Designing T-cells with desired T-cell receptor make-up for immunotherapy

TCR gene transfer is a strategy that enables the rapid engineering of anti-leukemic T-cells with defined specificity, resulting in a so called __off the shelf __ therapy. An elegant strategy to promote persistence of TCR modified T-cells may be TCR gene transfer into CMV- and EBV-specific T-cells, which exhibit proper memory and effector phenotypes. Furthermore, these virus-specific T-cells do not induce GvHD after HLA identical allo-SCT, and thus can be safely administered. For efficient anti-leukemic reactivity of the introduced TCR coinciding with enhanced in vivo survival, a balance between cell surface expression of the introduced and endogenous TCR is required. The aim of this thesis was to optimize the efficacy of TCR gene transfer, study possibilities and restrictions of virus-specific T-cells as host cells for TCR gene transfer and characterize the occurrence of potentially harmful mixed TCR dimers and strategies to prevent their formation.Dutch Cancer Society (KWF), J.E. Jurriaanse stichting, BD Biosciences, Beckman Coulter, Lonza.UBL - phd migration 201

Group changes in cognitive performance after surgery mask changes in individual patients with glioblastoma

Object:  There is a growing interest to include evaluations of cognitive performance in the clinical management of patients with Glioblastoma (GBM). However, as changes in cognitive performance of a group may mask changes in individual patients, study results are often difficult to transfer into clinical practice. We focused on the comparison of group versus individual changes in neuropsychological performance of GBM patients after initial surgical treatment. Methods:  Patients underwent neuropsychological evaluation using CNS Vital Signs one day prior to, and three months after surgery. Two-tailed paired samples t-tests were conducted to assess changes on the group level. Reliable Change Indices (RCIs), that correct for practice effects and imperfect test-retest reliabilities, were used to examine change in individual patients. Results:  Cognitive dysfunction was common (>80%) both before and three months after surgery in this sample of 82 GBM patients. Whereas group analyses revealed minimal changes in performance over time, RCIs demonstrated that most patients (89%) showed changes in performance in at least one cognitive domain. Half of these individual patients solely showed improvements, a quarter solely showed declines, and another quarter showed both improvements and declines. Conclusions:  This study clearly demonstrates that important individual changes in performance are masked when looking only at group results. Future studies should more often use an individual patient approach to enhance knowledge transfer into clinical practice

T cells expanded from renal cell carcinoma display tumor-specific CD137 expression but lack significant IFN-gamma, TNF-alpha or IL-2 production

Metastatic renal cell carcinoma (RCC) has a poor prognosis. Recent advances have shown beneficial responses to immune checkpoint inhibitors, such as anti-PD-1/PD-L1 antibodies. As only a subset of RCC patients respond, alternative strategies should be explored. Patients refractory to anti-PD-1 therapy may benefit from autologous tumor-infiltrating lymphocyte (TIL) therapy. Even though efficient TIL expansion was reported from RCC lesions, it is not well established how many RCC TIL products are tumor-reactive, how well they produce pro-inflammatory cytokines in response to autologous tumors, and whether their response correlates with the presence of specific immune cells in the tumor lesions. We here compared the immune infiltrate composition of RCC lesions with that of autologous kidney tissue of 18 RCC patients. Tcell infiltrates were increased in the tumor lesions, and CD8(+) Tcell infiltrates were primarily of effector memory phenotype. Nine out of 16 (56%) tested TIL products we generated were tumor-reactive, as defined by CD137 upregulation after exposure to autologous tumor digest. Tumor reactivity was found in particular in TIL products originating from tumors with ahigh percentage of infiltrated Tcells compared to autologous kidney, and increased CD25 expression on CD8(+) Tcells. Importantly, although TIL products had the capacity to produce the key effector cytokines IFN-gamma, TNF-alpha or IL-2, they failed to produce significant amounts in response to autologous tumor digests. In conclusion, TIL products from RCC lesions contain tumor-reactive Tcells. Their restricted tumor-specific cytokine production requires further investigation of immunosuppressive factors in RCC and subsequent optimization of RCC-derived TIL culture conditions.Immunobiology of allogeneic stem cell transplantation and immunotherapy of hematological disease

HA-1H T-cell receptor gene transfer to redirect virus-specific T cells for treatment of hematological malignancies after allogeneic stem cell transplantation: a phase 1 clinical study

Graft-vs.-leukemia (GVL) reactivity after HLA-matched allogeneic stem cell transplantation (alloSCT) is mainly mediated by donor T cells recognizing minor histocompatibility antigens (MiHA). If MiHA are targeted that are exclusively expressed on hematopoietic cells of recipient origin, selective GVL reactivity without severe graft-vs.-host-disease (GVHD) may occur. In this phase I study we explored HA-1H TCR gene transfer into T cells harvested from the HA-1H negative stem-cell donor to treat HA-1H positive HLA-A*02:01 positive patients with high-risk leukemia after alloSCT. HA-1H is a hematopoiesis-restricted MiHA presented in HLA-A*02:01. Since we previously demonstrated that donor-derived virus-specific T-cell infusions did not result in GVHD, we used donor-derived EBV and/or CMV-specific T-cells to be redirected by HA-1H TCR. EBV and/or CMV-specific T-cells were purified, retrovirally transduced with HA-1H TCR, and expanded. Validation experiments illustrated dual recognition of viral antigens and HA-1H by HA-1H TCR-engineered virus-specific T-cells. Release criteria included products containing more than 60% antigen-specific T-cells. Patients with high risk leukemia following T-cell depleted alloSCT in complete or partial remission were eligible. HA-1H TCR T-cells were infused 8 and 14 weeks after alloSCT without additional pre-conditioning chemotherapy. For 4/9 included patients no appropriate products could be made. Their donors were all CMV-negative, thereby restricting the production process to EBV-specific T-cells. For 5 patients a total of 10 products could be made meeting the release criteria containing 3-280 x 10(6)virus and/or HA-1H TCR T-cells. No infusion-related toxicity, delayed toxicity or GVHD occurred. One patient with relapsed AML at time of infusions died due to rapidly progressing disease. Four patients were in remission at time of infusion. Two patients died of infections during follow-up, not likely related to the infusion. Two patients are alive and well without GVHD. In 2 patients persistence of HA-1H TCR T-cells could be illustrated correlating with viral reactivation, but no overtin-vivoexpansion of infused T-cells was observed. In conclusion, HA-1H TCR-redirected virus-specific T-cells could be made and safely infused in 5 patients with high-risk AML, but overall feasibility and efficacy was too low to warrant further clinical development using this strategy. New strategies will be explored using patient-derived donor T-cells isolated after transplantation transduced with HA-1H-specific TCR to be infused following immune conditioning.Immunobiology of allogeneic stem cell transplantation and immunotherapy of hematological disease

Extracellular Domains of CD8 alpha and CD8ss Subunits Are Sufficient for HLA Class I Restricted Helper Functions of TCR-Engineered CD4(+) T Cells

Immunobiology of allogeneic stem cell transplantation and immunotherapy of hematological disease

Rapid Re-expression of Retrovirally Introduced Versus Endogenous TCRs in Engineered T cells After Antigen-specific Stimulation

To broaden the applicability of cellular immunotherapy, adoptive transfer of T-cell receptor (TCR) transferred T cells may be an attractive strategy. Using this approach, high numbers of defined antigen-specific T cells can be engineered. As the introduced TCR has to compete for cell surface expression with the endogenous TCR, the introduced TCR chains are under control of a strong viral promotor, which, in contrast to the endogenous promotor, is constitutively active. We examined whether this difference in regulation would result in differences in TCR internalization and re-expression of the introduced and endogenous TCR on dual TCR engineered T cells and the antigen-responsiveness of both the TCRs. We showed comparable TCR downregulation of TCRs expressed under regulation of a retroviral promotor or the endogenous promotor. However, the introduced TCRs were rapidly re-expressed on the cell surface after TCR stimulation. Despite rapid re-expression of the introduced TCR, T cells exerted similar antigen-sensitivity compared with control T cells, showing that cell mechanisms other than TCR cell surface expression are involved in antigen-sensitivity directly after antigen-specific stimulation. These results showed that TCR transduced T cells are functionally not different from nontransduced T cells and can potentially be used as an effective treatment strategy.Immunobiology of allogeneic stem cell transplantation and immunotherapy of hematological disease

Farmacokinetiek van coffeïne bij neonaten met apneu: Op weg naar verfijning van de dosering

We describe the influence of developmental, demographic and clinical determinants on caffeine pharmacokinetics in a multi-ethnic hospital population of 104 very premature infants. We also report on the incidence of apnoeas, bradycardias and desaturations and their relationship with measured serum caffeine levels. Caffeine pharmacokinetics/pharmacodynamics was studied retrospectively, utilizing therapeutic drug monitoring data from the first six weeks of neonatal life and data from the medical records. Retrospective analysis of therapeutic drug monitoring data can be utilized to make an estimate of the individual pharmacokinetic parameters based on population pharmacokinetics. With this technique, we were able to identify subgroups with deviating pharmacokinetics. The retrospective approach was not adequate to study pharmacodynamics, due to underreporting in the medical records

On the way to dosage refinement. Pharmacokinetics of caffeine in premature infants with apnoea

We describe the influence of developmental, demographic and clinical determinants on caffeine pharmacokinetics in a multi-ethnic hospital population of 104 very premature infants. We also report on the incidence of apnoeas, bradycardias and desaturations and their relationship with measured serum caffeine levels. Caffeine pharmacokinetics/pharmacodynamics was studied retrospectively, utilizing therapeutic drug monitoring data from the first six weeks of neonatal life and data from the medical records. Retrospective analysis of therapeutic drug monitoring data can be utilized to make an estimate of the individual pharmacokinetic parameters based on population pharmacokinetics. With this technique, we were able to identify subgroups with deviating pharmacokinetics. The retrospective approach was not adequate to study pharmacodynamics, due to underreporting in the medical records