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Zusammenfassung. Die Transfusionsmedizin und die allogene Stammzelltransplantation gehören im Bereich der Hämatologie zu den bekannten und etablierten zellulären Therapien. Seit Jahrzehnten versucht man das patienteneigene Immunsystem so umzuprogrammieren, dass Tumorkrankheiten bekämpft werden. Ein Durchbruch ereignete sich durch die Herstellung und Optimierung von sog. chimeric antigen receptor (CAR) T-Zellen, gentechnologisch hergestellte, patienteneigene Lymphozyten, welche gezielt gegen ein Tumorantigen gerichtet sind. In diesem Übersichtsartikel diskutieren wir den Aufbau von CAR T-Zellen, deren Herstellung und den Ablauf einer CAR T-Zell Therapie in den Indikationen wie sie zurzeit zugelassen sind inklusive mögliche Komplikationen. Ausserdem geben wir einen Ausblick über die möglichen Zukunftsperspektiven zellulärer Therapien unter Berücksichtigung der aktuellen Herausforderungen.

Neutrophils have been thought to play a critical role in terminal differentiation of NK cells. Whether this effect is direct or a consequence of global immune changes with effects on NK-cell homeostasis remains unknown. In this study, we used high-resolution flow and mass cytometry to examine NK-cell repertoires in 64 patients with neutropenia and 27 healthy age- and sex-matched donors. A subgroup of patients with chronic neutropenia showed severely disrupted NK-cell homeostasis manifesting as increased frequencies of CD56bright NK cells and a lack of mature CD56dim NK cells. These immature NK-cell repertoires were characterized by expression of the proliferation/exhaustion markers Ki-67, Tim-3, and TIGIT and displayed blunted tumor target cell responses. Systems-level immune mapping revealed that the changes in immunophenotypes were confined to NK cells, leaving T-cell differentiation intact. RNA sequencing of NK cells from these patients showed upregulation of a network of genes, including TNFSF9, CENPF, MKI67, and TOP2A, associated with apoptosis and the cell cycle, but different from the conventional CD56bright signatures. Profiling of 249 plasma proteins showed a coordinated enrichment of pathways related to apoptosis and cell turnover, which correlated with immature NK-cell repertoires. Notably, most of these patients exhibited severe-grade neutropenia, suggesting that the profoundly altered NK-cell homeostasis was connected to the severity of their underlying etiology. Hence, although our data suggest that neutrophils are dispensable for NK-cell development and differentiation, some patients displayed a specific gap in the NK repertoire, associated with poor cytotoxic function and more severe disease manifestations.

Introduction In this study, we analyzed the changes of thrombin generation as marker of coagulation activation and von Willebrand factor (vWF) levels as a marker of endothelial activation in patients undergoing chemotherapy, autologous, or allogeneic HSCT. We studied possible associations to triggering factors, including acute GVHD, thrombosis, time to engraftment, and bleeding complications. Methods Seventy-six patients treated for hematologic malignancies at the University Hospital Basel between 2005 and 2008 took part in this study. Blood samples were collected before the start of chemotherapy or conditioning regime (median day -2), in an early phase (median day + 12), and at a later point in time (median day + 24). Results Thrombin generation decreased in all three groups to about 50% of the initial value. Patients undergoing autologous or allogeneic HSCT showed significantly (P = .026 and P = .01) higher vWF levels than patients undergoing chemotherapy. Eighteen patients (42%) receiving allogeneic HSCT developed GVHD, vWF levels in patients with GVHD were significantly (P = .008) higher than in patients without GVHD. Discussion Patients receiving autologous or allogeneic HSCT had significantly higher vWF levels in the acute phase after the transplant than patients receiving chemotherapy alone, implicating a persistent stimulation of the endothelium, possibly within the context of GVHD.

Current prognostic variables can only partly explain the large outcome heterogeneity in diffuse large B cell lymphoma (DLBCL). We aimed to investigate the utility of systems-level protein and immune repertoire profiling for outcome prognostication in DLBCL.In this retrospective study, we used proximity extension assay technology to quantify 81 immune-related proteins in serum or plasma in 2 independent cohorts in a total 111 DLBCL patients. Protein levels were assessed before and after treatment with rituximab and chemotherapy, and the patients were compared with 19 age- and sex-matched healthy blood donors. In a subset of the patients, we performed a broad mass cytometric characterization of immune cell repertoires in peripheral blood.Patients displayed large deviations in protein profiles compared with healthy controls. Development of a systemic protein deviation (SPD) score provided a 4-protein-based metric that reflected the overall degree of protein deviations compared with age- and sex-matched healthy blood donors. The SPD score identified patients with very poor overall survival in both cohorts and correlated with increased frequencies of peripheral blood PD-1Our results show that a simple metric based on measurement of a small set of serum or plasma proteins can be used to probe systemic immune changes associated with poor survival in DLBCL. This finding warrants further investigation in larger, prospective studies to establish a clinical prognostic biomarker.

Cellular therapies

Neutrophils are innate cells that have been suggested to play a critical role in terminal differentiation of NK cells. Whether this is a direct effect or a consequence of global immune changes with effects on NK cell homeostasis remains unknown. Here, we used high-resolution flow and mass cytometry to examine NK cell repertoires in 64 neutropenic patients and 27 healthy age- and gender-matched controls. A subgroup of neutropenic patients had lower frequencies and absolute numbers of NK cells, yet increased frequencies of CD56bright among NK cells (Figure 1A-C). Moreover, their CD56dim compartment was characterized by a block in differentiation, with a relative lack of NKG2A-CD57+KIR+ NK cells. In line with the differentiation arrest, no expansion of adaptive NK cells could be detected in CMV-seropositive patients from this subgroup. Furthermore, CD56dim NK cells showed increased frequencies of Ki-67+, Tim-3+ and TIGIT+ cells suggestive of activation and exhaustion (Figure 1D). The systemic imprint in the NK cell repertoire was associated with a blunted tumor target cell response with inefficient killing and a lower proportion of degranulating CD56dim cells (Figure 1E). RNA sequencing of the NK cell compartment further revealed that the differentiation arrest was linked to increased expression of transcription factors and genes involved in proliferation and cytokine signaling (Figure 1F). Serum protein profiling of 264 proteins showed upregulation of pathways related to apoptosis and cell turnover, as well as immune regulation and inflammation including higher levels of IL-10, IL-18 and IL-27 in these patients (Figure 1G-H). Notably, the majority of patients with perturbed NK cell compartment exhibited high-grade neutropenia, overall suggesting that the profoundly altered NK cell homeostasis was tightly connected to the severity of their underlying etiology (Figure 1I). Disclosures Meinke: XNK Therapeutics AB: Consultancy. Palmblad:Roche Sweden Inc: Speakers Bureau; Chieti Canada Inc: Consultancy, Membership on an entity's Board of Directors or advisory committees. Malmberg:Vycellix: Membership on an entity's Board of Directors or advisory committees; Fate Therapeutics: Consultancy, Patents & Royalties.

Global gene expression profiling of the tumor microenvironment in diffuse large B-cell lymphoma (DLBCL) has revealed broad innate immune signatures that distinguish the heterogeneous disease subtypes and correlate with good treatment outcome. However, we still lack tools to identify the relatively large group of patients that are refractory to initial therapy and have a dismal prognosis. Here, we used mass cytometry and serum profiling in a systems-level approach to analyze immune responses in 36 patients with aggressive B cell lymphoma and age- and sex-matched healthy controls. Stochastic neighbor embedding (t-SNE) analysis of protein profiles divided patients into two distinct clusters, with cluster 2 representing patients with a more severe deviation in their protein expression compared to healthy controls. Patients in cluster 2 showed a more dramatic perturbation of their immune cell repertoires with expansion of myeloid-derived suppressor cells (MDSCs), increased T cell differentiation and significantly higher expression of metabolic markers such as GLUT-1 and activation markers, including Ki67, CD38 and PD-1. An extended analysis of serum protein profiles in two independent cohorts (n=69 and n=80 patients, respectively) revealed that that the identified systemic immune signatures were linked to poor progression free survival (PFS) and inferior overall survival (OS). Immune monitoring during chemo-immunotherapy showed that most patients normalized their serum protein profiles. Notably, non-responding patients retained higher than normal expression of several proteins, including PD-L1, CD70, IL-18, granzyme A and CD83. These studies demonstrate distinct patterns of disease-driven alterations in the systemic immune response of DLBCL patients that are associated with poor survival and persist in patients who are refractory to therapy. Figure 1 System-level immune signatures associated with poor prognosis in DLBCL. A) Altered serum profiles in patients compared to healthy controls. Two clusters of patients were identified based on t-SNE analysis of serum profiles. B) Patients in cluster 2 had bulky disease and B symptoms. C) t-SNE map of all patients (n=36) and controls (n=17). Relative abundance of cells from healthy controls and patients in all areas of the t-SNE clustering, highlighting cell subsets that are larger or smaller in patients compared to healthy donors. Colors indicate the difference in kernel density estimation of the t-SNE data for patients and healthy controls. D) Abundance of monocytic myeloid-derived suppressor cells as percentage of all CD45+ cells in healthy donors and the two patient clusters. White, Healthy controls; Blue, Cluster 1; Red, Cluster 2. E) Major phenotypic differences between patient clusters shown as mean mass intensity (MMI) or percent positive cells for selected markers (CD38 and PD-1) across multiple subsets. White, Healthy controls; Blue, Cluster 1; Red, Cluster 2. F-G) Overall survival in patients with serologically defined immune signatures belonging to cluster 1 or 2. H) Abundance of serum proteins in patients that stayed in remission (n=24) compared to those that did not (n=6). Figure 1 Disclosures Olweus: Gilead Kite: Research Funding; Intellia: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Wahlin:Roche and Gilead: Consultancy. Fehniger:Cyto-Sen Therapeutics: Consultancy; Horizon Pharma PLC: Other: Consultancy (Spouse). Holte:Novartis: Honoraria, Other: Advisory board. Kolstad:Nordic Nanovector: Membership on an entity's Board of Directors or advisory committees, Research Funding; Merck: Research Funding. Malmberg:Fate Therapeutics, Inc.: Consultancy, Research Funding; Vycellix: Consultancy, Membership on an entity's Board of Directors or advisory committees.

Host control of infections crucially depends on the capability to kill pathogens with reactive oxygen species (ROS). However, these toxic molecules can also readily damage host components and cause severe immunopathology. Here, we show that neutrophils use their most abundant granule protein, myeloperoxidase, to target ROS specifically to pathogens while minimizing collateral tissue damage. A computational model predicted that myeloperoxidase efficiently scavenges diffusible H2O2 at the surface of phagosomal Salmonella and converts it into highly reactive HOCl (bleach), which rapidly damages biomolecules within a radius of less than 0.1 μm. Myeloperoxidase-deficient neutrophils were predicted to accumulate large quantities of H2O2 that still effectively kill Salmonella, but most H2O2 would leak from the phagosome. Salmonella stimulation of neutrophils from normal and myeloperoxidase-deficient human donors experimentally confirmed an inverse relationship between myeloperoxidase activity and extracellular H2O2 release. Myeloperoxidase-deficient mice infected with Salmonella had elevated hydrogen peroxide tissue levels and exacerbated oxidative damage of host lipids and DNA, despite almost normal Salmonella control. These data show that myeloperoxidase has a major function in mitigating collateral tissue damage during antimicrobial oxidative bursts, by converting diffusible long-lived H2O2 into highly reactive, microbicidal and locally confined HOCl at pathogen surfaces.

Supplemental digital content is available in the text., Background Occurring frequently after solid organ and hematopoietic stem cell transplantation, cytomegalovirus (CMV) replication remains a relevant cause of mortality and morbidity in affected patients. Despite these adverse effects, an increased alloreactivity of natural killer (NK) cells after CMV infection has been assumed, but the underlying physiopathological mechanisms have remained elusive. Methods We used serial analyses of NK cells before and after CMV infection in kidney transplant recipients as an in vivo model for CMV primary infection to explore the imprint of CMV infection using every patient as their own control: We analyzed NK cell phenotype and function in 47 CMV seronegative recipients of CMV seropositive kidney grafts, who developed CMV primary infection posttransplant. Seronegative recipients of seronegative kidney grafts served as controls. Results We observed a significant increase of NKG2C expressing NK cells after CMV infection (mean increase, 17.5%; 95% confidence interval [95% CI], 10.2-24.9, P < 0.001), whereas cluster of differentiation (CD)57 expressing cells decreased (mean decrease, 14.1%; 95% CI, 8.0-20.2; P < 0.001). Analysis of killer immunoglobulin-like receptor (KIR) expression showed an increase of cells expressing KIR2DL1 as their only inhibitory KIR in patients carrying the cognate ligand HLA-C2 (mean increase, 10.0%; 95% CI, 1.7-18.3; P = 0.018). In C2-negative individuals, KIR2DL1 expression decreased (mean decrease, 3.9%; 95% CI, 1.6-6.2; P = 0.001). As for activating KIR, there was no conclusive change pattern. Most importantly, we observed a significantly higher NK cell degranulation and IFNγ production in response to different target cells (target K562, CD107a: mean increase, 9.9%; 95% CI, 4.8-15.0; P < 0.001; IFNγ: mean increase, 6.6%; 95% CI, 1.6-11.1; P < 0.001; target MRC-5, CD107a: mean increase, 6.9%; 95% CI, 0.7-13.1; P = 0.03; IFNγ: mean increase, 4.8%; 95% CI, 1.7-7.8; P = 0.002). Conclusions We report evidence for an increased function of NK cells induced by CMV infection. This increased in vitro functionality was seen in NKG2C-positive and NKG2C-negative subsets, arguing for an NKG2C independent mechanism of action.

The multikinase inhibitor sorafenib has shown a strong anti-leukemic effect in FMS-like tyrosine kinase 3 (FLT3)-mutated acute myeloid leukemia (AML); however, remission is often transient. To better understand the role of sorafenib, we performed a retrospective analysis of all patients who received sorafenib in combination with allogeneic hematopoietic stem cell transplantation (HSCT) at our center. Seventeen patients with FLT3-ITD positive AML were treated with sorafenib in combination with allogeneic HSCT. Seven patients received sorafenib therapy pre- and posttransplant, and 10 patients were given sorafenib only posttransplant. Median duration of sorafenib treatment was 13 months (range 1-42); median dose was 600 mg (range 100-1200). Fourteen patients (82 %) achieved a complete remission (CR), while 5 patients (29 %) eventually developed progressive disease. Developing chronic graft-versus-host disease (GvHD) had a strong protective influence on the risk of sorafenib resistance (p = 0.028, HR 0.08, 95 % CI 0.01-0.76). In a total of 8 patients, sorafenib had to be stopped, paused or dose-reduced due to toxicity. In 5 patients with pronounced toxicity, we switched to an alternating dosing schedule with 1 month on/1 month off sorafenib. These patients subsequently remained in sustained complete molecular remission, with a median follow-up of 20 months. Our data indicate that sorafenib can achieve high rates of sustained remission in high-risk patients treated in combination with HSCT.

Flow cytometry is a powerful technology for high-throughput protein quantification at the single-cell level, widely used in basic research and routine clinical diagnostics. Traditionally, data analysis is carried out using manual gating, in which cut-offs are defined manually for each marker. Recent technical advances, including the introduction of mass cytometry, have increased the number of proteins that can be simultaneously assessed in each cell. To tackle the resulting escalation in data complexity, numerous new analysis algorithms have been developed. However, many of these show limitations in terms of providing statistical testing, data sharing, cross-experiment comparability integration with clinical data. We developed MetaGate as a platform for interactive statistical analysis and visualization of manually gated high-dimensional cytometry data with integration of clinical meta data. MetaGate allows manual gating to take place in traditional cytometry analysis software, while providing a combinatorial gating system for simple and transparent definition of biologically relevant cell populations. We demonstrate the utility of MetaGate through a comprehensive analysis of peripheral blood immune cells from 28 patients with diffuse large B-cell lymphoma (DLBCL) along with 17 age- and sex-matched healthy controls using two mass cytometry panels made of a total of 55 phenotypic markers. In a two-step process, raw data from 143 FCS files is first condensed through a data reduction algorithm and combined with information from manual gates, user-defined cellular populations and clinical meta data. This results in one single small project file containing all relevant information to allow rapid statistical calculation and visualization of any desired comparison, including box plots, heatmaps and volcano plots. Our detailed characterization of the peripheral blood immune cell repertoire in patients with DLBCL corroborate previous reports showing expansion of monocytic myeloid-derived suppressor cells, as well as an inverse correlation between NK cell numbers and disease progression., Competing Interests: Declaration of Interest K-J.M. is a consultant at Fate Therapeutics and Vycellix and has research support from Fate Therapeutics, Oncopeptides for studies unrelated to this work.