Journal: Oncogene

Article Title: Therapeutic efficacy of a DNA vaccine targeting the endothelial tip cell antigen delta-like ligand 4 in mammary carcinoma.

doi: 10.1038/onc.2010.176

Figure Lengend Snippet: Figure 1 Immunization with plasmid-encoded DLL4 results in an immunological response in BALB/c mice. (a) Expression of human DLL4 was verified by transient transfection of HeLa cells with empty vector or the vector encoding DLL4 (pDLL4) and analyzed by western blot. Recombinant human DLL4 was used as a positive control (rhDLL4). (b) Female BALB/c mice were immunized either intramuscularly (IM) or intradermally (ID) according to the depicted protocols. All intradermal injections were given in combination with electroporation (EP). One week after the final immunization animals were challenged by orthotopic injection of D2F2/E2 or TUBO cells in the mammary fat pad. (c) To investigate if the vaccination gave rise to an immunological response, serum was taken 10 days after the final immunization (protocol 1) and analyzed by human DLL4 enzyme-linked immunosorbent assay (ELISA). The figure depicts a representative analysis for one out of four mice analyzed.

Article Snippet: Plates were coated overnight at 4 1C with 2 pmol of recombinant human DLL4 (Bioinvent International, Lund, Sweden) or 1 pmol of recombinant mouse DLL4 (R&D Systems) per well in 50ml of 0.1M sodium carbonate, pH 9.5.

Techniques: Plasmid Preparation, Expressing, Transfection, Western Blot, Recombinant, Positive Control, Electroporation, Injection, Enzyme-linked Immunosorbent Assay

Journal: Oncogene

Article Title: Therapeutic efficacy of a DNA vaccine targeting the endothelial tip cell antigen delta-like ligand 4 in mammary carcinoma.

doi: 10.1038/onc.2010.176

Figure Lengend Snippet: Figure 2 DNA vaccination against DLL4 results in suppression of tumor growth in BALB/c mice. (a) Expression of DLL4 in D2F2/ E2 tumor endothelial cells was assessed by immunofluorescent staining for the endothelial markers, CD31 (red) and DLL4 (green). Cell nuclei were counterstained by DAPI (blue). Growth of orthotopically implanted D2F2/E2 (b and c) or TUBO (d) mammary carcinomas in BALB/c mice following immunization with empty vector or with DLL4 plasmid DNA according to protocol 1 (3 ID þ EP) or protocol 2 (2 IM, 1 ID þ EP; n ¼ 8 for all groups). The data shown in (b and d) are representative of three independent experiments. *Po0.05, **Po0.01; Student’s t-test.

Article Snippet: Plates were coated overnight at 4 1C with 2 pmol of recombinant human DLL4 (Bioinvent International, Lund, Sweden) or 1 pmol of recombinant mouse DLL4 (R&D Systems) per well in 50ml of 0.1M sodium carbonate, pH 9.5.

Techniques: Expressing, Staining, Plasmid Preparation

Journal: Oncogene

Article Title: Therapeutic efficacy of a DNA vaccine targeting the endothelial tip cell antigen delta-like ligand 4 in mammary carcinoma.

doi: 10.1038/onc.2010.176

Figure Lengend Snippet: Figure 3 Targeting DLL4 by vaccination results in excessive formation of nonfunctional blood vessels. (a) Visual inspection of excised D2F2/E2 tumors revealed overt thrombosis in tumors from DLL4-vaccinated mice. (b) Blood vessel density of D2F2/E2 tumors visualized by immunostaining for the endothelial cell marker CD31 (red; n ¼ 5 for each group). (c) Perfused blood vessels of D2F2/E2 tumors as determined by vascular perfusion using fluorescein-labeled tomato lectin (green; n ¼ 5 for each group). The total area of the vascular bed was visualized by immunostaining for CD31 (red; n ¼ 5 for each group). The fraction perfused area was expressed as perfused area divided by total vascular area for each field. (d) Apoptotic index of D2F2/E2 tumor cells as determined by immunostaining for activated caspase-3 (n ¼ 5 for each group). *Po0.05, **Po0.01; Student’s t-test.

Article Snippet: Plates were coated overnight at 4 1C with 2 pmol of recombinant human DLL4 (Bioinvent International, Lund, Sweden) or 1 pmol of recombinant mouse DLL4 (R&D Systems) per well in 50ml of 0.1M sodium carbonate, pH 9.5.

Techniques: Immunostaining, Marker, Labeling

Journal: Oncogene

Article Title: Therapeutic efficacy of a DNA vaccine targeting the endothelial tip cell antigen delta-like ligand 4 in mammary carcinoma.

doi: 10.1038/onc.2010.176

Figure Lengend Snippet: Figure 4 T cells are not mediators of the effector functions of the DLL4 vaccine. (a) Mouse DLL4-specific T cell responses following immunization by protocol 1 (3 ID þ EP) or protocol 2 (2 IM, 1 ID þ EP) were assessed by IFN-g ELISpot by stimulation of splenocytes with mouse DLL4 peptides or recombinant mouse extracellular portion of DLL4 (n ¼ 5 for each group). Recombinant carcinoembryonic antigen protein and carcinoembryonic antigen peptides were used as negative controls. The polyclonal stimulant concanavalin A (conA) was used as a positive control. The experiment was repeated three times. (b) Splenocyte activity in mice following immunization by protocol 1 (3 ID þ EP) or protocol 2 (2 IM, 1 ID þ EP) at the time of sacrifice after tumor challenge was assessed by IFN-g ELISpot without antigen-specific stimulation (vector, n ¼ 9; protocol 1, n ¼ 8; protocol 2, n ¼ 5). (c) Depletion of CD4 þ or CD8 þ cells was initiated three days before tumor challenge by injection of anti-CD4 or anti-CD8 antibodies and verified by flow cytometric analysis of peripheral blood 5 days after injection of antibodies. Tumor growth curve from vector-immunized mice was duplicated from Figure 2c, which depicts an experiment performed simultaneously to the T cell depletion experiment. (d) Growth of orthotopically implanted D2F2/E2 tumors in control mice and in mice depleted of CD4 þ/CD8 þ cells following vaccination with DLL4 plasmid DNA (n ¼ 6 for all groups). **Po0.01, ***Po0.001; Student’s t-test.

Article Snippet: Plates were coated overnight at 4 1C with 2 pmol of recombinant human DLL4 (Bioinvent International, Lund, Sweden) or 1 pmol of recombinant mouse DLL4 (R&D Systems) per well in 50ml of 0.1M sodium carbonate, pH 9.5.

Techniques: Enzyme-linked Immunospot, Recombinant, Positive Control, Activity Assay, Plasmid Preparation, Injection, Control

Journal: Oncogene

Article Title: Therapeutic efficacy of a DNA vaccine targeting the endothelial tip cell antigen delta-like ligand 4 in mammary carcinoma.

doi: 10.1038/onc.2010.176

Figure Lengend Snippet: Figure 5 Tumor growth suppression in DLL4-vaccinated mice is mediated by induction of anti-DLL4 antibodies. (a) The presence of anti-mouse DLL4 antibodies in the serum of DLL4-immunized mice was analyzed by ELISA. The figure depicts a representative analysis for one out of four mice analyzed. (b) IsolectinB4 staining of wholemounted P5 mouse retinas from mice treated with immune serum from vector or DLL4 immunized mice according to protocol 1 (3 ID þ EP; n ¼ 4 for each group). Arrowheads indicate endothelial cells morphologically identified as tip cells. (c) Growth of orthotopically implanted D2F2/E2 tumors in mice treated with serum from mice immunized with vector (n ¼ 12) or DLL4 plasmid DNA (n ¼ 16) according to protocol 1 (3 ID þ EP). The experiment was repeated twice with similar results. **Po0.01; Student’s t-test.

Article Snippet: Plates were coated overnight at 4 1C with 2 pmol of recombinant human DLL4 (Bioinvent International, Lund, Sweden) or 1 pmol of recombinant mouse DLL4 (R&D Systems) per well in 50ml of 0.1M sodium carbonate, pH 9.5.

Techniques: Enzyme-linked Immunosorbent Assay, Staining, Plasmid Preparation

Journal: Oncogene

Article Title: Therapeutic efficacy of a DNA vaccine targeting the endothelial tip cell antigen delta-like ligand 4 in mammary carcinoma.

doi: 10.1038/onc.2010.176

Figure Lengend Snippet: Figure 6 No evidence for liver toxicity or delayed wound healing following immunization with the DLL4 vaccine. (a) Hematoxylin and eosin staining of tissue sections of liver from mice that initiated the immunization procedure with empty vector or the DLL4 vaccine 5 months earlier. (b) Rate of healing expressed as % closure of wounds inflicted to mice immunized with empty vector or the DLL4 vaccine (n ¼ 8 mice per group, two wounds per mouse). *Po0.05, repeated-measures ANOVA.

Article Snippet: Plates were coated overnight at 4 1C with 2 pmol of recombinant human DLL4 (Bioinvent International, Lund, Sweden) or 1 pmol of recombinant mouse DLL4 (R&D Systems) per well in 50ml of 0.1M sodium carbonate, pH 9.5.

Techniques: Staining, Plasmid Preparation