Kumiko Shimozawa

Phase I clinical study of anti-apoptosis protein, survivin-derived peptide vaccine therapy for patients with advanced or recurrent colorectal cancer.

Survivin is a member of the inhibitor of apoptosis protein (IAP) family containing a single baculovirus IAP repeat domain. It is expressed during fetal development but becomes undetectable in terminally differentiated normal adult tissues. We previously reported that survivin and its splicing variant survivin-2B was expressed abundantly in various types of tumor tissues as well as tumor cell lines and was suitable as a target antigen for active-specific anti-cancer immunization. Subsequently, we identified an HLA-A24-restricted antigenic peptide, survivin-2B80-88 (AYACNTSTL) recognized by CD8+ cytotoxic T lymphocytes (CTLs). We, therefore, started a phase I clinical study assessing the efficacy of survivin-2B peptide vaccination in patients with advanced or recurrent colorectal cancer expressing survivin. Vaccinations with survivin-2B peptide were given subcutaneously six times at 14-day intervals. Of 15 patients who finished receiving the vaccination schedule, three suffered slight toxicities, including anemia (grade 2), general malaise (grade 1), and fever (grade 1). No severe adverse events were observed in any patient. In 6 patients, tumor marker levels (CEA and CA19-9) decreased transiently during the period of vaccination. Slight reduction of the tumor volume was observed in one patient, which was considered a minor responder. No changes were noted in three patients while the remaining eleven patients experienced tumor progression. Analysis of peripheral blood lymphocytes of one patient using HLA-A24/peptide tetramers revealed an increase in peptide-specific CTL frequency from 0.09% to 0.35% of CD8+ T cells after 4 vaccinations. This phase I clinical study indicates that survivin-2B peptide-based vaccination is safe and should be further considered for potential immune and clinical efficacy in HLA-A24-expression patients with colorectal cancer.

Phase I vaccination trial of SYT-SSX junction peptide in patients with disseminated synovial sarcoma

BackgroundSynovial sarcoma is a high-grade malignant tumor of soft tissue, characterized by the specific chromosomal translocation t(X;18), and its resultant SYT-SSX fusion gene. Despite intensive multimodality therapy, the majority of metastatic or relapsed diseases still remain incurable, thus suggesting a need for new therapeutic options. We previously demonstrated the antigenicity of SYT-SSX gene-derived peptides by in vitro analyses. The present study was designed to evaluate in vivo immunological property of a SYT-SSX junction peptide in selected patients with synovial sarcoma.MethodsA 9-mer peptide (SYT-SSX B: GYDQIMPKK) spanning the SYT-SSX fusion region was synthesized. Eligible patients were those (i) who have histologically and genetically confirmed, unresectable synovial sarcoma (SYT-SSX1 or SYT-SSX2 positive), (ii) HLA-A*2402 positive, (iii) between 20 and 70 years old, (iv) ECOG performance status between 0 and 3, and (v) who gave informed consent. Vaccinations with SYT-SSX B peptide (0.1 mg or 1.0 mg) were given subcutaneously six times at 14-day intervals. These patients were evaluated for DTH skin test, adverse events, tumor size, tetramer staining, and peptide-specific CTL induction.ResultsA total of 16 vaccinations were carried out in six patients. The results were (i) no serious adverse effects or DTH reactions, (ii) suppression of tumor progression in one patient, (iii) increases in the frequency of peptide-specific CTLs in three patients and a decrease in one patient, and (iv) successful induction of peptide-specific CTLs from four patients.ConclusionsOur findings indicate the safety of the SYT-SSX junction peptide in the use of vaccination and also give support to the property of the peptide to evoke in vivo immunological responses. Modification of both the peptide itself and the related protocol is required to further improve the therapeutic efficacy.

Clinical and immunological evaluation of anti-apoptosis protein, survivin-derived peptide vaccine in phase I clinical study for patients with advanced or recurrent breast cancer

BackgroundWe previously reported that survivin-2B, a splicing variant of survivin, was expressed in various types of tumors and that survivin-2B peptide might serve as a potent immunogenic cancer vaccine. The objective of this study was to examine the toxicity of and to c linically and immunologically evaluate survivin-2B peptide in a phase I clinical study for patients with advanced or recurrent breast cancer.MethodsWe set up two protocols. In the first protocol, 10 patients were vaccinated with escalating doses (0.1–1.0 mg) of survivin-2B peptide alone 4 times every 2 weeks. In the second protocol, 4 patients were vaccinated with the peptide at a dose of 1.0 mg mixed with IFA 4 times every 2 weeks.ResultsIn the first protocol, no adverse events were observed during or after vaccination. In the second protocol, two patients had induration at the injection site. One patient had general malaise (grade 1), and another had general malaise (grade 1) and fever (grade 1). Peptide vaccination was well tolerated in all patients. In the first protocol, tumor marker levels increased in 8 patients, slightly decreased in 1 patient and were within the normal range during this clinical trial in 1 patient. With regard to tumor size, two patients were considered to have stable disease (SD). Immunologically, in 3 of the 10 patients (30%), an increase of the peptide-specific CTL frequency was detected. In the second protocol, an increase of the peptide-specific CTL frequency was detected in all 4 patients (100%), although there were no significant beneficial clinical responses. ELISPOT assay showed peptide-specific IFN-γ responses in 2 patients in whom the peptide-specific CTL frequency in tetramer staining also was increased in both protocols.ConclusionThis phase I clinical study revealed that survivin-2B peptide vaccination was well tolerated. The vaccination with survivin-2B peptide mixed with IFA increased the frequency of peptide-specific CTL more effectively than vaccination with the peptide alone, although neither vaccination could induce efficient clinical responses. Considering the above, the addition of another effectual adjuvant such as a cytokine, heat shock protein, etc. to the vaccination with survivin-2B peptide mixed with IFA might induce improved immunological and clinical responses.

Prognostic significance of HLA class I expression in osteosarcoma defined by anti‐pan HLA class I monoclonal antibody, EMR8‐5

With the goal of establishing efficacious peptide‐based immunotherapy for patients with bone and soft tissue sarcomas, we previously identified the cytotoxic T lymphocyte‐defined osteosarcoma antigenic gene Papillomavirus binding factor. The present study was designed to determine the status of HLA class I expression in osteosarcoma and other bone and soft tissue sarcomas. Seventy‐four formalin‐fixed paraffin‐embedded specimens of various bone and soft tissue sarcomas, including 33 osteosarcomas, were stained with the anti‐HLA class I monoclonal antibody EMR8‐5, which we recently generated. The expression of HLA class I was lost or downregulated in 46 of these specimens (62%). With respect to osteosarcoma, loss or downregulation of HLA class I expression was seen in 13 (52%) of 25 primary tumors and seven (88%) of eight metastatic tumors. In six of 11 HLA class I‐negative osteosarcoma specimens, the expression of β‐2 microglobulin was also lost. Subsequently the prognostic significance of HLA class I expression was analyzed in 21 patients with osteosarcoma who had completed multidrug neoadjuvant chemotherapy and undergone adequate surgery. Patients with osteosarcoma highly expressing HLA class I showed significantly better overall and event‐free survival than those with HLA class I‐negative osteosarcoma. In contrast, such prognostic significance of HLA class I expression was not found in 15 patients with malignant fibrous histiocytoma of soft tissue. These findings suggest that the class I‐restricted cytotoxic T lymphocyte pathway plays a major role in immune surveillance of patients with osteosarcoma. (Cancer Sci 2006; 97: 1374–1380)

Identification of Human Autologous Cytotoxic T-Lymphocyte-Defined Osteosarcoma Gene That Encodes a Transcriptional Regulator, Papillomavirus Binding Factor

The prognosis for patients with osteosarcoma who do not respond to current chemotherapy protocols still remains poor. Toward the goal of establishing efficacious peptide-based immunotherapy for those patients, we previously developed an autologous pair of CTLs and an osteosarcoma cell line. In the current study, we screened the cDNA library of this osteosarcoma cell line using an autologous CTL clone and identified cDNA encoding an antigen. The isolated cDNA was identical to papillomavirus binding factor (PBF), which was recently reported as a DNA binding transcription factor cooperating with RUNX1. Reverse transcription-PCR analysis revealed that PBF was expressed in 16 of 19 cases of bone and soft-tissue sarcoma cell lines (5 of 6 of osteosarcoma lines) and 57 of 76 sarcoma tissue samples (11 of 14 of osteosarcoma tissues). Also, PBF was expressed in 10 of 13 epithelial cancer cell lines and 20 of 34 of cancer tissues. In contrast, PBF was detected in some normal organs including ovary, pancreas, spleen, and liver by reverse transcription-PCR but was restricted in the cytoplasm by immunostaining and undetectable by Western blotting. Furthermore, a 12-mer peptide, CTACRWKKACQR, located at the COOH terminus of PBF, was found to be a minimum requirement for recognition by the CTL clone in the context of the HLA-B*5502 molecule. These findings suggest that PBF is a shared tumor-associated antigen, which may serve as a source of peptides applicable to peptide-based immunotherapy for osteosarcoma and other malignant tumors.

Anti‐tumor Effect of Chemically Synthesized Sulfolipids Based on Sea Urchin's Natural Sulfonoquinovosylmonoacylglycerols

We recently reported that 3′‐sulfonoquinovosyl‐1′‐monoacylglycerol (designatedA‐5) extracted from sea urchin intestine was effective in suppressing the growth of solid tumors. Although the major fatty acid component of A‐5 was a saturated C16 acid, there were five other fatty acids, 14:0, 18:0, 14:1, 16:1, and 18:1, which constitute minor components of A‐5. Therefore, it remains unclear as to which of these six fatty acid components of A‐5 has the anti‐tumor effect. In this study, we synthesized sulfolipids each containing only one of these six fatty acids and tested their cytotoxicity against tumor cells and in vivo anti‐tumor effects on nude‐mice bearing solid tumors of human lung adenocarcinoma cell line A‐549. The IC50 values of all products against tumor cells were more than 10‐5M, suggesting weak cytotoxic activity compared with other chemotherapeutic compounds for cancer. On the other hand, in vivo anti‐tumor assay showed that sulfoquinovosyl‐monoacylglycerols (SQMG) composed of 14:1 and 18:1 (designated SQMG(14:1) and SQMG(18:1), respectively) were significantly effective in suppressing the growth of solid tumors. Our data suggested that these two SQMGs had a substantial anti‐tumor effect in vivo, and they are of interest as candidate drugs for anti‐cancer treatment.

An immunosuppressive effect by synthetic sulfonolipids deduced from sulfonoquinovosyl diacylglycerols of sea urchin.

Background. It is important to develop new immunosuppressive agents without clinical drawbacks. In this article, we reveal the possibility of a chemically synthetic sulfonolipid that acts as a novel immunosuppressive drug. Methods. We evaluated the immunosuppressive effect of 3-O-(6-deoxy-6-sulfono-&bgr;-D-glucopyranosyl)-1,2-di-O-acylglycerol (&bgr;-SQDG) that contains a saturated C18 fatty acid, which is designated as &bgr;-SQDG(18:0) by mixed lymphocyte reaction (MLR) and rat allogeneic skin graft. Then, we investigated the mechanism of immunosuppressive effect of &bgr;-SQDG(18:0). Results. &bgr;-SQDG(18:0) inhibited human MLR in a dose-dependent manner without overt cytotoxic effect and prolonged rat skin allograft rejection in vivo. &bgr;-SQDG(18:0) did not inhibit the direct activation of responder T. This reagent could not affect the expression of either major histocompatibility antigen complex (MHC) class I or class II molecules on the cell surface of the stimulator cells, antigen-presenting cells. In contrast, &bgr;-SQDG(18:0) was demonstrated to inhibit the binding among allogeneic lymphocytes. However, the expression of known cell surface accessory and adhesion molecules, such as CD4, CD28, leukocyte function-associated antigen 1, intercellular adhesion molecule 1, and CTLA-4, was not affected by &bgr;-SQDG(18:0) treatment. Conclusions. &bgr;-SQDG(18:0) might be a new class of the immunosuppressive reagent, and the inhibition of responder T-lymphocyte activation in MLR by &bgr;-SQDG(18:0) may be responsible for certain three-dimensional structures of this reagent or its quinovose binding to sulfonic acid.

Gene Expression Profile of Dorsal Root Ganglion in a Lumbar Radiculopathy Model

Study Design. DNA array analysis of dorsal root ganglion (DRG) using a rat model with nerve root constriction. Objective. To determine the molecular changes in the DRG adjacent to the injured nerve root in a lumbar radiculopathy model. Summary of Background Data. DNA array analysis in lumbar radiculopathy model has so far focused on the spinal dorsal horn. The molecular changes in the DRG adjacent to the injured nerve root in lumbar radiculopathy remain to be determined. Methods. Bilateral L5 DRGs were removed from 12 Sprague-Dawley rats on days 2, 7, 14, and 21 after nerve root ligation and on day 7 from 3 rats with sham operation. The aRNAs from the DRGs with nerve root ligation were labeled with Cy5 dye and those from the opposite side DRG (control) were labeled with Cy3 dye, and then hybridized to a 7793-spot Panorama Micro Array. It was considered to be significantly upregulated, when an average expression ratio of Cy5 to Cy3 was 2 or more. Genes upregulated were classified into early phase group (upregulated on day 2), midphase group (upregulated on days 7 and 14), and continuous group (upregulated from day 2 to 21). Seventeen genes were subjected to validation analysis with real-time quantitative PCR. Results. There were 16 upregulated genes in the early phase group, 56 genes in the midphase group, and 17 genes in the continuous group. Functional categorization revealed dominantly upregulated gene categories in each group; transcription/translation in the early phase group, enzyme/metabolism in the midphase group, and structure in the continuous group. Validation analysis of 17 genes demonstrated mean relative expression of 2.0 or more in all but 1 gene in the DRGs with nerve root ligation and none of them in the DRGs with sham operation. Conclusion. The genes identified in this study, especially those involved in pain signaling and inflammation, serve as potential targets for molecular-based therapy for lumbar radiculopathy.

Identification of Human Cytotoxic T-Lymphocyte-Defined Osteosarcoma Gene That Encodes a Transcriptional Regulator, Papillomavirus Binding Factor

THAT ENCODES A TRANSCRIPTIONAL REGULATOR, PAPILLOMAVIRUS BINDING FACTOR +*Tsukahara, T; *Nabeta, Y; *Kawaguchi, S; *Sato, Y; *Ida, K; *Nagoya, S; *Wada, T; ***Hiraga, H; **Ikeda, H; *Yamashita, T; **Sato, N +*Department of Orthopaedic Surgery, Sapporo Medical University, Sapporo, Japan. e-mail; tukahara@sapmed.ac.jp Introduction It is a great challenge to improve prognosis of patients with osteosarcomas who do not respond to current chemotherapy protocols. Peptide-based immunotherapy has brought about objective therapeutic responses in melanoma patients. However, such T -cell defined antigens have not been reported to date in osteosarcoma. Following attempts over a period of three years, we recently established an autologous tumor cell-CTL pair from a 16-year-old osteosarcoma patient (1). Using this pair, in the present study, we carried out cDNA library expression cloning and identified an antigen and an epitope, which sensitize the anti-autologous osteosarcoma CTL clone.

Development of Q-dot MHC/Peptide Multimer for Highly Sensitive Detection of Peptide-Specific T Cells

Sensitive Detection of Peptide-Specific T Cells Kumiko Shimozawa, Toshihiko Torigoe, Emiri Nakazawa, Noriyuki Sato. Cancer Vaccine Laboratory, Innovation Plaza Hokkaido, Japan Science and Technology Agancy, Sapporo, Japan; Pathology, Sapporo Medical University, Sapporo, Japan. Introduction: Tetrameric MHC/peptide complexes (teteramer) are important tools for detecting antigen-specific T cells. Tetramers are widely used to monitor immune responses in peptide vaccine therapies based on CTL-defined tumor antigens. However, frequencies of tetramer-positive CD8+ T cells in fresh peripheral blood mononuclear cells (PBMCs) are very low, and that makes it difficult to evaluate the effect of vaccination sequentially in individual cases. We developed novel MHC/peptide multimers using a new fluorescent nano-particle, QdotTM, which had strong fluorescence intensity. We compared the sensitivity and specificity of Qdot-multimer with those of PE-tetramer. Methods: Biotinylated MHC/peptide monomers were multimerized with Qdot655 -streptavidin. The peptides used for the multimers or the tetramers were TYGPVFMSL (HLA-A*2402 EBV LMP2) and RYLRDQQLLGI (HLA-A*2402 HIV envelop). PBMCs were stimulated with the EBV peptide in the presence of dendritic cells, and stained with Qdot-multimer or PEtetramer, and FITC-anti-CD8 antibody at room temperature. Results: EBV-Qdot-multimer was capable of detecting more EBV peptidespecific CD8+ T cells with high intensity than EBV-PE-tetramer. The peptide specificity of T cells was confirmed by using HIV-multimer or tetramer. Discussion: Our study indicated that Qdot-multimers were suitable for detecting peptide-specific CD8+ T cells with higher sensitivity than PE-tetramer. Qdot-multimers are now applied for the immunological monitoring in peptide vaccination therapy.