Cancer immunotherapy has experienced remarkable advances in the last decades. Striking clinical responses have been achieved for several solid cancers, particularly cancer types with a high... Show moreCancer immunotherapy has experienced remarkable advances in the last decades. Striking clinical responses have been achieved for several solid cancers, particularly cancer types with a high mutation burden, which placed tumour-mutated antigens (neoantigens) centre stage as targets of tumour immunity and cancer immunotherapy. Neoantigens can be presented in complex with HLA molecules on the tumour cell surface, where T cells with the correct specificity can recognize the neoantigen as ‘non-self’ which will trigger killing of the tumour cell by the T cell. In theory, cancers with a low/moderate mutation burden that present neoantigens in complex with HLA class molecules could still be eligible for T cell-mediated immunotherapy. This thesis, describes the finding that neoantigen-specific T cells are present in mismatch-repair proficient (MMR-p) colorectal cancer patients, a low mutation burden cancer type. Moreover, CD39 and CD103 were found as cell surface markers that pinpoint the T cell population that contains the neoantigen-specific T cells. In addition, subsequent metastasis of a melanoma patient cohort were studied and revealed that also at advanced, late-stage disease, neoantigen-directed T cell therapy is, in theory, still applicable. Taken together, the studies reveal potential for the development of neoantigen-directed cancer immunotherapy for a broader patient population. Show less
Lau, S.P.; Klaase, L.; Vink, M.; Dumas, J.; Bezemer, K.; Krimpen, A. van; ... ; Eijck, C.H.J. van 2022
Background: Pancreatic ductal adenocarcinoma (PDAC) is notorious for its poor prognosis even after curative resection. Responses to immunotherapy are rare and related to inadequate T-cell priming.... Show moreBackground: Pancreatic ductal adenocarcinoma (PDAC) is notorious for its poor prognosis even after curative resection. Responses to immunotherapy are rare and related to inadequate T-cell priming. We previously demonstrated the potency of allogeneic lysatedendritic cell (DC) vaccination in a preclinical model. Here we translate this concept to patients.Methods: In this phase I study, patients with resected PDAC were included when they demonstrated no radiologic signs of recurrence after standard-of-care treatment. Allogeneic tumour lysate-loaded autologous monocyte-derived DCs were injected at weeks 0, 2, 4 and at months 3 and 6. Objectives are feasibility, safety and immunogenicity of allogeneic tumour-DCs. The presence of tumour antigens shared between the vaccine and patient tumours was investigated. Immunological analyses were performed on peripheral blood, skin and tumour.Results: Ten patients were included. DC production and administration were successful. All patients experienced a grade 1 injection-site and infusion-related reaction. Two patients experienced a grade 2 fever and 1 patient experienced a grade 3 dyspnoea. No vaccine-related serious adverse events were observed. Shared tumour antigens were found between the vaccine and patient tumours. All evaluated patients displayed a vaccine-induced response indicated by increased frequencies of Ki67+ and activated PD-1+ circulating T-cells. In addition, treatment-induced T-c ell reactivity to autologous tumour of study patients was detected. Seven out of ten patients have not experienced disease recurrence or progression at a median follow-up of 25 months (15-32 months).Conclusion: Allogeneic tumour lysate-DC treatment is feasible, safe and induces immune reactivity to PDAC expressed antigens. 2022 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). 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
