Osteosarcoma and Ewing sarcoma are the most common bone cancers in children and young adults. Despite advanced surgical techniques and multi-drug chemotherapy, patients with recurrent, metastatic... Show moreOsteosarcoma and Ewing sarcoma are the most common bone cancers in children and young adults. Despite advanced surgical techniques and multi-drug chemotherapy, patients with recurrent, metastatic or chemotherapy-resistant disease have a poor outcome. Thus, novel targeted therapies are needed that combine potent and specific anti-cancer activity with limited toxicity toward normal tissues. The thesis is introduced by an outline of the biological properties of osteosarcoma and Ewing sarcoma, followed by an overview of cancer immunology and immunotherapy with the primary focus on innate immunity of human natural killer (NK) cells and macrophages. In the research chapters, cellular interactions of NK cells and macrophages with bone tumor cells are characterized in order to achieve favorable effects on anti-cancer immune cell functions. It is demonstrated that the anti-cancer potential of especially NK cells but also macrophages can be enhanced and directed to the bone tumor cells. It is discussed that the modulation of tumor__immune cell interactions may help to design novel immunotherapeutic approaches to harness anti-cancer functions of innate immune cells against osteosarcoma and Ewing sarcoma. Show less
T cell responses against tumor-antigens are frequently observed for some human malignancies, in particular melanoma. However, the spontaneous development of T cell responses of a sufficient... Show moreT cell responses against tumor-antigens are frequently observed for some human malignancies, in particular melanoma. However, the spontaneous development of T cell responses of a sufficient strength to eradicate human malignancies is rare. The transfer of T cell receptor (TCR) __ genes into autologous T cells, a process called TCR gene transfer, allows one to engineer antigen-specific T cell responses of interest. Over the last decade, TCR gene transfer has progressed to the stage of clinical evaluation as a strategy to engineer T cell responses against tumor-antigens, in order to treat metastatic melanoma and other malignancies. The scope of the work in this thesis is to advance the development of TCR gene transfer as an engineering strategy for T cell immunity against cancer. This involves the assessment of the safety of TCR gene transfer, the evaluation of strategies to enhance the function of TCR-modified T cells in vivo, and the development of technologies to identify tumor-reactive TCR__ genes Show less
Melanoma is a malignancy that arises from melanocytes, the pigment-producing cells that can be predominantly found in the eye or the epidermal basal layer of the skin. Mainly due to increased UV... Show moreMelanoma is a malignancy that arises from melanocytes, the pigment-producing cells that can be predominantly found in the eye or the epidermal basal layer of the skin. Mainly due to increased UV exposure, the incidence of melanoma has doubled worldwide over the past three decades (200.000 new cases in 2008). Primary melanomas can be easily treated by surgical resection, leading to a good prognosis for stage I patients. However, metastasized melanoma is almost completely resistant to therapeutic modalities such as radio- and chemotherapy, resulting in a median overall survival of less than one year for this patient group. Despite considerable efforts, for over 20 years there was no melanoma treatment developed that could improve survival of stage IV patients. However, the treatment of unresectable metastasized melanoma has progressed markedly in recent years due to the development of both immunotherapies that stimulate anti-tumor immunity and targeted therapies that block oncogenic proteins. This thesis will focus on pre-clinical work concerning the optimization of melanoma treatment. In detail, it will address for both targeted therapies and immunotherapies factors that play a role in the identification of response-predictive biomarkers, the toxicity of treatments, and the potential efficacy of combination treatments. Show less
Clinical studies demonstrated that HLA-DPB1 mismatched stem cell transplantation (SCT) is associated with a decreased risk of disease relapse and an increased risk of graft versus host disease ... Show moreClinical studies demonstrated that HLA-DPB1 mismatched stem cell transplantation (SCT) is associated with a decreased risk of disease relapse and an increased risk of graft versus host disease (GVHD) compared to HLA-DPB1 matched SCT. In T-cell depleted SCT, mismatching of HLA-DPB1 was not associated with an increased risk of severe GVHD, whereas a significant decreased risk of disease relapse was still observed. In this thesis we showed that HLA-DPB1 mismatched allo-SCT followed by donor lymphocyte infusion (DLI) late after transplantation can result in selective graft versus leukemia (GVL) reactivity. Although several studies have suggested that some HLA-DPB1-mismatches were less immunogenic, we demonstrated that all HLA-DPB1-mismatches as defined by allele typing are immunogenic and resulted in vitro in high frequency immune responses. Finally, in a cohort of 24 patients transplanted for various hematological ma lignancies with a 10 out 10 matched HLA-DPB1 mismatched SCT followed by DLI, HLA-DP specific immune responses were frequently found. The presence of HLA-DP specific CD4+ T cells correlated with clinical immune responses including both selective GVL-reactivity and GVHD. It is likely that in each individual local environmental circumstances possibly in combination with the induction of other immune responses may finally determine the balance between GVHD and GVL-reactivity HLA-DP HLA-class II mismatch alloreactivity hematopoietic stem cell transplantation donor lymphocyte infusion graft versus host disease graft versus leukemia reactivity immunotherapy Show less
Sonderen, A. van; Wirtz, P.W.; Verschuuren, J.J.G.M.; Titulaer, M.J. 2013
This dissertation reports on the relation between the immune system, colorectal cancer and immunotherapy. In the first part, expression of HLA class I and expression of CXCL5 in colocectal cancer... Show moreThis dissertation reports on the relation between the immune system, colorectal cancer and immunotherapy. In the first part, expression of HLA class I and expression of CXCL5 in colocectal cancer was studied. Low expression of HLA class I in rectal tumors was associated with poor survival of rectal cancer patients. Low expression of CXCL5 in cancer cells was significantly associated with poor prognosis in a population of colorectal cancer patients and correlated with presence of intra-tumoral CD8+ T-cell infiltration. In the second part of this thesis we focused on induction of tumor specific T-cells. For immunotherapeutic purposes distinction should be made between microsatellite instable (MSI-H) and microsatellite stable (MSS) colorectal tumors, as MSI-H tumors express neo-antigens __foreign__ to the immune system while immunotherapy against MSS tumors depends on tumor associated __self__-antigens. We developed a methodology predicting immunogenic behavior of frameshift-mutated antigens present in MSI-H tumors that was based on accumulation and MHC class I presentation. This method can be used to develop cancer immunotherapy of patients at risk for MSI-H tumors. In the last two chapters we described safety and immunogenicity of a p53 synthetic long peptides vaccine combined with and without Interferon-alpha. Addition of IFN-_ to the p53-SLP_ vaccine significantly improved p53-specific after vaccination. Altogether this dissertation reports on the relation between the immune system, colorectal cancer and immunotherapy. This knowledge can be used to further optimize immunotherapeutic strategies to treat cancer patients. Show less
Human leukocyte antigen (HLA) matched allogeneic stem cell transplantation (SCT) is an established curative treatment for hematopoietic malignancies and an investigative immunotherapeutic approach... Show moreHuman leukocyte antigen (HLA) matched allogeneic stem cell transplantation (SCT) is an established curative treatment for hematopoietic malignancies and an investigative immunotherapeutic approach for solid tumors. The curative effect of allogeneic SCT is based on so called graft versus-tumor (GvT) responses. The GvT effect in the HLA-matched setting is mainly driven by donor immune responses against so called minor histocompatibility antigens (mHags). Emerging data suggest that immunotherapy targeting mHags may eradicate cancer without severe side effects. This thesis investigated 1) the proof of concept for the efficacy of mHag specific immunotherapy in vitro and in vivo, 2) the optimal circumstances under which mHag specific cytotoxic T-cells (CTLs) are most effective against established leukemia and solid tumors, 3) new immune escape mechanisms in cancer that need to be considered when targeting mHags, 4) the optimal protocols for the in vitro expansion of mHags CTLs, 5) the optimal design of mHag peptide vaccines and 6) the optimal parameters for the clinical guidance of mHags specific immunotherapy of cancer. The data acquired in this thesis have provided relevant knowledge that is already partially implemented in the design of new HA-1 vaccination studies aiming at curing leukemia and solid tumors. Show less
Steenwijk, P.J.D. van; Ramwadhdoebe, T.H.; Lowik, M.J.G.; Minne, C.E. van der; Berends-van der Meer, D.M.A.; Fathers, L.M.; ... ; Burg, S.H. van der 2012
In this thesis, we report on various aspects of tumor - host (immune) interactions in Ewing sarcoma patients with the aim to obtain leads for immunotherapeutic or targeted treatment strategies. We... Show moreIn this thesis, we report on various aspects of tumor - host (immune) interactions in Ewing sarcoma patients with the aim to obtain leads for immunotherapeutic or targeted treatment strategies. We demonstrate a key role for interferon gamma (IFNg) in enhancing both Ewing sarcoma immunogenicity and susceptibility to cytotoxicity. An (endogenous) pro-inflammatory tumor microenvironment consisting of cytotoxic T-lymphocytes and IFNg-inducible chemokines provides prognostic benefit. Moreover, despite evidence for immunologic pressure in selection of HLA class I loss variants, intact IFNg-inducibility of the HLA class I antigen processing machinery emphasizes the significance of a pro-inflammatory microenvironment for initiation/ execution of adaptive anti-tumor immunity. Pre-clinical support for the potential of adoptive cell transfer therapies, in particular combinatorial natural killer cell-based therapy, is provide d. Sensitization of Ewing sarcoma by conventional or targeted therapies, including histone deacetylase inhibitors, combined with cytokine activation of natural killer cells enhances anti-tumor responses and overcomes both intrinsic functional natural killer cell defects as well as cross-resistance of chemotherapy-resistant Ewing sarcoma to natural killer cells. Finally, due to a crucial role of the CXCR4-CXCL12 axis in Ewing sarcoma progression, disruption of this axis by a CXCR4-specific antagonist may represent a promising treatment option for patients with Ewing sarcoma. Show less
The immune system plays an important role in the balance between viral clearance and viral persistence in HPV related (pre)malignant lesions. In this thesis, we analyzed HPV clade A9-specific T... Show moreThe immune system plays an important role in the balance between viral clearance and viral persistence in HPV related (pre)malignant lesions. In this thesis, we analyzed HPV clade A9-specific T-cell responses in relation to virological and clinical outcome to gain further insight into HPV-specific cellular immunity in relation to the natural course of disease. In depth analysis of cellular immune responses against the E6 antigen of HPV16 and the closely related members of clade A9 (HPV31, 33, 35, 52 and 58) showed us that HPV-specific cross-reactive CD4+ T cells are rare and unlikely to mediate cross protection (chapter 2). The clinical course of cervical HPV infection and HPV-specific immune responses in prospective studies are described in chapter 4 and 5. In those chapters, a strong correlation is observed between a persistent HPV infection or progressive disease and the lack or failure of a type-specific immune response (>90% of the cases). No correlation is detected between HPV type-specific cellular immune responses and virological clearance of the infection and HPV type-specific immunity may be associated with clearance of a cervical HPV induced lesion (chapter 4 and 5). Interestingly, a statistically significant trend could be detected between the presence of a type-specific immunity (HPV16E2) and regression of a low-grade lesion (chapter 5). A similar, but - due to small number of patients __ not statistically significant trend was observed in chapter 4. Together, this suggests that the local innate immune system might play a role in the clearance of transient infections, whereas the cellular immune response can play a role in regression of histologically proven HPV induced lesions. Detection of HPV16 type-specific cellular immune responses in vivo, by the use of a DTH skin test, confirmed that cellular immune responses in healthy subjects consist of both HPV-specific CD4+ Th1/Th2 and CD8+ T cells (chapter 3). Show less
This dissertation deals with the role of local immune stimulation in the lymph node and tumor microenvironment and its effect on systemic CD8+ T cell responses, in particular the anti-tumor CD8+ T... Show moreThis dissertation deals with the role of local immune stimulation in the lymph node and tumor microenvironment and its effect on systemic CD8+ T cell responses, in particular the anti-tumor CD8+ T cell responses. In chapter 2 the use of a slow-release system is described to deliver the immune-activating agonistic CD40 antibody to the tumor-draining area, and the advantages of this method over systemic administration of the antibody. The local, slow-release administration was very effective in activating a systemic anti-tumor effector CD8+ T cell response, to such an extent that a tenfold lower dose of antibody could be used without loss of efficacy. Adverse side-effects, analyzed by organ histology and liver enzymes in the blood, were much lower upon local anti-CD40 antibody delivery compared to systemic administration. The local delivery of anti-CD40 antibody resulted in a systemic anti-tumor CD8+ T cell response, capable of clearing distant tumors expressing identical tumor antigens. Chapter 3 shows that slow-release local administration of CTLA-4 blocking antibody can also activate a tumor-specific CD8+ T cell response and cause tumor regression, while lowering systemic adverse side-effect as compared to systemic administration. CTLA-4 blocking antibody is being widely used in clinical trials, and its use has been complicated by induction of auto-immune disease. Here we show that using a local low dose injection of CTLA-4 blocking antibody in a slow-release formulation is equally effective in activating a tumor-specific CD8+ T cell response, capable of eradicating tumor cells as systemic high dose treatment. The influence of local lymph node activation on systemic T cell responses is further analyzed in chapter 4. CD8+ T cell priming generally occurs in a locally inflamed lymph node, called a reactive LN, due to the presence of pathogens. The role of the inflammatory milieu on the priming and fate of CD8+ T cells was studied by separating the TCR-MHC interaction from the inflammatory cues, by priming briefly in vitro followed by transfer to mice with or without a CpG-induced reactive lymph node. The primary CD8+ T cell response was not influenced by the presence of a reactive lymph node, however, after a boost vaccination in the memory phase, CD8+ T cells primed in the presence of a reactive LN displayed a strong quantitative advantage over control CD8+ T cells. The reactive LN, which remained swollen with enhanced cellularity for a pronounced period of time, was envisaged to act as a shelter for CD8+ T cells while undergoing contraction after the primary response. In chapter 5, the advantages and disadvantages of the use of dextran-based microparticles as slow-release system for the delivery of immune-activating antibodies such as agonistic CD40 in the tumor-draining area are described. Dextran-based microparticles can be tailored to release antibodies in desired pharmacokinetics, leading to an even further decrease of adverse side-effects, as compared to previously described Montanide-ISA 51. However, dextran-based particles were unexpectedly found to have a stimulating effect on tumor-outgrowth. This effect coincided with the appearance of large, ulcerated swellings at the site of injection. In chapter 6, the issues presented in this thesis are discussed. The knowledge gained in the work shown here, compared with and strengthened by related published work, is used to state the opinion that targeting the tumor-draining lymph node and/or tumor microenvironment for immune-activating therapy against tumors must be seriously considered. Show less
For the successful application of immunotherapy for leukemia significant numbers of viable T cells with the right antigen specificity have to be available within a limited period of time. TCR gene... Show moreFor the successful application of immunotherapy for leukemia significant numbers of viable T cells with the right antigen specificity have to be available within a limited period of time. TCR gene transfer is a promising strategy enabling the generation of large numbers of T cells with a selective antigen specificity, while reducing the time required for in vitro culture. Future clinical application of TCR engineered T cells may result in an off-the-shelf therapy with TCRs suitable for large numbers of patients. Acquisition of more insight into the possibilities and restrictions of TCR gene transfer and assessment of the efficacy of the therapeutic cells may provide a solid basis for clinical application in the near future. However, the application of immunotherapy for hematological malignancies is currently limited by the restricted number of hematopoiesis specific mHags that can be used as target antigens. Furthermore, an important issue for clinical implementation of TCR gene therapy is the prevention of the formation of mixed TCR dimers, which have recently been shown to induce autoreactivity. In addition, the future development of TCR gene therapy strategies will benefit from increased knowledge about both the T cells that serve as host cell for TCR gene transfer and other T cells present in the patient that may manipulate the immunotherapeutic responses of the TCR engineered T cells. Unfortunately, function analysis of T cell populations using biologically relevant antigens is hampered by the large number of different T cell specificities present and the difficulty to identify the specificity of T cells. The aim of this thesis was to characterize novel T cell populations that may serve as host cells for TCR gene transfer and to determine their possibilities and restrictions as TCR engineered immunotherapeutic effector cells for the treatment of hematological malignancies. Show less
