSDC-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.

CONCLUSIONImmunization 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.

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