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Pediatric patients with recurrent, refractory or advanced soft tissue sarcoma (STS) who are simultaneously showing signs of cumulative treatment toxicity are in need of novel therapies. In this preclinical analysis, we identified ErbB2 as a targetable antigen on STS cells and used cytokine-induced killer (CIK) cells transduced with the lentiviral 2nd-generation chimeric antigen receptor (CAR) vector pS-5.28.z-IEW to target ErbB2-positive tumors. Solely CIK cell subsets with the CD3+ T cell phenotype showed up to 85% cell surface expression of the respective CAR. A comparison of wildtype (WT), mock-vector and ErbB2-CAR-CIK cells showed, that engineered cells exhibited diminished in vitro expansion, retained WT CIK cell phenotype with higher percentages of differentiated effector memory/effector cells. Activating natural killer (NK) cell receptor NKG2D-restricted target cell recognition and killing of WT and ErbB2-CAR-CIK cells was maintained against ErbB2-negative tumors, while ErbB2-CAR-CIK cells demonstrated significantly increased cytotoxicity against ErbB2-positive targets, including primary tumors. ErbB2-CAR- but not WT CIK cells proliferated, infiltrated and efficiently lysed tumor cell monolayers as well as 3D tumor spheroids.
Here, we demonstrate a potential cell therapeutic approach using ErbB2-CAR-CIK cells for the recognition and elimination of tumor cells expressing ErbB2, which we identified as a targetable antigen on high-risk STS cells.
Natural killer (NK) cells play an important role following allogeneic hematopoietic stem cell transplantation (HSCT) exerting graft-versus-leukemia/tumor effect and mediating pathogen-specific immunity. Although NK cells are the first donor-derived lymphocytes reconstituting post-HSCT, their distribution of CD56++CD16− (CD56bright), CD56++CD16+ (CD56intermediate=int), and CD56+CD16++ (CD56dim) NK cells is explicitly divergent from healthy adults, but to some extent comparable to the NK cell development in early childhood. The proportion of CD56bright/CD56int/CD56dim changed from 15/8/78% in early childhood to 6/4/90% in adults, respectively. Within this study, we first compared the NK cell reconstitution post-HSCT to reference values of NK cell subpopulations of healthy children. Afterward, we investigated the reconstitution of NK cell subpopulations post-HSCT in correlation to acute graft versus host disease (aGvHD) and chronic graft versus host disease (cGvHD) as well as to viral infections. Interestingly, after a HSCT follow-up phase of 12 months, the distribution of NK cell subpopulations largely matched the 50th percentile of the reference range for healthy individuals. Patients suffering from aGvHD and cGvHD showed a delayed reconstitution of NK cells. Remarkably, within the first 2 months post-HSCT, patients suffering from aGvHD had significantly lower levels of CD56bright NK cells compared to patients without viral infection or without graft versus host disease (GvHD). Therefore, the amount of CD56bright NK cells might serve as an early prognostic factor for GvHD development. Furthermore, a prolonged and elevated peak in CD56int NK cells seemed to be characteristic for the chronification of GvHD. In context of viral infection, a slightly lower CD56 and CD16 receptor expression followed by a considerable reduction in the absolute CD56dim NK cell numbers combined with reoccurrence of CD56int NK cells was observed. Our results suggest that a precise analysis of the reconstitution of NK cell subpopulations post-HSCT might indicate the occurrence of undesired events post-HSCT such as severe aGvHD.values
Background: Computed-tomography-guided interventions are attractive for tissue sampling of paediatric tumor lesions; however, it comes with exposure to ionizing radiation. The aim of this study was to analyse the radiation dose, accuracy and speed of CT-guided interventions in paediatric patient cohort.
Methods: We retrospectively reviewed CT-guided interventions over a 10 -year period in 65 children. The intervention site consisted of bones in 38, chest (lung) in 15 and abdomen (liver, lymph nodes) in 12 cases. Radiation dose and duration of the procedures were analysed. The statistical analysis was performed using dedicated statistical software (BiAS 8.3.6 software, Epsilon Verlag, North Hasted).
Results: All interventions were performed successfully. Mean target access path to lesion within the patients was 6.0 cm (min 3.5 cm, max 11.2 cm). Time duration to complete intervention was 25:15 min (min 17:03 min, max 43:00 min). The dose-length product (DLP) of intervention scan was 29.5 mGy · cm (min 6 mGy · cm, max 85 mGy · cm) with the lowest dose for biopsies in the region of the chest (p = 0.04).
Conclusions: With justified indications, CT-guided paediatric interventions are safe, effective and can be performed both, with short intervention times and low radiation exposure.
Rhabdomyosarcoma (RMS), the most common cancer of connective tissues in pediatrics, is often resistant to conventional therapies. One underlying mechanism of this resistance is the overexpression of Inhibitor of Apoptosis (IAP) proteins, leading to a dysfunctional cell death program within tumor cells. Smac mimetics (SM) are small molecules that can reactivate the cell death program by antagonizing IAP proteins and thereby compensating their overexpression. Here, we report that SM sensitize two RMS cell lines (RD and RH30) toward natural killer (NK) cell-mediated killing on the one hand, and increase the cytotoxic potential of NK cells on the other. The SM-induced sensitization of RH30 cells toward NK cell-mediated killing is significantly reduced through blocking tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) on NK cells prior to coculture. In addition, the presence of zVAD.fmk, a pancaspase inhibitor, rescues tumor cells from the increase in killing, indicating an apoptosis-dependent cell death. On the NK cell side, the presence of SM in addition to IL-2 during the ex vivo expansion leads to an increase in their cytotoxic activity against RH30 cells. This effect is mainly TNFα-dependent and partially mediated by NK cell activation, which is associated with transcriptional upregulation of NF-κB target genes such as IκBα and RelB. Taken together, our findings implicate that SM represent a novel double-hit strategy, sensitizing tumor and activating NK cells with one single drug.