Sandra Tuyaerts | KU Leuven (original) (raw)

Papers by Sandra Tuyaerts

Sarcoma, 2015

Uterine sarcomas are rare tumors accounting for 3,4% of all uterine cancers. Even after radical h... more Uterine sarcomas are rare tumors accounting for 3,4% of all uterine cancers. Even after radical hysterectomy, most patients relapse or present with distant metastases. The very limited clinical benefit of adjuvant cytotoxic treatments is reflected by high mortality rates, emphasizing the need for new treatment strategies. This review summarizes rising potential targets in four distinct subtypes of uterine sarcomas: leiomyosarcoma, low-grade and high-grade endometrial stromal sarcoma, and undifferentiated uterine sarcoma. Based on clinical reports, promising approaches for uterine leiomyosarcoma patients include inhibition of VEGF and mTOR signaling, preferably in combination with other targeted or cytotoxic compounds. Currently, the only targeted therapy approved in leiomyosarcoma patients is pazopanib, a multitargeted inhibitor blocking VEGFR, PDGFR, FGFR, and c-KIT. Additionally, preclinical evidence suggests effect of the inhibition of histone deacetylases, tyrosine kinase receptors, and the mitotic checkpoint protein aurora kinase A. In low-grade endometrial stromal sarcomas, antihormonal therapies including aromatase inhibitors and progestins have proven activity. Other potential targets are PDGFR, VEGFR, and histone deacetylases. In high-grade ESS that carry the YWHAE/FAM22A/B fusion gene, the generated 14-3-3 oncoprotein is a putative target, next to c-KIT and the Wnt pathway. The observation of heterogeneity within uterine sarcoma subtypes warrants a personalized treatment approach.

Journal of Immunotherapy, 2015

Survivin is an antiapoptotic protein, not expressed in terminally differentiated adult tissues, y... more Survivin is an antiapoptotic protein, not expressed in terminally differentiated adult tissues, yet overexpressed in several tumors. Therefore, it is an interesting target for immunotherapeutic strategies. In addition to specific overexpression in tumors, tumor survival is mediated by survivin and hence, tumor survival can be tackled by targeting survivin. Survivin expression in uterine cancer was validated by quantitative real-time polymerase chain reaction and immunohistochemistry. In addition, we evaluated survivin immunogenicity by analyzing spontaneous B-cell and T-cell responses in patients. Survivin as a protein was expressed in only a minority of normal tissues, whereas it was being expressed in all of the currently analyzed uterine cancers, both endometrial carcinoma (n=52) and uterine sarcoma (n=52). Survivin RNA transcripts were overexpressed in more aggressive tumors and survivin protein was overexpressed in recurrent endometrial tumors compared with primary tumors. Spontaneous T-cell responses were seen in 10/39 endometrial cancer patients and 3/16 uterine sarcoma patients. In normal controls, T-cell responses were found only in 1 donor (n=21). Although increased antibody titers were found in more aggressive and far-advanced tumors, no differences in B-cell responses were seen. Overall, when compared with normal controls, a B-cell response was only measured in 1/41 uterine sarcoma patients. In conclusion, we currently validated the presence of survivin in uterine cancer. In addition, spontaneous T-cell responses were found in 23.6% of the total patient population. These data indicate that a survivin-specific immune response may be induced spontaneously in patients, further fortifying the eligibility of survivin as an immunotherapeutic target.

Anticancer research, 2013

Treatment options are limited in uterine cancer, leading to a poor prognosis. Overexpression of W... more Treatment options are limited in uterine cancer, leading to a poor prognosis. Overexpression of Wilms' tumor gene 1 (WT1), the highest ranked tumor antigen, is attractive for immunotherapy. Six pre-treated patients with uterine cancer received four weekly vaccines of autologous dendritic cells (DCs) electroporated with WT1 mRNA. Safety, feasibility and immunogenicity were assessed. In cases of response, patients received monthly booster vaccines. The technique was feasible. One patient had a local allergic reaction. Three out of four Human Leucocyte Antigen-A2 (HLA-A2)-positive patients showed an oncological response; an enrichment of WT1-specific T-cells was observed in two of them. Two HLA-A2-negative patients did not show an oncological or an immunological response. A first series of six patients with uterine cancer treated with WT1 mRNA-electroporated DCs is presented herein. Oncological and immunological responses were observed and are supportive for further research.

Journal of reproductive immunology, Jan 8, 2015

Although described for the first time some decades ago, the contribution of the immune system to ... more Although described for the first time some decades ago, the contribution of the immune system to the establishment of tumors has not been extensively pursued for a long time. Over the last decade, however, more and more evidence has been accumulating concerning the role the immune system plays in tumor development and progression and its possible role in patient prognosis. In addition, interest is growing in preclinical and clinical research concerning the use of the immune system in the treatment of cancer. Immunotherapy for gynecological cancers in general, and for endometrial cancer in particular, is still in its infancy. Only a small number of studies, with varying success rates, have been published. Here, we provide a concise overview of the literature available on the role of the immune system in the normal endometrium and in endometrial cancer, in addition to the possible implications for future immunotherapeutic studies.

Human vaccines & immunotherapeutics, 2014

Uterine cancer is the most common pelvic gynecological malignancy. Uterine sarcomas and relapsed ... more Uterine cancer is the most common pelvic gynecological malignancy. Uterine sarcomas and relapsed uterine carcinomas have limited treatment options. The search for new therapies is urgent. Dendritic cell (DC) immunotherapy holds much promise, though has been poorly explored in uterine cancer. This commentary gives an insight in existing DC immunotherapy studies in uterine cancer and summarizes the possibilities and the importance of the loading of tumor antigens onto DC and their subsequent maturation. However, the sole application of DC immunotherapy to target uterine cancer will be insufficient because of tumor-induced immunosuppression, which will hamper the establishment of an effective anti-tumor immune response. The authors give an overview on the limited existing immunosuppressive data and propose a novel approach on DC immunotherapy in uterine cancer.

Anticancer research, 2013

Dendritic cell (DC)-based immunotherapy is an emerging new treatment option in ovarian cancer, an... more Dendritic cell (DC)-based immunotherapy is an emerging new treatment option in ovarian cancer, an important cause of cancer-related mortality. One patient with ovarian carcinosarcoma (OCS) and one with serous ovarian cancer (SOC) received four weekly vaccinations of autologous DCs electroporated with mRNA coding for the Wilms' tumor gene 1 (WT1). Safety, feasibility and immunogenicity were assessed. Vaccination was feasible without toxicity. In an ex vivo antigen re-stimulation assay of peripheral blood mononuclear cells, both patients showed increasing cluster of differentiation 137 (CD137+) antigen-specific T-cells and interleukin 10 (IL-10) production post-vaccination. Moreover, interleukin-2 (IL-2) production increased (OCS) as well as interferon-gamma (IFN-γ) and tumor necrosis factor-alpha (TNF-α) (SOC). Disease in patients progressed after four vaccines and patients continued with conventional therapies. After cessation of immunotherapy, they had an extended survival of 1...

Journal of immune based therapies and vaccines, 2011

2-3 September 2010, Brussels, BelgiumThe Dendritic Cell Therapy for Oncology Roundtable Conferenc... more 2-3 September 2010, Brussels, BelgiumThe Dendritic Cell Therapy for Oncology Roundtable Conference was organized by Reliable Cancer Therapies and moderated by Prof. Dr. Steven De Vleeschouwer. The organizer, Reliable Cancer Therapies, is a Swiss non-profit organization that provides information on evidence-based cancer treatments and funding for the development of a selection of promising cancer therapies. In order to be able to give valuable information about dendritic cell (DC) therapy to patients and physicians, the organizing committee felt it necessary to organize this conference to get an up-to-date status of the academic DC therapy field, collect ideas to guide patients towards clinical trials and to induce cross-fertilization for protocol optimization. In total, 31 experts participated to an in-depth discussion about the status and the future development path for dendritic cell vaccines. The conference started with general presentations about cancer immunotherapy, followed b...

Background / Purpose: Evaluation of the types of immune cells that infiltrate gynecological tumor... more Background / Purpose: Evaluation of the types of immune cells that infiltrate gynecological tumors. Main conclusion: Gynecological tumors contain a significant immune infiltrate, and the composition of this infiltrate is highly variable among different patients.

Background / Purpose: This poster describes the good manufaturing practice (GMP) of a dendritic c... more Background / Purpose: This poster describes the good manufaturing practice (GMP) of a dendritic cell (DC) vaccine electroporated with mRNA encoding both WT1 and survivin. Linked to dendritic cell-lysosomal-associated membrane protein (DC-LAMP) for helper T cell induction, and co-electroporated with TriMix mRNA (CD40L, CD70 and caTLR4) for DC maturation. We present results of the quality control of the vaccines and their capacity to induce T cell responses in vitro. Main conclusion: Monocyte-derived DCs could be succesfully electroporated with WT1-DC.LAMP or survivin-DC.LAMP and TriMix, leading to a highly mature phenotype and expression of the transgene. DCs from one tested donor were able to induce autologous survivin-specific T cells in vitro .

European Journal of Cancer, 2012

Cancer Immunology, Immunotherapy, 2014

arginase-1 activity in endometrial carcinomas compared with normal endometria, which was not the ... more arginase-1 activity in endometrial carcinomas compared with normal endometria, which was not the case for uterine sarcomas. Finally, we could demonstrate MDSC infiltration in fresh tumor suspensions from uterine tumors. these results indicate that the PD-1/PD-l1 interaction and B7-H4 could be possible targets for immune intervention in uterine cancer patients as well as mediation of MDSC function. these observations are another step toward the implementation of inhibitors of immunosuppression in the treatment of uterine cancer patients.

Methods in Molecular Biology, 2008

Antigen-loaded dendritic cells (DCs) have been intensively investigated as potential cellular ant... more Antigen-loaded dendritic cells (DCs) have been intensively investigated as potential cellular antitumor vaccines. Several recent reports have indicated that loading DCs with whole tumor derived mRNA or defined tumor-antigen-encoding mRNA represents an effective nonviral strategy to stimulate T cell responses both for in vitro and in vivo models. Here, we describe the electroporation method as a tool for introducing in vitro transcribed capped mRNA into human DCs for tumor vaccination. We use MART-1/Melan-A as a model tumor-associated antigen for the generation of a DC-based vaccine against melanoma cancer. In addition to efficient antigen loading, it is important to obtain a maximal number of potent antigen-presenting cells. Another prerequisite for the development of a DC-based cancer vaccine is to obtain mature DCs. In this chapter, we describe the basic techniques required for the successful genetic modification of DCs by using the mRNA electroporation method.

Cancer Gene Therapy, 2003

Genetically modified dendritic cells (DC) constitute a promising approach in cancer immunotherapy... more Genetically modified dendritic cells (DC) constitute a promising approach in cancer immunotherapy. Viral gene delivery systems have been shown to be very efficient strategies, but safety concerns for their clinical use in immunotherapy remain an important issue. Recently, the technique of mRNA electroporation was described as a very efficient tool for the genetic modification of human monocyte-derived DC. Here, we show that transgene expression can be modulated by varying the amount of mRNA used for electroporation. We document that CD40 ligation leads to a significant production of IL-12 by the electroporated DC, although the level of IL-12 production is somewhat lower than for non- or mock-electroporated DC. Furthermore, we show that the electroporated DC can be frozen and thawed without loss of viability or function and that Influenza virus Matrix Protein 1 mRNA electroporated DC are capable of inducing a memory cytotoxic T lymphocyte response and are more potent in doing so than mRNA-pulsed DC. Similar results were obtained with MelanA/MART-1 mRNA electroporated DC. These results clearly indicate that mRNA-electroporated DC represent powerful candidates for use as tumor vaccines and could constitute an improvement compared with vaccines using peptide-pulsed DC.

Cancer research, 2003

For the induction of an optimal immune response against cancer or infections not only CD8(+) CTLs... more For the induction of an optimal immune response against cancer or infections not only CD8(+) CTLs but also CD4(+) T helper cells must be induced, in particular IFN-gamma-secreting type 1 T helper cells. Several strategies have been explored to target tumor-associated antigens to the HLA class II processing compartments. We engineered a genetic construct encoding an invariant chain (Ii) protein where the CLIP region has been replaced by sequences encoding HLA class II-restricted MAGE-A3 epitopes. Monocyte-derived dendritic cells (DCs) were electroporated with in vitro transcribed mRNA encoding a modified Ii protein containing the HLA-DP4-restricted MAGE-A3 epitope. The capacity of these electroporated DCs to stimulate a MAGE-A3-specific T-cell clone was compared at different stages of DC maturation with the T-cell stimulatory capacity of DCs pulsed with the synthetic peptide. After electroporation, the T-cell stimulatory capacity was shown to be high and long lasting, whereas the sti...

Journal of Immunotherapy, 2011

The immunostimulatory capacity of dendritic cells is improved by co-electroporation with mRNA enc... more The immunostimulatory capacity of dendritic cells is improved by co-electroporation with mRNA encoding CD40 ligand, constitutively active toll-like receptor 4, and CD70 (TriMix-DC). This pilot clinical trial evaluated the feasibility, safety, and immunogenicity of a therapeutic vaccination containing autologous TriMix-DC co-electroporated with mRNA encoding a human leukocyte antigen class II-targeting signal linked to 1 of 4 melanoma-associated antigens (MAGE-A3, MAGE-C2, tyrosinase, and gp100) in patients with advanced melanoma. Thirty-five American Joint Committee on Cancer stage III/IV melanoma patients received autologous TriMix-DC (4 administrations 2 weeks apart). Immune monitoring was performed by evaluating skin biopsies of delayed type IV hypersensitivity (DTH) reactions for presence of vaccinal antigen-specific DTH-infiltrating lymphocytes (DIL). Thereafter, patients could receive interferon-alpha-2b (IFN-α-2b) 5 MU subcutaneously 3 times weekly and additional TriMix-DC every 8 weeks. TriMix-DC-related adverse events comprised grade 2 local injection site reactions (all patients), and grade 2 fever and lethargy (2 patients). Vaccinal antigen-specific DIL were found in 0/6 patients tested at vaccine initiation and in 12/21 (57.1%) assessed after the fourth vaccine. A positive postvaccination DTH test correlated with IL-12p70 secretion capacity of TriMix-DC. No objective responses to TriMix-DC alone were seen according to RECIST. Twenty-nine patients received IFN-α-2b after the fourth vaccine without unexpected adverse events. During TriMix-DC/IFN-α-2b combination therapy, 1 partial response and 5 stable disease (disease control of >6 months with regression of metastases) were observed in 17 patients with evaluable disease at baseline. In conclusion, this study demonstrated that therapeutic vaccination with autologous TriMix-DC is feasible, safe, and immunogenic and can be combined with sequential IFN-α-2b.

Clinical Cancer Research, 2009

Purpose: A critical factor determining the effectiveness of currently used dendritic cell (DC)-ba... more Purpose: A critical factor determining the effectiveness of currently used dendritic cell (DC)-based vaccines is the DC activation or maturation status. We have recently shown that the T-cell stimulatory capacity of DCs pulsed with tumor-antigen-derived peptides can be considerably increased by activating the DCs through electroporation with mRNA encoding CD40 ligand, CD70, and a constitutively active Toll-like receptor 4 (Tri-Mix DCs). Here, we investigate whether TriMix DCs can be coelectroporated with whole tumor-antigen-encoding mRNA. Experimental Design: The T-cell stimulatory capacity of TriMix DCs pulsed with the immunodominant MelanA-A2 peptide and that of TriMix DCs coelectroporated with Mel-anA mRNA were compared in vitro. TriMix DCs were also coelectroporated with mRNA encoding Mage-A3, Mage-C2, tyrosinase, or gp100. The capacity of these DCs to stimulate tumor-antigen-specific T cells in melanoma patients was investigated both in vitro before vaccination and after DC vaccination. Results: Like peptide-pulsed TriMix DCs, TriMix DCs coelectroporated with MelanA mRNA are very potent in inducing MelanA-specific CD8 + T cells in vitro. These T cells have an activated phenotype, show cytolytic capacity, and produce inflammatory cytokines in response to specific stimulation. TriMix DCs coelectroporated with tyrosinase are able to stimulate tyrosinase-specific CD8 + T cells in vitro from the blood of nonvaccinated melanoma patients. Furthermore, TriMix DCs coelectroporated with Mage-A3, Mage-C2, or tyrosinase are able to induce antigen-specific CD8 + T cells through therapeutic DC vaccination. Conclusions: TriMix DCs coelectroporated with whole tumor-antigen mRNA stimulate antigen-specific T cells in vitro and induce antigen-specific T-cell responses in melanoma patients through vaccination. Therefore, they represent a promising new approach for antitumor immunotherapy.

Methods in Molecular Biology, 2008

Antigen-loaded dendritic cells (DCs) have been intensively investigated as potential cellular ant... more Antigen-loaded dendritic cells (DCs) have been intensively investigated as potential cellular antitumor vaccines. Several recent reports have indicated that loading DCs with whole tumor derived mRNA or defined tumor-antigen-encoding mRNA represents an effective nonviral strategy to stimulate T cell responses both for in vitro and in vivo models. Here, we describe the electroporation method as a tool for introducing in vitro transcribed capped mRNA into human DCs for tumor vaccination. We use MART-1/Melan-A as a model tumor-associated antigen for the generation of a DC-based vaccine against melanoma cancer. In addition to efficient antigen loading, it is important to obtain a maximal number of potent antigen-presenting cells. Another prerequisite for the development of a DC-based cancer vaccine is to obtain mature DCs. In this chapter, we describe the basic techniques required for the successful genetic modification of DCs by using the mRNA electroporation method.

Sarcoma, 2015

Uterine sarcomas are rare tumors accounting for 3,4% of all uterine cancers. Even after radical h... more Uterine sarcomas are rare tumors accounting for 3,4% of all uterine cancers. Even after radical hysterectomy, most patients relapse or present with distant metastases. The very limited clinical benefit of adjuvant cytotoxic treatments is reflected by high mortality rates, emphasizing the need for new treatment strategies. This review summarizes rising potential targets in four distinct subtypes of uterine sarcomas: leiomyosarcoma, low-grade and high-grade endometrial stromal sarcoma, and undifferentiated uterine sarcoma. Based on clinical reports, promising approaches for uterine leiomyosarcoma patients include inhibition of VEGF and mTOR signaling, preferably in combination with other targeted or cytotoxic compounds. Currently, the only targeted therapy approved in leiomyosarcoma patients is pazopanib, a multitargeted inhibitor blocking VEGFR, PDGFR, FGFR, and c-KIT. Additionally, preclinical evidence suggests effect of the inhibition of histone deacetylases, tyrosine kinase receptors, and the mitotic checkpoint protein aurora kinase A. In low-grade endometrial stromal sarcomas, antihormonal therapies including aromatase inhibitors and progestins have proven activity. Other potential targets are PDGFR, VEGFR, and histone deacetylases. In high-grade ESS that carry the YWHAE/FAM22A/B fusion gene, the generated 14-3-3 oncoprotein is a putative target, next to c-KIT and the Wnt pathway. The observation of heterogeneity within uterine sarcoma subtypes warrants a personalized treatment approach.

Journal of Immunotherapy, 2015

Survivin is an antiapoptotic protein, not expressed in terminally differentiated adult tissues, y... more Survivin is an antiapoptotic protein, not expressed in terminally differentiated adult tissues, yet overexpressed in several tumors. Therefore, it is an interesting target for immunotherapeutic strategies. In addition to specific overexpression in tumors, tumor survival is mediated by survivin and hence, tumor survival can be tackled by targeting survivin. Survivin expression in uterine cancer was validated by quantitative real-time polymerase chain reaction and immunohistochemistry. In addition, we evaluated survivin immunogenicity by analyzing spontaneous B-cell and T-cell responses in patients. Survivin as a protein was expressed in only a minority of normal tissues, whereas it was being expressed in all of the currently analyzed uterine cancers, both endometrial carcinoma (n=52) and uterine sarcoma (n=52). Survivin RNA transcripts were overexpressed in more aggressive tumors and survivin protein was overexpressed in recurrent endometrial tumors compared with primary tumors. Spontaneous T-cell responses were seen in 10/39 endometrial cancer patients and 3/16 uterine sarcoma patients. In normal controls, T-cell responses were found only in 1 donor (n=21). Although increased antibody titers were found in more aggressive and far-advanced tumors, no differences in B-cell responses were seen. Overall, when compared with normal controls, a B-cell response was only measured in 1/41 uterine sarcoma patients. In conclusion, we currently validated the presence of survivin in uterine cancer. In addition, spontaneous T-cell responses were found in 23.6% of the total patient population. These data indicate that a survivin-specific immune response may be induced spontaneously in patients, further fortifying the eligibility of survivin as an immunotherapeutic target.

Anticancer research, 2013

Treatment options are limited in uterine cancer, leading to a poor prognosis. Overexpression of W... more Treatment options are limited in uterine cancer, leading to a poor prognosis. Overexpression of Wilms' tumor gene 1 (WT1), the highest ranked tumor antigen, is attractive for immunotherapy. Six pre-treated patients with uterine cancer received four weekly vaccines of autologous dendritic cells (DCs) electroporated with WT1 mRNA. Safety, feasibility and immunogenicity were assessed. In cases of response, patients received monthly booster vaccines. The technique was feasible. One patient had a local allergic reaction. Three out of four Human Leucocyte Antigen-A2 (HLA-A2)-positive patients showed an oncological response; an enrichment of WT1-specific T-cells was observed in two of them. Two HLA-A2-negative patients did not show an oncological or an immunological response. A first series of six patients with uterine cancer treated with WT1 mRNA-electroporated DCs is presented herein. Oncological and immunological responses were observed and are supportive for further research.

Journal of reproductive immunology, Jan 8, 2015

Although described for the first time some decades ago, the contribution of the immune system to ... more Although described for the first time some decades ago, the contribution of the immune system to the establishment of tumors has not been extensively pursued for a long time. Over the last decade, however, more and more evidence has been accumulating concerning the role the immune system plays in tumor development and progression and its possible role in patient prognosis. In addition, interest is growing in preclinical and clinical research concerning the use of the immune system in the treatment of cancer. Immunotherapy for gynecological cancers in general, and for endometrial cancer in particular, is still in its infancy. Only a small number of studies, with varying success rates, have been published. Here, we provide a concise overview of the literature available on the role of the immune system in the normal endometrium and in endometrial cancer, in addition to the possible implications for future immunotherapeutic studies.

Human vaccines & immunotherapeutics, 2014

Uterine cancer is the most common pelvic gynecological malignancy. Uterine sarcomas and relapsed ... more Uterine cancer is the most common pelvic gynecological malignancy. Uterine sarcomas and relapsed uterine carcinomas have limited treatment options. The search for new therapies is urgent. Dendritic cell (DC) immunotherapy holds much promise, though has been poorly explored in uterine cancer. This commentary gives an insight in existing DC immunotherapy studies in uterine cancer and summarizes the possibilities and the importance of the loading of tumor antigens onto DC and their subsequent maturation. However, the sole application of DC immunotherapy to target uterine cancer will be insufficient because of tumor-induced immunosuppression, which will hamper the establishment of an effective anti-tumor immune response. The authors give an overview on the limited existing immunosuppressive data and propose a novel approach on DC immunotherapy in uterine cancer.

Anticancer research, 2013

Dendritic cell (DC)-based immunotherapy is an emerging new treatment option in ovarian cancer, an... more Dendritic cell (DC)-based immunotherapy is an emerging new treatment option in ovarian cancer, an important cause of cancer-related mortality. One patient with ovarian carcinosarcoma (OCS) and one with serous ovarian cancer (SOC) received four weekly vaccinations of autologous DCs electroporated with mRNA coding for the Wilms' tumor gene 1 (WT1). Safety, feasibility and immunogenicity were assessed. Vaccination was feasible without toxicity. In an ex vivo antigen re-stimulation assay of peripheral blood mononuclear cells, both patients showed increasing cluster of differentiation 137 (CD137+) antigen-specific T-cells and interleukin 10 (IL-10) production post-vaccination. Moreover, interleukin-2 (IL-2) production increased (OCS) as well as interferon-gamma (IFN-γ) and tumor necrosis factor-alpha (TNF-α) (SOC). Disease in patients progressed after four vaccines and patients continued with conventional therapies. After cessation of immunotherapy, they had an extended survival of 1...

Journal of immune based therapies and vaccines, 2011

2-3 September 2010, Brussels, BelgiumThe Dendritic Cell Therapy for Oncology Roundtable Conferenc... more 2-3 September 2010, Brussels, BelgiumThe Dendritic Cell Therapy for Oncology Roundtable Conference was organized by Reliable Cancer Therapies and moderated by Prof. Dr. Steven De Vleeschouwer. The organizer, Reliable Cancer Therapies, is a Swiss non-profit organization that provides information on evidence-based cancer treatments and funding for the development of a selection of promising cancer therapies. In order to be able to give valuable information about dendritic cell (DC) therapy to patients and physicians, the organizing committee felt it necessary to organize this conference to get an up-to-date status of the academic DC therapy field, collect ideas to guide patients towards clinical trials and to induce cross-fertilization for protocol optimization. In total, 31 experts participated to an in-depth discussion about the status and the future development path for dendritic cell vaccines. The conference started with general presentations about cancer immunotherapy, followed b...

Background / Purpose: Evaluation of the types of immune cells that infiltrate gynecological tumor... more Background / Purpose: Evaluation of the types of immune cells that infiltrate gynecological tumors. Main conclusion: Gynecological tumors contain a significant immune infiltrate, and the composition of this infiltrate is highly variable among different patients.

Background / Purpose: This poster describes the good manufaturing practice (GMP) of a dendritic c... more Background / Purpose: This poster describes the good manufaturing practice (GMP) of a dendritic cell (DC) vaccine electroporated with mRNA encoding both WT1 and survivin. Linked to dendritic cell-lysosomal-associated membrane protein (DC-LAMP) for helper T cell induction, and co-electroporated with TriMix mRNA (CD40L, CD70 and caTLR4) for DC maturation. We present results of the quality control of the vaccines and their capacity to induce T cell responses in vitro. Main conclusion: Monocyte-derived DCs could be succesfully electroporated with WT1-DC.LAMP or survivin-DC.LAMP and TriMix, leading to a highly mature phenotype and expression of the transgene. DCs from one tested donor were able to induce autologous survivin-specific T cells in vitro .

European Journal of Cancer, 2012

Cancer Immunology, Immunotherapy, 2014

arginase-1 activity in endometrial carcinomas compared with normal endometria, which was not the ... more arginase-1 activity in endometrial carcinomas compared with normal endometria, which was not the case for uterine sarcomas. Finally, we could demonstrate MDSC infiltration in fresh tumor suspensions from uterine tumors. these results indicate that the PD-1/PD-l1 interaction and B7-H4 could be possible targets for immune intervention in uterine cancer patients as well as mediation of MDSC function. these observations are another step toward the implementation of inhibitors of immunosuppression in the treatment of uterine cancer patients.

Methods in Molecular Biology, 2008

Antigen-loaded dendritic cells (DCs) have been intensively investigated as potential cellular ant... more Antigen-loaded dendritic cells (DCs) have been intensively investigated as potential cellular antitumor vaccines. Several recent reports have indicated that loading DCs with whole tumor derived mRNA or defined tumor-antigen-encoding mRNA represents an effective nonviral strategy to stimulate T cell responses both for in vitro and in vivo models. Here, we describe the electroporation method as a tool for introducing in vitro transcribed capped mRNA into human DCs for tumor vaccination. We use MART-1/Melan-A as a model tumor-associated antigen for the generation of a DC-based vaccine against melanoma cancer. In addition to efficient antigen loading, it is important to obtain a maximal number of potent antigen-presenting cells. Another prerequisite for the development of a DC-based cancer vaccine is to obtain mature DCs. In this chapter, we describe the basic techniques required for the successful genetic modification of DCs by using the mRNA electroporation method.

Cancer Gene Therapy, 2003

Genetically modified dendritic cells (DC) constitute a promising approach in cancer immunotherapy... more Genetically modified dendritic cells (DC) constitute a promising approach in cancer immunotherapy. Viral gene delivery systems have been shown to be very efficient strategies, but safety concerns for their clinical use in immunotherapy remain an important issue. Recently, the technique of mRNA electroporation was described as a very efficient tool for the genetic modification of human monocyte-derived DC. Here, we show that transgene expression can be modulated by varying the amount of mRNA used for electroporation. We document that CD40 ligation leads to a significant production of IL-12 by the electroporated DC, although the level of IL-12 production is somewhat lower than for non- or mock-electroporated DC. Furthermore, we show that the electroporated DC can be frozen and thawed without loss of viability or function and that Influenza virus Matrix Protein 1 mRNA electroporated DC are capable of inducing a memory cytotoxic T lymphocyte response and are more potent in doing so than mRNA-pulsed DC. Similar results were obtained with MelanA/MART-1 mRNA electroporated DC. These results clearly indicate that mRNA-electroporated DC represent powerful candidates for use as tumor vaccines and could constitute an improvement compared with vaccines using peptide-pulsed DC.

Cancer research, 2003

For the induction of an optimal immune response against cancer or infections not only CD8(+) CTLs... more For the induction of an optimal immune response against cancer or infections not only CD8(+) CTLs but also CD4(+) T helper cells must be induced, in particular IFN-gamma-secreting type 1 T helper cells. Several strategies have been explored to target tumor-associated antigens to the HLA class II processing compartments. We engineered a genetic construct encoding an invariant chain (Ii) protein where the CLIP region has been replaced by sequences encoding HLA class II-restricted MAGE-A3 epitopes. Monocyte-derived dendritic cells (DCs) were electroporated with in vitro transcribed mRNA encoding a modified Ii protein containing the HLA-DP4-restricted MAGE-A3 epitope. The capacity of these electroporated DCs to stimulate a MAGE-A3-specific T-cell clone was compared at different stages of DC maturation with the T-cell stimulatory capacity of DCs pulsed with the synthetic peptide. After electroporation, the T-cell stimulatory capacity was shown to be high and long lasting, whereas the sti...

Journal of Immunotherapy, 2011

The immunostimulatory capacity of dendritic cells is improved by co-electroporation with mRNA enc... more The immunostimulatory capacity of dendritic cells is improved by co-electroporation with mRNA encoding CD40 ligand, constitutively active toll-like receptor 4, and CD70 (TriMix-DC). This pilot clinical trial evaluated the feasibility, safety, and immunogenicity of a therapeutic vaccination containing autologous TriMix-DC co-electroporated with mRNA encoding a human leukocyte antigen class II-targeting signal linked to 1 of 4 melanoma-associated antigens (MAGE-A3, MAGE-C2, tyrosinase, and gp100) in patients with advanced melanoma. Thirty-five American Joint Committee on Cancer stage III/IV melanoma patients received autologous TriMix-DC (4 administrations 2 weeks apart). Immune monitoring was performed by evaluating skin biopsies of delayed type IV hypersensitivity (DTH) reactions for presence of vaccinal antigen-specific DTH-infiltrating lymphocytes (DIL). Thereafter, patients could receive interferon-alpha-2b (IFN-α-2b) 5 MU subcutaneously 3 times weekly and additional TriMix-DC every 8 weeks. TriMix-DC-related adverse events comprised grade 2 local injection site reactions (all patients), and grade 2 fever and lethargy (2 patients). Vaccinal antigen-specific DIL were found in 0/6 patients tested at vaccine initiation and in 12/21 (57.1%) assessed after the fourth vaccine. A positive postvaccination DTH test correlated with IL-12p70 secretion capacity of TriMix-DC. No objective responses to TriMix-DC alone were seen according to RECIST. Twenty-nine patients received IFN-α-2b after the fourth vaccine without unexpected adverse events. During TriMix-DC/IFN-α-2b combination therapy, 1 partial response and 5 stable disease (disease control of >6 months with regression of metastases) were observed in 17 patients with evaluable disease at baseline. In conclusion, this study demonstrated that therapeutic vaccination with autologous TriMix-DC is feasible, safe, and immunogenic and can be combined with sequential IFN-α-2b.

Clinical Cancer Research, 2009

Purpose: A critical factor determining the effectiveness of currently used dendritic cell (DC)-ba... more Purpose: A critical factor determining the effectiveness of currently used dendritic cell (DC)-based vaccines is the DC activation or maturation status. We have recently shown that the T-cell stimulatory capacity of DCs pulsed with tumor-antigen-derived peptides can be considerably increased by activating the DCs through electroporation with mRNA encoding CD40 ligand, CD70, and a constitutively active Toll-like receptor 4 (Tri-Mix DCs). Here, we investigate whether TriMix DCs can be coelectroporated with whole tumor-antigen-encoding mRNA. Experimental Design: The T-cell stimulatory capacity of TriMix DCs pulsed with the immunodominant MelanA-A2 peptide and that of TriMix DCs coelectroporated with Mel-anA mRNA were compared in vitro. TriMix DCs were also coelectroporated with mRNA encoding Mage-A3, Mage-C2, tyrosinase, or gp100. The capacity of these DCs to stimulate tumor-antigen-specific T cells in melanoma patients was investigated both in vitro before vaccination and after DC vaccination. Results: Like peptide-pulsed TriMix DCs, TriMix DCs coelectroporated with MelanA mRNA are very potent in inducing MelanA-specific CD8 + T cells in vitro. These T cells have an activated phenotype, show cytolytic capacity, and produce inflammatory cytokines in response to specific stimulation. TriMix DCs coelectroporated with tyrosinase are able to stimulate tyrosinase-specific CD8 + T cells in vitro from the blood of nonvaccinated melanoma patients. Furthermore, TriMix DCs coelectroporated with Mage-A3, Mage-C2, or tyrosinase are able to induce antigen-specific CD8 + T cells through therapeutic DC vaccination. Conclusions: TriMix DCs coelectroporated with whole tumor-antigen mRNA stimulate antigen-specific T cells in vitro and induce antigen-specific T-cell responses in melanoma patients through vaccination. Therefore, they represent a promising new approach for antitumor immunotherapy.

Methods in Molecular Biology, 2008

Antigen-loaded dendritic cells (DCs) have been intensively investigated as potential cellular ant... more Antigen-loaded dendritic cells (DCs) have been intensively investigated as potential cellular antitumor vaccines. Several recent reports have indicated that loading DCs with whole tumor derived mRNA or defined tumor-antigen-encoding mRNA represents an effective nonviral strategy to stimulate T cell responses both for in vitro and in vivo models. Here, we describe the electroporation method as a tool for introducing in vitro transcribed capped mRNA into human DCs for tumor vaccination. We use MART-1/Melan-A as a model tumor-associated antigen for the generation of a DC-based vaccine against melanoma cancer. In addition to efficient antigen loading, it is important to obtain a maximal number of potent antigen-presenting cells. Another prerequisite for the development of a DC-based cancer vaccine is to obtain mature DCs. In this chapter, we describe the basic techniques required for the successful genetic modification of DCs by using the mRNA electroporation method.