Pretreatment with IL-15 and IL-18 rescues natural killer cells from granzyme B-mediated apoptosis after cryopreservation

Human natural killer (NK) cell-based therapies are under assessment for treating various cancers, but cryopreservation reduces both the recovery and function of NK cells, thereby limiting their therapeutic feasibility. Using cryopreservation protocols optimized for T cells, here we find that ~75% of NK cells die within 24 h post-thaw, with the remaining cells displaying reduced cytotoxicity. Using CRISPR-Cas9 gene editing and confocal microscopy, we find that cryopreserved NK cells largely die via apoptosis initiated by leakage of granzyme B from cytotoxic vesicles. Pretreatment of NK cells with a combination of Interleukins-15 (IL-15) and IL-18 prior to cryopreservation improves NK cell recovery to ~90-100% and enables equal tumour control in a xenograft model of disseminated Raji cell lymphoma compared to non-cryopreserved NK cells. The mechanism of IL-15 and IL-18-induced protection incorporates two mechanisms: a transient reduction in intracellular granzyme B levels via degranulation, and the induction of antiapoptotic genes.

Epitope base editing CD45 in hematopoietic cells enables universal blood cancer immune therapy

In the absence of cell surface cancer-specific antigens, immunotherapies such as chimeric antigen receptor (CAR) T cells, monoclonal antibodies, or bispecific T cell engagers typically target lineage antigens. Currently, such immunotherapies are individually designed and tested for each disease. This approach is inefficient and limited to a few lineage antigens for which the on-target/off-tumor toxicities are clinically tolerated. Here, we sought to develop a universal CAR T cell therapy for blood cancers directed against the pan-leukocyte marker CD45. To protect healthy hematopoietic cells, including CAR T cells, from CD45-directed on-target/off-tumor toxicity while preserving the essential functions of CD45, we mapped the epitope on CD45 that is targeted by the CAR and used CRISPR adenine base editing to install a function-preserving mutation sufficient to evade CAR T cell recognition. Epitope-edited CD45 CAR T cells were fratricide resistant and effective against patient-derived acute myeloid leukemia, B cell lymphoma, and acute T cell leukemia. Epitope-edited hematopoietic stem cells (HSCs) were protected from CAR T cells and, unlike CD45 knockout cells, could engraft, persist, and differentiate in vivo. Ex vivo epitope editing in HSCs and T cells enables the safe and effective use of CD45-directed CAR T cells and bispecific T cell engagers for the universal treatment of hematologic malignancies and might be exploited for other diseases requiring intensive hematopoietic ablation.

Next-Generation CAR T-cell Therapies

SUMMARY

CD19- and B-cell maturation antigen (BCMA)-directed chimeric antigen receptor (CAR) T cells have enabled unprecedented responses in a subset of refractory patients with B-cell and plasma cell malignancies, leading to their approval by the FDA for the treatment of leukemia, lymphoma, and myeloma. These "living drugs" can become part of a synthetic immune system, persisting at least a decade in some patients. However, despite this tremendous impact, significant unmet treatment needs remain for patients with hematologic malignancies and solid cancers. In this perspective, we highlight recent innovations that advance the field toward production of a more potent and universal cellular immunotherapy of the future. Next-generation CAR T cells will incorporate advances in gene engineering and synthetic biology to enhance functionality and persistence, and reduce treatment-associated toxicities. The combination of autologous CAR T cells with various allogeneic cell treatment strategies designed to target the immunosuppressive tumor microenvironment will broaden the impact of future CAR T-cell therapies.

Newly diagnosed isolated myeloid sarcoma-paired NGS panel analysis of extramedullary tumor and bone marrow

Isolated myeloid sarcoma (MS) is a rare malignancy in which myeloid blast forms tumors at various locations while the bone marrow (BM) remains cytomorphologically free from disease. We analyzed isolated MS from four patients and their BMs at initial diagnosis and follow-up, using a custom next-generation sequencing (NGS) panel. We observed possible clonal evolution and a clonal hematopoiesis of indeterminate potential (CHIP)-like finding in the BM of one of three cases with detectable mutations. Clinical presentation of one patient suggested extramedullary confined homing of blasts to distal sites in the relapse situation still sparing the BM. In summary, our findings shall motivate future work regarding signals of extramedullary blast trafficking and clonal evolution in MS.

Fatal Myelotoxicity Following Palliative Chemotherapy With Cisplatin and Gemcitabine in a Patient With Stage IV Cholangiocarcinoma Linked to Post Mortem Diagnosis of Fanconi Anemia

Unrecognized genome instability syndromes can potentially impede the rational treatment of cancer in rare patients. Identification of cancer patients with a hereditary condition is a compelling necessity for oncologists, giving varying hypersensitivities to various chemotherapeutic agents or radiation, depending on the underlying genetic cause. Omission of genetic testing in the setting of an overlooked hereditary syndrome may lead to unexpected and unbearable toxicity from oncological standard approaches. We present a case of a 33-year-old man with an early-onset stage IV intrahepatic cholangiocarcinoma, who experienced unusual bone marrow failure and neutropenic fever syndrome as a consequence of palliative chemotherapy containing cisplatin and gemcitabine, leading to a fatal outcome on day 25 of his first chemotherapeutic cycle. The constellation of bone marrow failure after exposure to the platinum-based agent cisplatin, the presence of an early-onset solid malignancy and the critical appraisal of further phenotypical features raised suspicion of a hereditary genome instability syndrome. Whole-exome sequencing from buccal swab DNA enabled the post mortem diagnosis of Fanconi anemia, most likely linked to the fatal outcome due to utilization of the DNA crosslinking agent cisplatin. The patient's phenotype was exceptional, as he never displayed significant hematologic abnormalities, which is the hallmark of Fanconi anemia. As such, this case stresses the importance to at least question the possibility of a hereditary basis in cases of relatively early-onset malignancy before defining an oncological treatment strategy.

Correction to: DNA methylation-based reclassification of olfactory neuroblastoma

In the original publication, the second name of the twentieth author was incorrect. It should read as 'Miguel Sáinz-Jaspeado'. The original publication of the article has been updated to reflect the change. This correction was authored by Ulrich Schüller on behalf of all authors of the original publication.

DNA methylation-based classification of central nervous system tumours

Accurate pathological diagnosis is crucial for optimal management of patients with cancer. For the approximately 100 known tumour types of the central nervous system, standardization of the diagnostic process has been shown to be particularly challenging-with substantial inter-observer variability in the histopathological diagnosis of many tumour types. Here we present a comprehensive approach for the DNA methylation-based classification of central nervous system tumours across all entities and age groups, and demonstrate its application in a routine diagnostic setting. We show that the availability of this method may have a substantial impact on diagnostic precision compared to standard methods, resulting in a change of diagnosis in up to 12% of prospective cases. For broader accessibility, we have designed a free online classifier tool, the use of which does not require any additional onsite data processing. Our results provide a blueprint for the generation of machine-learning-based tumour classifiers across other cancer entities, with the potential to fundamentally transform tumour pathology.