Targeting CD70 in cutaneous T-cell lymphoma using an antibody-drug conjugate in patient-derived xenograft models

CD70-specific CAR NK cells expressing IL-15 for the treatment of CD19-negative B-cell malignancy

ABSTRACT

Chimeric antigen receptor (CAR) natural killer (NK) cells can eliminate tumors not only through the ability of the CAR molecule to recognize antigen-expressed cancer cells but also through NK-cell receptors themselves. This overcomes some of the limitations of CAR T cells, paving the way for CAR NK cells for safer and more effective off-the-shelf cellular therapy. In this study, CD70-specific (a pan-target of lymphoma) fourth-generation CAR with 4-1BB costimulatory domain and interleukin-15 (IL-15) was constructed and transduced into cord blood-derived NK cells by Baboon envelope pseudotyped lentiviral vector. CD70-CAR NK cells displayed superior cytotoxic activity in vitro and in vivo against CD19-negative B-cell lymphoma when compared with nontransduced NK cells and CD19-specific CAR NK cells. Importantly, mice that received 2 doses of CD70-CAR NK cells showed effective eradication of tumors, accompanied by increased concentration of plasma IL-15 and enhanced CAR NK cell proliferation and persistence. Our study suggests that repetitive administration-based CAR NK-cell therapy has clinical advantage compared with a single dose of CAR NK cells for the treatment of B-cell lymphoma.

Novel clinical risk stratification and treatment strategies in relapsed/refractory peripheral T-cell lymphoma

Peripheral T cell lymphoma (PTCL) represents a group of heterogeneous hematological malignancies, which are notoriously challenging to treat and outcomes are typically poor. Over the past two decades, clinical prognostic indices for patient risk stratification have evolved, while several targeted agents are now available to complement combination chemotherapy in the frontline setting or as a salvage strategy. With further understanding of the molecular pathobiology of PTCL, several innovative approaches incorporating immunomodulatory agents, epigenetic therapies, oncogenic kinase inhibitors and immunotherapeutics have come to the forefront. In this review, we provide a comprehensive overview of the progress in developing clinical prognostic indices for PTCL and describe the broad therapeutic landscape, emphasizing novel targetable pathways that have entered early phase clinical studies.

Single cells and TRUST4 reveal immunological features of the HFRS transcriptome

The etiology of hemorrhagic fever with renal syndrome (HFRS) is significantly impacted by a variety of immune cells. Nevertheless, the existing techniques for sequencing peripheral blood T cell receptor (TCR) or B cell receptor (BCR) libraries in HFRS are constrained by both limitations and high costs. In this investigation, we utilized the computational tool TRUST4 to generate TCR and BCR libraries utilizing comprehensive RNA-seq data from peripheral blood specimens of HFRS patients. This facilitated the examination of clonality and diversity within immune libraries linked to the condition. Despite previous research on immune cell function, the underlying mechanisms remain intricate, and differential gene expression across immune cell types and cell-to-cell interactions within immune cell clusters have not been thoroughly explored. To address this gap, we performed clustering analysis on 11 cell subsets derived from raw single-cell RNA-seq data, elucidating characteristic changes in cell subset proportions under disease conditions. Additionally, we utilized CellChat, a tool for cell-cell communication analysis, to investigate the impact of MIF family, CD70 family, and GALECTIN family cytokines-known to be involved in cell communication-on immune cell subsets. Furthermore, hdWGCNA analysis identified core genes implicated in HFRS pathogenesis within T cells and B cells. Trajectory analysis revealed that most cell subsets were in a developmental stage, with high expression of transcription factors such as NFKB and JUN in Effector CD8+ T cells, as well as in Naive CD4+ T cells and Naive B cells. Our findings provide a comprehensive understanding of the dynamic changes in immune cells during HFRS pathogenesis, identifying specific V genes and J genes in TCR and BCR that contribute to advancing our knowledge of HFRS. These insights offer potential implications for the diagnosis and treatment of this autoimmune disease.

"Next top" mouse models advancing CTCL research

This review systematically describes the application of in vivo mouse models in studying cutaneous T-cell lymphoma (CTCL), a complex hematological neoplasm. It highlights the diverse research approaches essential for understanding CTCL's intricate pathogenesis and evaluating potential treatments. The review categorizes various mouse models, including xenograft, syngeneic transplantation, and genetically engineered mouse models (GEMMs), emphasizing their contributions to understanding tumor-host interactions, gene functions, and studies on drug efficacy in CTCL. It acknowledges the limitations of these models, particularly in fully replicating human immune responses and early stages of CTCL. The review also highlights novel developments focusing on the potential of skin-targeted GEMMs in studying natural skin lymphoma progression and interactions with the immune system from onset. In conclusion, a balanced understanding of these models' strengths and weaknesses are essential for accelerating the deciphering of CTCL pathogenesis and developing treatment methods. The GEMMs engineered to target specifically skin-homing CD4+ T cells can be the next top mouse models that pave the way for exploring the effects of CTCL-related genes.

Immune cells in the B-cell lymphoma microenvironment: From basic research to clinical applications

ABSTRACT

B-cell lymphoma is a group of hematological malignancies characterized by variable genetic and biological features and clinical behaviors. The tumor microenvironment (TME) is a complex network in tumors, which consists of surrounding blood vessels, extracellular matrix, immune and non-immune cells, and signaling molecules. Increasing evidence has shown that the TME, especially immune cells within, is a double-edged sword, acting either as a tumor killer or as a promoter of tumor progression. These pro-tumor activities are driven by subpopulations of immune cells that express typical markers but have unique transcriptional characteristics, making tumor-associated immune cells good targets for human anti-cancer therapy by ablating immunosuppressive cells or enhancing immune-activated cells. Thus, exploring the role of immune cells in the TME provides distinct insights for immunotherapy in B-cell lymphoma. In this review, we elucidated the interaction between immune cells and tumor cells and their function in the initiation, progression, and prognosis of B-cell lymphoma, from preclinical experiments to clinical trials. Furthermore, we outlined potential therapeutic approaches and discussed the potential clinical value and future perspectives of targeting immune cells in patients with B-cell lymphoma.

CAR-T Cell Therapy for T-Cell Malignancies

Chimeric antigen receptor T-cell (CAR-T) therapy has revolutionized the treatment of B-cell lymphoid neoplasia and, in some instances, improved disease outcomes. Thus, six FDA-approved commercial CAR-T cell products that target antigens preferentially expressed on malignant B-cells or plasma cells have been introduced in the therapy of B-cell lymphomas, B-ALLs, and multiple myeloma. These therapeutic successes have triggered the application of CAR-T cell therapy to other hematologic tumors, including T-cell malignancies. However, the success of CAR-T cell therapies in T-cell neoplasms was considerably more limited due to the existence of some limiting factors, such as: 1) the sharing of mutual antigens between normal T-cells and CAR-T cells and malignant cells, determining fratricide events and severe T-cell aplasia; 2) the contamination of CAR-T cells used for CAR transduction with malignant T-cells. Allogeneic CAR-T products can avoid tumor contamination but raise other problems related to immunological incompatibility. In spite of these limitations, there has been significant progress in CD7- and CD5-targeted CAR-T cell therapy of T-cell malignancies in the last few years.

Increased expression of CD70 in relapsed acute myeloid leukemia after hypomethylating agents

Acute myeloid leukemia (AML) is the most common acute leukemia in adults. While induction chemotherapy leads to remission in most patients, a significant number will experience relapse. Therefore, there is a need for novel therapies that can improve remission rates in patients with relapsed and refractory AML. CD70 is the natural ligand for CD27 (a member of the TNF superfamily) and appears to be a promising therapeutic target. Consequently, there is considerable interest in developing chimeric antigen receptor (CAR) T-cell therapy products that can specifically target CD70 in various neoplasms, including AML. In this study, we employed routine diagnostic techniques, such as immunohistochemistry and flow cytometry, to investigate the expression of CD70 in bone marrow samples from treatment-naïve and relapsed AML patients after hypomethylating agents (HMA). Also, we evaluated the impact of HMA on CD70 expression and examined CD70 expression in various leukemic cell subsets and normal hematopoietic progenitors.

CD27/CD70 pathway activation in primary cutaneous CD4+ small/medium T-cell lymphoproliferative disorder

Primary cutaneous CD4+ small or medium T-cell lymphoproliferative disorder (PCSM-LPD) is a clonal T-cell proliferation disease confined to the skin. PCSM-LPD shares expression of T follicular helper (Tfh) cell markers with various mature T-cell lymphomas. However, the benign presentation of PCSM-LPD contrasts the clinical behavior of other Tfh-lymphomas. The aim of our study was to delineate the molecular similarities and differences between PCSM-LPD and other Tfh-derived lymphomas to explain the clinical behavior and unravel possible pathological mechanisms. We performed targeted next-generation sequencing of 19 genes recurrently mutated in T-cell neoplasms in n = 17 PCSM-LPD with high and in n = 21 PCSM-LPD with low tumor cell content. Furthermore, gene expression profiling was used to identify genes potentially expressed in the PD1-positive (PD1+) neoplastic cells. Expression of some of these genes was confirmed in situ using multistain immunofluorescence. We found that PCSM-LPD rarely harbored mutations recurrently detected in other T-cell neoplasms. PCSM-LPD is characterized by the invariable expression of the T-cell-receptor-associated LCK protein. CD70 and its ligand CD27 are co-expressed on PD1+ PCSM-LPD cells, suggestive of autoactivation of the CD70 pathway. In conclusion, PCSM-LPD differs from disseminated lymphomas of Tfh origin by their mutation profile. Activation of CD70 signaling also found in cutaneous T-cell lymphoma represents a potential driver of neoplastic proliferation of this benign neoplasia of Tfh. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Education and Empowering Special Forces to Eradicate Secret Defectors: Immune System-Based Treatment Approaches for Mature T- and NK-Cell Malignancies

Mature T- and NK-cell leukemia/lymphoma (MTCL/L) constitute a heterogeneous group of, currently, 30 distinct neoplastic entities that are overall rare, and all present with a challenging molecular markup. Thus, so far, the use of first-line cancer treatment modalities, including chemotherapies, achieve only limited clinical responses associated with discouraging prognoses. Recently, cancer immunotherapy has evolved rapidly, allowing us to help patients with, e.g., solid tumors and also relapsed/refractory B-cell malignancies to achieve durable clinical responses. In this review, we systematically unveiled the distinct immunotherapeutic approaches available, emphasizing the special impediments faced when trying to employ immune system defense mechanisms to target 'one of their own-gone mad'. We summarized the preclinical and clinical efforts made to employ the various platforms of cancer immunotherapies including antibody-drug conjugates, monoclonal as well as bispecific antibodies, immune-checkpoint blockades, and CAR T cell therapies. We emphasized the challenges to, but also the goals of, what needs to be done to achieve similar successes as seen for B-cell entities.

The functional and clinical roles of liquid biopsy in patient-derived models

The liquid biopsy includes the detection of circulating tumor cells (CTCs) and CTC clusters in blood, as well as the detection of, cell-free DNA (cfDNA)/circulating tumor DNA (ctDNA) and extracellular vesicles (EVs) in the patient's body fluid. Liquid biopsy has important roles in translational research. But its clinical utility is still under investigation. Newly emerged patient-derived xenograft (PDX) and CTC-derived xenograft (CDX) faithfully recapitulate the genetic and morphological features of the donor patients' tumor and patient-derived organoid (PDO) can mostly mimic tumor growth, tumor microenvironment and its response to drugs. In this review, we describe how the development of these patient-derived models has assisted the studies of CTCs and CTC clusters in terms of tumor biological behavior exploration, genomic analysis, and drug testing, with the help of the latest technology. We then summarize the studies of EVs and cfDNA/ctDNA in PDX and PDO models in early cancer diagnosis, tumor burden monitoring, drug test and response monitoring, and molecular profiling. The challenges faced and future perspectives of research related to liquid biopsy using patient-derived models are also discussed.