During the last decade the field of cancer immunotherapy has witnessed impressive progress. Highly effective immunotherapies such as immune checkpoint inhibition, and T-cell engaging therapies like bispecific T-cell engaging (BiTE) single-chain antibody constructs and chimeric antigen receptor (CAR) T cells have shown remarkable efficacy in clinical trials and some of these agents have already received regulatory approval. However, along with growing experience in the clinical application of these potent immunotherapeutic agents comes the increasing awareness of their inherent and potentially fatal adverse effects, most notably the cytokine release syndrome (CRS). This review provides a comprehensive overview of the mechanisms underlying CRS pathophysiology, risk factors, clinical presentation, differential diagnoses, and prognostic factors. In addition, based on the current evidence we give practical guidance to the management of the cytokine release syndrome.

Protein synthesis in all cells is carried out by macromolecular machines called ribosomes. Although the structures of prokaryotic, yeast and protist ribosomes have been determined, the more complex molecular architecture of metazoan 80S ribosomes has so far remained elusive. Here we present structures of Drosophila melanogaster and Homo sapiens 80S ribosomes in complex with the translation factor eEF2, E-site transfer RNA and Stm1-like proteins, based on high-resolution cryo-electron-microscopy density maps. These structures not only illustrate the co-evolution of metazoan-specific ribosomal RNA with ribosomal proteins but also reveal the presence of two additional structural layers in metazoan ribosomes, a well-ordered inner layer covered by a flexible RNA outer layer. The human and Drosophila ribosome structures will provide the basis for more detailed structural, biochemical and genetic experiments.

Key Points• We present comprehensive information on genetic driver events in a uniformly treated cohort of 664 adult AML patients aged 18 to 86 years.• Mutations in NPM1, FLT3, CEBPA, TP53, and, in patients ,60 years, DNMT3A and RUNX1, are the most important molecular risk factors in AML.The clinical and prognostic relevance of many recently identified driver gene mutations in adult acute myeloid leukemia (AML) is poorly defined. We sequenced the coding regions or hotspot areas of 68 recurrently mutated genes in a cohort of 664 patients aged 18 to 86 years treated on 2 phase 3 trials of the German AML Cooperative Group (AMLCG). The median number of 4 mutations per patient varied according to cytogenetic subgroup, age, and history of previous hematologic disorder or antineoplastic therapy. We found patterns of significantly comutated driver genes suggesting functional synergism. Conversely, we identified 8 virtually nonoverlapping patient subgroups, jointly comprising 78% of AML patients, that are defined by mutually exclusive genetic alterations. These subgroups, likely representing distinct underlying pathways of leukemogenesis, show widely divergent outcomes. Furthermore, we provide detailed information on associations between gene mutations, clinical patient characteristics, and therapeutic outcomes in this large cohort of uniformly treated AML patients. In multivariate analyses including a comprehensive set of molecular and clinical variables, we identified DNMT3A and RUNX1 mutations as important predictors of shorter overall survival (OS) in AML patients <60 years, and particularly in those with intermediate-risk cytogenetics. NPM1 mutations in the absence of FLT3-ITD, mutated TP53, and biallelic CEBPA mutations were identified as important molecular prognosticators of OS irrespective of patient age. In summary, our study provides a comprehensive overview of the spectrum, clinical associations, and prognostic relevance of recurrent driver gene mutations in a large cohort representing a broad spectrum and age range of intensively treated AML patients. (Blood. 2016;128(5):686-698)

Cells from the bone marrow can present peptides that are derived from tumors, transplants, and self-tissues. Here we describe how dendritic cells (DCs) process phagocytosed cell fragments onto major histocompatibility complex (MHC) class II products with unusual efficacy. This was monitored with the Y-Ae monoclonal antibody that is specific for complexes of I-Ab MHC class II presenting a peptide derived from I-Eα. When immature DCs from I-Ab mice were cultured for 5–20 h with activated I-E+ B blasts, either necrotic or apoptotic, the DCs produced the epitope recognized by the Y-Ae monoclonal antibody and stimulated T cells reactive with the same MHC–peptide complex. Antigen transfer was also observed with human cells, where human histocompatibility leukocyte antigen (HLA)-DRα includes the same peptide sequence as mouse I-Eα. Antigen transfer was preceded by uptake of B cell fragments into MHC class II–rich compartments. Quantitation of the amount of I-E protein in the B cell fragments revealed that phagocytosed I-E was 1–10 thousand times more efficient in generating MHC–peptide complexes than preprocessed I-E peptide. When we injected different I-E– bearing cells into C57BL/6 mice to look for a similar phenomenon in vivo, we found that short-lived migrating DCs could be processed by most of the recipient DCs in the lymph node. The consequence of antigen transfer from migratory DCs to lymph node DCs is not yet known, but we suggest that in the steady state, i.e., in the absence of stimuli for DC maturation, this transfer leads to peripheral tolerance of the T cell repertoire to self.

SummaryDetection of cytosolic DNA constitutes a central event in the context of numerous infectious and sterile inflammatory conditions. Recent studies have uncovered a bipartite mode of cytosolic DNA recognition, in which the cGAS-STING axis triggers antiviral immunity, whereas AIM2 triggers inflammasome activation. Here, we show that AIM2 is dispensable for DNA-mediated inflammasome activation in human myeloid cells. Instead, detection of cytosolic DNA by the cGAS-STING axis induces a cell death program initiating potassium efflux upstream of NLRP3. Forward genetics identified regulators of lysosomal trafficking to modulate this cell death

Immunotherapy has become an established pillar of cancer treatment improving the prognosis of many patients with a broad variety of hematological and solid malignancies. The two main drivers behind this success are checkpoint inhibitors (CPIs) and chimeric antigen receptor (CAR) T cells. This review summarizes seminal findings from clinical and translational studies recently presented or published at important meetings or in top-tier journals, respectively. For checkpoint blockade, current studies focus on combinational approaches, perioperative use, new tumor entities, response prediction, toxicity management and use in special patient populations. Regarding cellular immunotherapy, recent studies confirmed safety and efficacy of CAR T cells in larger cohorts of patients with acute lymphoblastic leukemia or diffuse large B cell lymphoma. Different strategies to translate the striking success of CAR T cells in B cell malignancies to other hematological and solid cancer types are currently under clinical investigation. Regarding the regional distribution of registered clinical immunotherapy trials a shift from PD-1 / PD-L1 trials (mainly performed in the US and Europe) to CAR T cell trials (majority of trials performed in the US and China) can be noted.

Measurable residual disease (MRD) is an important biomarker in acute myeloid leukemia (AML) that is used for prognostic, predictive, monitoring, and efficacy-response assessments. The European LeukemiaNet (ELN) MRD working party evaluates standardization and harmonization of MRD in an ongoing manner and has updated the 2018 ELN MRD recommendations based on significant developments in the field. New and revised recommendations were established during in-person and online meetings, and a two-stage Delphi poll was conducted to optimize consensus. All recommendations are graded by levels of evidence and agreement. Major changes include technical specifications for next generation sequencing (NGS)-based MRD testing and integrative assessments of MRD irrespective of technology. Other topics include use of MRD as a prognostic and surrogate endpoint for drug testing; selection of the technique, material, and appropriate time points for MRD assessment; and clinical implications of MRD assessment. In addition to technical recommendations for flow- and molecular- MRD analysis, we provide MRD thresholds and define MRD response, and detail how MRD results should be reported and combined if several techniques are used. MRD assessment in AML is complex and clinically relevant, and standardized approaches to application, interpretation, technical conduct, and reporting are of critical importance.

The Epstein-Barr virus (EBV)-encoded nuclear antigen EBNA1 is critical for the persistence of the viral episome in replicating EBV-transformed human B cells. Therefore, all EBV-induced tumors express this foreign antigen. However, EBNA1 is invisible to CD8+ cytotoxic T lymphocytes because its Gly/Ala repeat domain prevents proteasome-dependent processing for presentation on major histocompatibility complex (MHC) class I. We now describe that CD4+ T cells from healthy adults are primed to EBNA1. In fact, among latent EBV antigens that stimulate CD4+ T cells, EBNA1 is preferentially recognized. We present evidence that the CD4+ response may provide a protective role, including interferon γ secretion and direct cytolysis after encounter of transformed B lymphocyte cell lines (B-LCLs). Dendritic cells (DCs) process EBNA1 from purified protein and from MHC class II–mismatched, EBNA1-expressing cells including B-LCLs. In contrast, B-LCLs and Burkitt's lymphoma lines likely present EBNA1 after endogenous processing, as their capacity to cross-present from exogenous sources is weak or undetectable. By limiting dilution, there is a tight correlation between the capacity of CD4+ T cell lines to recognize autologous B-LCL–expressing EBNA1 and DCs that have captured EBNA1. Therefore, CD4+ T cells can respond to the EBNA1 protein that is crucial for EBV persistence. We suggest that this immune response is initiated in vivo by DCs that present EBV-infected B cells, and that EBNA1-specific CD4+ T cell immunity be enhanced to prevent and treat EBV-associated malignancies.