The costimulatory molecule CD70 is regulated by distinct molecular mechanisms and is associated with overall survival in diffuse large B-cell lymphoma

The Immunology of DLBCL

Diffuse large B-cell lymphoma (DLBCL) is an aggressive malignancy and is the most common type of malignant lymphoid neoplasm. While some DLBCLs exhibit strong cell-autonomous survival and proliferation activity, others depend on interactions with non-malignant cells for their survival and proliferation. Recent next-generation sequencing studies have linked these interactions with the molecular classification of DLBCL. For example, germinal center B-cell-like DLBCL tends to show strong associations with follicular T cells and epigenetic regulation of immune recognition molecules, whereas activated B-cell-like DLBCL shows frequent genetic aberrations affecting the class I major histocompatibility complex. Single-cell technologies have also provided detailed information about cell-cell interactions and the cell composition of the microenvironment of DLBCL. Aging-related immunological deterioration, i.e., immunosenescence, also plays an important role in DLBCL pathogenesis, especially in Epstein-Barr virus-positive DLBCL. Moreover, DLBCL in "immune-privileged sites"-where multiple immune-modulating mechanisms exist-shows unique biological features, including frequent down-regulation of immune recognition molecules and an immune-tolerogenic tumor microenvironment. These advances in understanding the immunology of DLBCL may contribute to the development of novel therapies targeting immune systems.

The dual role of CD70 in B-cell lymphomagenesis

BACKGROUND

CD70 is a costimulatory molecule that is transiently expressed on a small set of activated lymphocytes and is involved in T-cell-mediated immunity. However, the role of CD70 in B-cell malignancies remains controversial.

METHODS

We investigated the clinical relevance of CD70 genetic alterations and its protein expression in two diffuse large B-cell lymphoma (DLBCL) cohorts with different ethnic backgrounds. We also performed transcriptomic analysis to explore the role of CD70 alterations in tumour microenvironment. We further tested the blockade of CD70 in combination with PD-L1 inhibitor in a murine lymphoma model.

RESULTS

We showed that CD70 genetic aberrations occurred more frequently in the Chinese DLBCL cohort (56/233, 24.0%) than in the Swedish cohort (9/84, 10.8%), especially in those with concomitant hepatitis B virus (HBV) infection. The CD70 genetic changes in DLBCL resulted in a reduction/loss of protein expression and/or CD27 binding, which might impair T cell priming and were independently associated with poor overall survival. Paradoxically, we observed that over-expression of CD70 protein was also associated with a poor treatment response, as well as an advanced disease stage and EBV infection. More exhausted CD8+ T cells were furthermore identified in CD70 high-expression DLBCLs. Finally, in a murine lymphoma model, we demonstrated that blocking the CD70/CD27 and/or PD1/PD-L1 interactions could reduce CD70+ lymphoma growth in vivo, by directly impairing the tumour cell proliferation and rescuing the exhausted T cells.

CONCLUSIONS

Our findings suggest that CD70 can play a role in either tumour suppression or oncogenesis in DLBCL, likely via distinct immune evasion mechanisms, that is, impairing T cell priming or inducing T cell exhaustion. Characterisation of specific dysfunction of CD70 in DLBCL may thus provide opportunities for the development of novel targeted immuno-therapeutic strategies.

Vitreous proteomics, a gateway to improved understanding and stratification of diverse uveitis aetiologies

PURPOSE

The vitreous proteome might provide an attractive gateway to discriminate between various uveitis aetiologies and gain novel insights into the underlying pathophysiological processes. Here, we investigated 180 vitreous proteins to discover novel biomarkers and broaden disease insights by comparing (1). primary vitreoretinal lymphoma ((P)VRL) versus other aetiologies, (2). sarcoid uveitis versus tuberculosis (TB)-associated uveitis and (3). granulomatous (sarcoid and TB) uveitis versus other aetiologies.

METHODS

Vitreous protein levels were determined by proximity extension assay in 47 patients with intraocular inflammation and a prestudy diagnosis (cohort 1; training) and 22 patients with a blinded diagnosis (cohort 2; validation). Differentially expressed proteins identified by t-tests on cohort 1 were used to calculate Youden's indices. Pathway and network analysis was performed by ingenuity pathway analysis. A random forest classifier was trained to predict the diagnosis of blinded patients.

RESULTS

For (P)VRL stratification, the previously reported combined diagnostic value of IL-10 and IL-6 was confirmed. Additionally, CD70 was identified as potential novel marker for (P)VRL. However, the classifier trained on the entire cohort (cohort 1 and 2) relied primarily on the interleukin score for intraocular lymphoma diagnosis (ISOLD) or IL-10/IL-6 ratio and only showed a supportive role for CD70. Furthermore, sarcoid uveitis displayed increased levels of vitreous CCL17 as compared to TB-associated uveitis.

CONCLUSION

We underline the previously reported value of the ISOLD and the IL-10/IL-6 ratio for (P)VRL identification and present CD70 as a potentially valuable target for (P)VRL stratification. Finally, we also show that increased CCL17 levels might help to distinguish sarcoid uveitis from TB-associated uveitis.

Lysine Acetylation/Deacetylation Modification of Immune-Related Molecules in Cancer Immunotherapy

As major post-translational modifications (PTMs), acetylation and deacetylation are significant factors in signal transmission and cellular metabolism, and are modulated by a dynamic process via two pivotal categories of enzymes, histone acetyltransferases (HATs) and histone deacetylases (HDACs). In previous studies, dysregulation of lysine acetylation and deacetylation has been reported to be associated with the genesis and development of malignancy. Scientists have recently explored acetylation/deacetylation patterns and prospective cancer therapy techniques, and the FDA has approved four HDAC inhibitors (HDACi) to be used in clinical treatment. In the present review, the most recent developments in the area of lysine acetylation/deacetylation alteration in cancer immunotherapy were investigated. Firstly, a brief explanation of the acetylation/deacetylation process and relevant indispensable enzymes that participate therein is provided. Subsequently, a multitude of specific immune-related molecules involved in the lysine acetylation/deacetylation process are listed in the context of cancer, in addition to several therapeutic strategies associated with lysine acetylation/deacetylation modification in cancer immunotherapy. Finally, a number of prospective research fields related to cancer immunotherapy concepts are offered with detailed analysis. Overall, the present review may provide a reference for researchers in the relevant field of study, with the aim of being instructive and meaningful to further research as well as the selection of potential targets and effective measures for future cancer immunotherapy strategies.

Altered pathways and targeted therapy in double hit lymphoma

High-grade B-cell lymphoma with translocations involving MYC and BCL2 or BCL6, usually referred to as double hit lymphoma (DHL), is an aggressive hematological malignance with distinct genetic features and poor clinical prognosis. Current standard chemoimmunotherapy fails to confer satisfying outcomes and few targeted therapeutics are available for the treatment against DHL. Recently, the delineating of the genetic landscape in tumors has provided insight into both biology and targeted therapies. Therefore, it is essential to understand the altered signaling pathways of DHL to develop treatment strategies with better clinical benefits. Herein, we summarized the genetic alterations in the two DHL subtypes (DHL-BCL2 and DHL-BCL6). We further elucidate their implications on cellular processes, including anti-apoptosis, epigenetic regulations, B-cell receptor signaling, and immune escape. Ongoing and potential therapeutic strategies and targeted drugs steered by these alterations were reviewed accordingly. Based on these findings, we also discuss the therapeutic vulnerabilities that coincide with these genetic changes. We believe that the understanding of the DHL studies will provide insight into this disease and capacitate the finding of more effective treatment strategies.

The CD70-CD27 axis in oncology: the new kids on the block

The immune checkpoint molecule CD70 and its receptor CD27 are aberrantly expressed in many hematological and solid malignancies. Dysregulation of the CD70-CD27 axis within the tumor and its microenvironment is associated with tumor progression and immunosuppression. This is in contrast to physiological conditions, where tightly controlled expression of CD70 and CD27 plays a role in co-stimulation in immune responses. In hematological malignancies, cancer cells co-express CD70 and CD27 promoting stemness, proliferation and survival of malignancy. In solid tumors, only expression of CD70 is present on the tumor cells which can facilitate immune evasion through CD27 expression in the tumor microenvironment. The discovery of these tumor promoting and immunosuppressive effects of the CD70-CD27 axis has unfolded a novel target in the field of oncology, CD70.

In this review, we thoroughly discuss current insights into expression patterns and the role of the CD70-CD27 axis in hematological and solid malignancies, its effect on the tumor microenvironment and (pre)clinical therapeutic strategies.

Cusatuzumab for treatment of CD70-positive relapsed or refractory cutaneous T-cell lymphoma

BACKGROUND

The clinical benefit of cusatuzumab, a CD70-directed monoclonal antibody with enhanced effector functions, was investigated in patients with relapsed/refractory (R/R) cutaneous T-cell lymphoma (CTCL).

METHODS

In this cohort expansion of the ARGX-110-1201 study, 27 patients with R/R CTCL received cusatuzumab at 1 (n = 11) or 5 mg/kg (n = 16) once every 3 weeks to investigate its safety, dose, and exploratory efficacy. The pharmacokinetics, immunogenicity, CD70 expression, and CD70/CD27 biology were also assessed.

RESULTS

The most common adverse events included infusion-related reactions, pyrexia, and asthenia. Eighteen serious adverse events (grade 1-3) were reported in 11 patients; 1 of these (vasculitis) was considered drug-related. For 8 of the 11 patients receiving 1 mg/kg, anti-drug antibodies (ADAs) affected the minimal concentration, and this resulted in undetectable cusatuzumab concentrations at the end of treatment and, in some cases, a loss of response. This effect was greatly reduced in the patients receiving 5 mg/kg. The overall response rate was 23%; this included 1 complete response and 5 partial responses (PRs) in 26 of the 27 evaluable patients. In addition, 9 patients achieved stable disease. The mean duration on cusatuzumab was 5.2 months, and the median duration was 2.5 months. Patients with Sézary syndrome (SS) achieved a 60% PR rate with a dosage of 5 mg/kg and a 33% PR rate with a dosage of 1 mg/kg; this resulted in an overall response rate of 50% for patients with SS at both doses.

CONCLUSIONS

Cusatuzumab was well tolerated, and antitumor activity was observed at both 1 and 5 mg/kg in highly pretreated patients with R/R CTCL. The observed dose-dependent effect on exposure supports the use of 5 mg/kg for future development.

Prognostic and therapeutic value of somatic mutations in diffuse large B-cell lymphoma: A systematic review

Diffuse large B-cell lymphoma (DLBCL), the most common type of Non-Hodgkin lymphoma (NHL), is a highly heterogeneous and aggressive disease. Regardless of this heterogeneity, all patients receive the same first-line therapy, which fails in 30-40 % of patients, who are either refractory or relapse after remission. With the aim of stratifying patients to improve treatment outcome, different clinical and genetic biomarkers have been studied. The present systematic review aimed to identify somatic mutations that could serve as prognosis biomarkers or as therapeutic target mutations in DLBCL. Regarding their role as prognostic markers, mutations in CD58 and TP53 seem the most promising predictors of poor outcome although the combination of different alterations and other prognostic factors could be a more powerful strategy. On the other hand, different approaches regarding targeted therapy have been proposed. Therefore, mutational analysis could help guide treatment choice in DLBCL yet further studies and clinical trials are needed.

CD5+ diffuse large B-cell lymphoma: a narrative review

Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous entity, and cell surface cluster of differentiation (CD) 5 expression may represent a distinct subset. Here, we provide a narrative review of CD5+ DLBCL to understand its clinical implications. Between 5-10% of DLBCL express CD5, making it an uncommon subset. Studies have variably shown that CD5+ DLBCL may be associated with increased age, high lactate dehydrogenase, B symptoms, extra-nodal sites, higher International Prognostic Index score, and advanced stage. CD5+ DLBCLs are more likely to express Bcl-2, MYC, and MUM1; a large proportion exhibit an activated B-cell (ABC)-like phenotype. The balance of studies generally supports an independent prognostic value of CD5 in DLBCL While more aggressive first-line regimens have been advocated for CD5+ DLBCL, including dose-adjusted R-EPOCH and autologous stem cell transplant, evidence to support these approaches is lacking; further study is warranted to identify the optimal treatment strategy for this disease entity.

SOX11, CD70 and Treg cells configure the tumor immune microenvironment of aggressive mantle cell lymphoma

Mantle cell lymphoma (MCL) is a mature B-cell neoplasm with a heterogeneous clinical and biological behavior. SOX11 oncogenic expression contributes to the aggressiveness of these tumors by different mechanisms including tumor and stromal cell interactions. However, the precise composition of the immune cell microenvironment of MCL, its possible relationship to SOX11 expression, and how it may contribute to tumor behavior is not well known. Here, we performed an integrative transcriptome analysis of 730 immune-related genes combined with the immune cell phenotype analysis by immunohistochemistry in SOX11+ and SOX11- primary nodal MCL cases and non-neoplastic reactive lymph nodes (RLN). SOX11+ MCL had a significant lower T-cell intratumoral infiltration compared to negative cases. A reduced expression of MHCI/II-like and T-cell costimulation and signaling activation related transcripts was significantly associated with poor clinical outcome. Moreover, we identified CD70 as a SOX11 direct target gene, whose overexpression was induced in SOX11+ but not SOX11- tumor cells by CD40L in vitro. CD70 was overexpressed in primary SOX11+ MCL and it was associated with an immune unbalance of the tumor microenvironment characterized by increased number of effector Treg cell infiltration, higher proliferation, and aggressive clinical course. CD27 was expressed with moderate to strong intensity in 76% of cases. Overall, our results suggest that SOX11 expression in MCL is associated with an immunosuppressive microenvironment characterized by CD70 overexpression in tumor cells, increased Treg cell infiltration and downmodulation of antigen-processing and -presentation and T-cell activation that could promote MCL progression and represent a potential target for tailored therapies.

Antibody-drug conjugates for the treatment of lymphoma: clinical advances and latest progress

Antibody-drug conjugates (ADCs) are a promising class of immunotherapies with the potential to specifically target tumor cells and ameliorate the therapeutic index of cytotoxic drugs. ADCs comprise monoclonal antibodies, cytotoxic payloads with inherent antitumor activity, and specialized linkers connecting the two. In recent years, three ADCs, brentuximab vedotin, polatuzumab vedotin, and loncastuximab tesirine, have been approved and are already establishing their place in lymphoma treatment. As the efficacy and safety of ADCs have moved in synchrony with advances in their design, a plethora of novel ADCs have garnered growing interest as treatments. In this review, we provide an overview of the essential elements of ADC strategies in lymphoma and elucidate the up-to-date progress, current challenges, and novel targets of ADCs in this rapidly evolving field.

CD27 is required for protective lytic EBV antigen-specific CD8+ T-cell expansion

Primary immunodeficiencies in the costimulatory molecule CD27 and its ligand, CD70, predispose for pathologies of uncontrolled Epstein-Barr virus (EBV) infection in nearly all affected patients. We demonstrate that both depletion of CD27+ cells and antibody blocking of CD27 interaction with CD70 cause uncontrolled EBV infection in mice with reconstituted human immune system components. While overall CD8+ T-cell expansion and composition are unaltered after antibody blocking of CD27, only some EBV-specific CD8+ T-cell responses, exemplified by early lytic EBV antigen BMLF1-specific CD8+ T cells, are inhibited in their proliferation and killing of EBV-transformed B cells. This suggests that CD27 is not required for all CD8+ T-cell expansions and cytotoxicity but is required for a subset of CD8+ T-cell responses that protect us from EBV pathology.

A Review of Chimeric Antigen Receptor T-Cell Therapy for Myeloma and Lymphoma

Collectively, hematological malignancies account for the fourth most common malignancy. Myeloma and lymphoma are the most common types of hematological malignancies. Unfortunately, the management of refractory myeloma and lymphoma remains challenging. The discovery of new immunological therapies, namely chimeric antigen receptors T cells (CAR-T), outlined unprecedented B cell malignancies results. In this context, the CAR-T-based approach has led to the proliferation of many clinical studies. In this review, we will deal with the CAR-T structure, and we will summarize the primary clinical studies assessing the risks and benefits of CAR-T cell therapy. We will also deal with the adverse events and management of cytokine release syndromes/immune effector cell-associated neurotoxicity syndrome (ICANS). Subsequently, we will review potential future improvements to overcome refractoriness and improve expansion while decreasing CAR-T's off-target effects. The advances in the CAR-T platform represent a step forward with promising unlimited future possibilities that made it a paradigm-shifting for the management of B cell malignancies.

Specific Immune Response and Cytokine Production in CD70 Deficiency

Collective clinical and immunologic findings of defects in the CD27-CD70 axis indicate a primary immunodeficiency associated with terminal B-cell development defect and immune dysregulation leading to autoimmunity, uncontrolled viral infection, and lymphoma. Since the molecular mechanism underlying this entity of primary immunodeficiency has been recently described, more insight regarding the function and profile of immunity is required. Therefore, this study aimed to investigate stimulated antibody production, polyclonal vs. virus-specific T-cell response, and cytokine production of a CD70-deficient patient reported previously with early-onset antibody deficiency suffering from chronic viral infections and B-cell lymphoma. The patient and her family members were subjected to clinical evaluation, immunological assays, and functional analyses. The findings of this study indicate an impaired ability of B cells to produce immunoglobulins, and a poor effector function of T cells was also associated with the severity of clinical phenotype. Reduced proportions of cells expressing the memory marker CD45RO, as well as T-bet and Eomes, were observed in CD70-deficient T cells. The proportion of 2B4⁺ and PD-1⁺ virus-specific CD8⁺ T cells was also reduced in the patient. Although the CD70-mutated individuals presented with early-onset clinical manifestations that were well-controlled by using conventional immunological and anticancer chemotherapies, with better prognosis as compared with CD27-deficient patients, targeted treatment toward specific disturbed immune profile may improve the management and even prevent secondary complications.

Clinical Significance of Down-Regulated CD70 and CD27 Expression in Poor Prognosis of Esophageal Squamous Cell Carcinoma

Introduction

CD27 is a co-stimulatory immune checkpoint molecule in the tumor necrosis factor receptor superfamily. CD27 regulates the generation and maintenance of T cell immunity by binding to CD70 and regulating B-cell activation and immunoglobulin synthesis.

Materials and Methods

CD27 and CD70 expression were assessed in esophageal squamous cell carcinoma (ESCC) compared to normal tissue samples in the GSE53625 dataset of 179 paired cases and in 153 Chinese cases using reverse transcription quantitative polymerase chain reaction (RT-qPCR) and immunohistochemistry. The correlation was also investigated between CD27 and CD70 expression and immune-related pathways, including CD8⁺ T cell recruitment, function, and other inhibitory immune checkpoints.

Results

Levels of both CD27 and CD70 expression were down-regulated in ESCC compared to the paired normal tissues. CD27 and CD70 expression was mainly present in lymphocytes surrounding and infiltrating the tumor lesions but rarely expressed in tumor cells. Lost expression of CD27 and CD70 was associated with clinicopathological features, including depth of tumor invasion and better patient survival. Furthermore, CD27 expression was significantly associated with levels of CD8A, GZMB, IFNG, the CD8⁺ T cell recruitment-associated chemokines (CXCL9, CXCL10, and CXCL11), and CD8 receptors (CCR5, CXCR6, and CXCR3), while CD70 expression was inversely associated with levels of immunosuppressive checkpoints (PD-L1, PD-L2, and HHLA2).

Conclusion

Detection of CD70/CD27 expression could be further verified as a biomarker for ESCC early detection and prognosis prediction.

Lymphoma Predisposing Gene in an Extended Family: CD70 Signaling Defect

Genome-wide sequencing studies in pediatric cancer cohorts indicate that about 10% of patients have germline mutations within cancer predisposition genes. Within this group, primary immune deficiencies take the priority regarding the vulnerability of the patients to infectious agents and the difficulties of cancer management. On the other hand, early recognition of these diseases may offer specific targeted therapies and hematopoietic stem cell transplantation as an option. Besides therapeutic benefits, early diagnosis will provide genetic counseling for the family members. Within this context, an extended family with multiple consanguineous marriages and affected individuals, who presented with combined immune deficiency (CID) and/or Hodgkin lymphoma phenotype, were examined by exome sequencing. A pathogenic homozygous missense CD70 variation was detected (NM_001252.5:c332C>T) in concordance with CD70 phenotype and familial segregation was confirmed. CD70 variations in patients with CID and malignancy have very rarely been reported. This paper reports extended family with multiple affected members with CID and malignancy carrying a missense CD70 variation, and reviews the rare cases reported in the literature. Primary immune deficiencies appear to be a potential cause for pediatric cancers. Better focusing on these inborn disorders to prevent or make an early diagnosis of malignant transformation and reduce mortalities is important.

Targeting CD70 with cusatuzumab eliminates acute myeloid leukemia stem cells in patients treated with hypomethylating agents

Acute myeloid leukemia (AML) is driven by leukemia stem cells (LSCs) that resist conventional chemotherapy and are the major cause of relapse^1,2. Hypomethylating agents (HMAs) are the standard of care in the treatment of older or unfit patients with AML, but responses are modest and not durable^3-5. Here we demonstrate that LSCs upregulate the tumor necrosis factor family ligand CD70 in response to HMA treatment resulting in increased CD70/CD27 signaling. Blocking CD70/CD27 signaling and targeting CD70-expressing LSCs with cusatuzumab, a human αCD70 monoclonal antibody with enhanced antibody-dependent cellular cytotoxicity activity, eliminated LSCs in vitro and in xenotransplantation experiments. Based on these preclinical results, we performed a phase 1/2 trial in previously untreated older patients with AML with a single dose of cusatuzumab monotherapy followed by a combination therapy with the HMA azacitidine ( NCT03030612 ). We report results from the phase 1 dose escalation part of the clinical trial. Hematological responses in the 12 patients enrolled included 8 complete remission, 2 complete remission with incomplete blood count recovery and 2 partial remission with 4 patients achieving minimal residual disease negativity by flow cytometry at <10^-3. Median time to response was 3.3 months. Median progression-free survival was not reached yet at the time of the data cutoff. No dose-limiting toxicities were reported and the maximum tolerated dose of cusatuzumab was not reached. Importantly, cusatuzumab treatment substantially reduced LSCs and triggered gene signatures related to myeloid differentiation and apoptosis.

Signaling pathways involved in the T-cell-mediated immunity against Epstein-Barr virus: Lessons from genetic diseases

Primary immunodeficiencies (PIDs) provide researchers with unique models to understand in vivo immune responses in general and immunity to infections in particular. In humans, impaired immune control of Epstein-Barr virus (EBV) infection is associated with the occurrence of several different immunopathologic conditions; these include non-malignant and malignant B-cell lymphoproliferative disorders, hemophagocytic lymphohistiocytosis (HLH), a severe inflammatory condition, and a chronic acute EBV infection of T cells. Studies of PIDs associated with a predisposition to develop severe, chronic EBV infections have led to the identification of key components of immunity to EBV - notably the central role of T-cell expansion and its regulation in the pathophysiology of EBV-associated diseases. On one hand, the defective expansion of EBV-specific CD8 T cells results from mutations in genes involved in T-cell activation (such as RASGRP1, MAGT1, and ITK), DNA metabolism (CTPS1) or co-stimulatory pathways (CD70, CD27, and TNFSFR9 (also known as CD137/4-1BB)) leads to impaired elimination of proliferating EBV-infected B cells and the occurrence of lymphoma. On the other hand, protracted T-cell expansion and activation after the defective killing of EBV-infected B cells is caused by genetic defects in the components of the lytic granule exocytosis pathway or in the small adapter protein SH2D1A (also known as SAP), a key activator of T- and NK cell-cytotoxicity. In this setting, the persistence of EBV-infected cells results in HLH, a condition characterized by unleashed T-cell and macrophage activation. Moreover, genetic defects causing selective vulnerability to EBV infection have highlighted the role of co-receptor molecules (CD27, CD137, and SLAM-R) selectively involved in immune responses against infected B cells via specific T-B cell interactions.

CD19 and CD70 Dual-Target Chimeric Antigen Receptor T-Cell Therapy for the Treatment of Relapsed and Refractory Primary Central Nervous System Diffuse Large B-Cell Lymphoma

Background: The therapeutic efficacy of chimeric antigen receptor (CAR) T-cells targeting CD19 has been illustrated in the treatment of diffuse large B-cell lymphoma (DLBCL). However, there is a 21-35% relapse rate after anti-CD19 CAR T-cell induced remission. In addition, CAR T-cell therapy has severe adverse reactions, such as cytokine release syndrome (CRS) and CART-related encephalopathy syndrome (CRES). Because of the potential mortality associated with severe CRES, patients with primary central nervous system lymphoma (PCNSL) are usually excluded from clinical trials involving CAR T-cell therapy. Here, we report a case of refractory and relapsed primary central nervous system diffuse large B-cell lymphoma (PCNS-DLBCL). Case Presentation: The patient is a 67-year-old male who was diagnosed with PCNSL in 2011. He achieved complete remission (CR) after receiving 6 cycles of temozolomide and high-dose methotrexate. In December 2016, he experienced his first relapse and was treated with surgery and multicourse chemotherapy. He achieved CR again after the treatment. However, he experienced a second relapse in August 2017. MRI revealed a residual mass of 26 mm*35 mm*30 mm on the right side of the post-operative cavity and stale hemorrhage in the left basal ganglia. After confirming the expression of CD19 and CD70 in his tumor samples, the patient was given lymphodepletion chemotherapy followed by infusion of 4th generation CD19-CAR T-cells (4SCART19) and 4th generation CD70-CAR T-cells (4SCART70). One month later, the patient had symptomatic improvement, and brain MRI showed CR. Both CART19 and CART70 cells were detected in the 10th month after CAR T-cell infusion. Notably, neither CRS nor CRES occurred during treatment and follow-up. To date, the patient has maintained disease-free survival with more than 17 months of follow-up. Conclusions: The results of this study indicate that combination of CD19- and CD70-specific CAR T-cells may effectively target PCNSL and maintain disease-free survival without inducing CRS or CRES. Therefore, central nervous system lymphoma is not an absolute contraindication for dual-target CAR T-cell therapy.

CD70 expression correlates with a worse prognosis in malignant pleural mesothelioma patients via immune evasion and enhanced invasiveness

Diffuse malignant mesothelioma of the pleura (MPM) is a highly aggressive tumour that typically is associated with short survival. CD70 and CD27 belong to the tumour necrosis factor (TNF) and the TNF receptor (TNFR) superfamily, respectively. Under physiological conditions, the tightly regulated interaction between CD70 and CD27 plays a co-stimulatory role in promoting T-cell expansion and differentiation through the NFκB pathway. Aberrantly high CD70 expression has been documented in haematological and solid malignancies in association with immune evasion in malignant cells. In this study, 172 well-characterised primary diffuse MPM tumours including epithelioid (n = 145), biphasic (n = 15), and sarcomatoid (n = 12) histotypes were evaluated immunohistochemically for CD70, CD27, CD3, CD4, CD8, CD56, PDCD1 (PD-1), and FOXP3 expression. Twenty per cent (34/172) of the mesothelioma cells expressed CD70 on the cell membrane. Overall survival was significantly decreased in the cohort of patients with CD70-expressing tumour cells (p < 0.01). Patients with MPM containing a higher number of CD3⁺ (p < 0.01), CD4⁺ (p < 0.01), CD8⁺ (p < 0.01), or FOXP3⁺ (p < 0.01) tumour-infiltrating lymphoid cells (TILs) showed significantly worse clinical outcomes. As potential independent risk factors for MPM patients, multivariate Cox proportional hazards regression analysis revealed CD70 expression on mesothelioma cells [hazard ratio (HR) 2.25; p = 0.010], higher FOXP3⁺ TILs (HR 2.81; p = 0.004), and higher CD3⁺ TIL accumulation (HR 6.12; p < 0.001). In contrast, as a potential independent favourable factor, higher CD27⁺ TIL accumulation (HR 0.48; p = 0.037) was identified. In vitro experiments and an immunodeficient mouse model revealed that CD70 enhances the invasiveness of MPM cells through MET-ERK axis activation. Further analyses in syngeneic mouse models demonstrated possible roles for CD70 in immune evasion. Collectively, these findings suggest that the CD70-CD27 pathway enhances the malignant phenotypes of MPM and diminishes anti-tumor immune response in patients with these neoplasms. These markers might be useful in MPM for prognostic evaluations as well as targeted therapeutics. © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Screening a Broad Range of Solid and Haematological Tumour Types for CD70 Expression Using a Uniform IHC Methodology as Potential Patient Stratification Method

The constitutive expression of CD70 has been described in various haematological and solid tumour types. In addition, the co-expression of its receptor in tumours has been demonstrated, mediating tumour cell proliferation. Although CD70 expression is a prerequisite to enrol patients in solid tumour clinical trials using anti-CD70 immunotherapy, there is currently no standardised test to evaluate CD70 expression. These differences in immunohistochemistry (IHC) protocols make it challenging to compare the expression levels that were obtained in different studies, pointing out the need for one uniform methodology. In this retrospective study, over 600 tumour samples from different solid and haematological malignancies were analysed while using one validated IHC method. CD70 and CD27 expression was demonstrated in a broad range of tumour types. In solid tumours, 43% demonstrated CD70 positivity with the highest degree in renal cell carcinoma (79.5%). Kaposi sarcoma showed no CD70 expression on the tumour cells. In lymphoma samples, 58% demonstrated CD70 positivity. Moreover, the co-expression of CD70 and CD27 was observed in 39% of lymphoma samples. These findings highlight the need to further explore anti-CD70 therapies in a broad range of CD70 expressing tumour types and in doing so, implementing one standardised protocol to define CD70 overexpression to use it as a diagnostic tool.

Expression of CD70 (CD27L) Is Associated With Epithelioid and Sarcomatous Features in IDH-Wild-Type Glioblastoma

Glioblastoma is an aggressive, often recalcitrant disease. In the majority of cases, prognosis is dismal and current therapies only moderately prolong survival. Immunotherapy is increasingly being recognized as an effective treatment modality. CD70 is a transmembrane protein that shows restricted expression in tissue but has been described in various malignancies. Therapeutic targeting of CD70 has demonstrated antitumor efficacy and is in clinical trials. Here, we sought to characterize CD70 expression in a large cohort of gliomas (n = 205) using tissue microarrays. We identified a subset of tumors (n = 18, 8.8% of high-grade gliomas) exhibiting moderate-to-strong immunoreactivity that enriched for the IDH-wild-type glioblastoma variants gliosarcoma (n = 10) and the newly described epithelioid glioblastoma (n = 4). CD70 expression was associated with prolonged survival in gliosarcoma. Analysis of TCGA datasets showed significantly increased CD70 expression in mesenchymal tumors and prolonged survival in recurrent non-G-CIMP high-expressing tumors. In CD70+ gliomas, there was a significant increase in CD68/CD163/HLA-DR+ tumor-associated macrophages, but not CD27+ TIL. These results confirm prior in vitro studies and demonstrate expression in a clinical cohort. The absence of CD70 expression in the post-treatment setting may portend more clinically aggressive disease in gliosarcoma. However, larger-scale studies will be needed to characterize and validate this relationship.

Tumor associated CD70 expression is involved in promoting tumor migration and macrophage infiltration in GBM

Tumor migration/metastasis and immunosuppression are major obstacles in effective cancer therapy. Incidentally, these 2 hurdles usually coexist inside tumors, therefore making therapy significantly more complicated, as both oncogenic mechanisms must be addressed for successful therapeutic intervention. Our recent report highlights that the tumor expression of a TNF family member, CD70, is correlated with poor survival for primary gliomas. In this study, we investigated how CD70 expression by GBM affects the characteristics of tumor cells and the tumor microenvironment. We found that the ablation of CD70 in primary GBM decreased CD44 and SOX2 gene expression, and inhibited tumor migration, growth and the ability to attract monocyte-derived M2 macrophages in vitro. In the tumor microenvironment, CD70 was associated with immune cell infiltrates, such as T cells; myeloid-derived suppressor cells; and monocytes/macrophages based on the RNA-sequencing profile. The CD163+ macrophages were far more abundant than T cells were. This overwhelming level of macrophages was identified only in GBM and not in low-grade gliomas and normal brain specimens, implying their tumor association. CD70 was detected only on tumor cells, not on macrophages, and was highly correlated with CD163 gene expression in primary GBM. Additionally, the co-expression of the CD70 and CD163 genes was found to correlate with decreased survival for patients with primary GBM. Together, these data suggest that CD70 expression is involved in promoting tumor aggressiveness and immunosuppression via tumor-associated macrophage recruitment/activation. Our current efforts to target this molecule using chimeric antigen receptor T cells hold great potential for treating patients with GBM.

Inherited CD70 deficiency in humans reveals a critical role for the CD70-CD27 pathway in immunity to Epstein-Barr virus infection

Izawa et al. identify the first patient with CD70 deficiency suffering from recurrent EBV-induced B cell proliferations including Hodgkin’s lymphoma. Expression of CD70 on B cells is necessary to induce proliferation of EBV-specific T cells.

Epstein-Barr virus (EBV) infection in humans is a major trigger of malignant and nonmalignant B cell proliferations. CD27 is a co-stimulatory molecule of T cells, and inherited CD27 deficiency is characterized by high susceptibility to EBV infection, though the underlying pathological mechanisms have not yet been identified. In this study, we report a patient suffering from recurrent EBV-induced B cell proliferations including Hodgkin’s lymphoma because of a deficiency in CD70, the ligand of CD27. We show that EBV-specific T lymphocytes did not expand properly when stimulated with CD70-deficient EBV-infected B cells, whereas expression of CD70 in B cells restored expansion, indicating that CD70 on B cells but not on T cells is required for efficient proliferation of T cells. CD70 was found to be up-regulated on B cells when activated and during EBV infection. The proliferation of T cells triggered by CD70-expressing B cells was dependent on CD27 and CD3 on T cells. Importantly, CD27-deficient T cells failed to proliferate when stimulated with CD70-expressing B cells. Thus, the CD70–CD27 pathway appears to be a crucial component of EBV-specific T cell immunity and more generally for the immune surveillance of B cells and may be a target for immunotherapy of B cell malignancies.

Cross-platform assessment of genomic imbalance confirms the clinical relevance of genomic complexity and reveals loci with potential pathogenic roles in diffuse large B-cell lymphoma

Genomic copy number alterations (CNAs) in diffuse large B-cell lymphoma (DLBCL) have roles in disease pathogenesis, but overall clinical relevance remains unclear. Herein, an unbiased algorithm was uniformly applied across three genome profiling datasets comprising 392 newly-diagnosed DLBCL specimens that defined 32 overlapping CNAs, involving 36 minimal common regions (MCRs). Scoring criteria were established for 50 aberrations within the MCRs while considering peak gains/losses. Application of these criteria to independent datasets revealed novel candidate genes with coordinated expression, such as CNOT2, potentially with pathogenic roles. No one single aberration significantly associated with patient outcome across datasets, but genomic complexity, defined by imbalance in more than one MCR, significantly portended adverse outcome in two of three independent datasets. Thus, the standardized scoring of CNAs currently developed can be uniformly applied across platforms, affording robust validation of genomic imbalance and complexity in DLBCL and overall clinical utility as biomarkers of patient outcome.

CD70: A Potential Target in Breast Cancer?

CD70 is a co-stimulatory molecule involved in the immune response and also in cancer development and progression. Recent studies show that high CD70 expression in cancer cells may inhibit the anti-tumor response. Furthermore, CD70 expression has been reported as a predictive marker of resistance to chemotherapy in ovarian cancers. Some in vitro studies have shown that CD70 expression is epigenetically down-regulated through hypermethylation of its promoter during tumoral progression. This study evaluated the level of CD70 expression in surgical samples of breast invasive tumors and determined its correlation with CD70 promoter methylation.

Twenty “luminal A” and 20 “basal-like” frozen samples from early breast tumors were retrospectively selected. CD70 expression was evaluated by quantitative real-time PCR. Total DNA was bisulfite-treated, and methylation levels of 5 consecutive CG sites present in the proximal region (-464, -421) of the promoter were assessed by pyrosequencing analysis. Statistical analyses were performed using the Mann-Whitney test.

The median relative CD70 expression level was 0.37 and was significantly higher in the basal-like group (0.78 [0.24-31.7]) compared to the luminal A group (0.25 [0.03-1.83], p=0.0001). The median methylation level was 61%, with no significant difference between the basal-like (63%) and luminal A (58%) groups. No correlation was found between CD70 expression and CD70 methylation level.

In this study, higher CD70 expression was observed in the basal-like group, but this expression was not related to promoter methylation. The higher expression in the poor-prognosis subgroup of patients makes CD70 a potential target for emerging anti-CD70 therapies.

Exome sequencing reveals novel mutation targets in diffuse large B-cell lymphomas derived from Chinese patients

Next-generation sequencing studies on diffuse large B-cell lymphomas (DLBCLs) have revealed novel targets of genetic aberrations but also high intercohort heterogeneity. Previous studies have suggested that the prevalence of disease subgroups and cytogenetic profiles differ between Western and Asian patients. To characterize the coding genome of Chinese DLBCL, we performed whole-exome sequencing of DNA derived from 31 tumors and respective peripheral blood samples. The mutation prevalence of B2M, CD70, DTX1, LYN, TMSB4X, and UBE2A was investigated in an additional 105 tumor samples. We discovered 11 novel targets of recurrent mutations in DLBCL that included functionally relevant genes such as LYN and TMSB4X. Additional genes were found mutated at high frequency (≥10%) in the Chinese cohort including DTX1, which was the most prevalent mutation target in the Notch pathway. We furthermore demonstrated that mutations in DTX1 impair its function as a negative regulator of Notch. Novel and previous unappreciated targets of somatic mutations in DLBCL identified in this study support the existence of additional/alternative tumorigenic pathways in these tumors. The observed differences with previous reports might be explained by the genetic heterogeneity of DLBCL, the germline genetic makeup of Chinese individuals, and/or exposure to distinct etiological agents.

TGF-β upregulates CD70 expression and induces exhaustion of effector memory T cells in B-cell non-Hodgkin's lymphoma

Transforming growth factor beta (TGF-β) has an important role in mediating T-cell suppression in B-cell non-Hodgkin lymphoma (NHL). However, the underlying mechanism responsible for TGF-β-mediated inhibition of effector memory T (Tm) cells is largely unknown. As reported here, we show that exhaustion is a major mechanism by which TGF-β inhibits Tm cells, and TGF-β mediated exhaustion is associated with upregulation of CD70. We found that TGF-β upregulates CD70 expression on effector Tm cells while it preferentially induces Foxp3 expression in naive T cells. CD70 induction by TGF-β is Smad3-dependent and involves IL-2/Stat5 signaling. CD70+ T cells account for TGF-β-induced exhaustion of effector Tm cells. Both TGF-β-induced and preexisting intratumoral CD70+ effector Tm cells from B-cell NHL have an exhausted phenotype and express higher levels of PD-1 and TIM-3 compared with CD70- T cells. Signaling transduction, proliferation and cytokine production are profoundly decreased in these cells, and they are highly susceptible to apoptosis. Clinically, intratumoral CD70-expressing T cells are prevalent in follicular B-cell lymphoma (FL) biopsy specimens, and increased numbers of intratumoral CD70+ T cells correlate with an inferior patient outcome. These findings confirm TGF-β-mediated effector Tm cell exhaustion as an important mechanism of immune suppression in B-cell NHL.

Genome-wide copy-number analyses reveal genomic abnormalities involved in transformation of follicular lymphoma

Follicular lymphoma (FL), the second most common type of non-Hodgkin lymphoma in the western world, is characterized by the t(14;18) translocation, which is present in up to 90% of cases. We studied 277 lymphoma samples (198 FL and 79 transformed FL [tFL]) using a single-nucleotide polymorphism array to identify the secondary chromosomal abnormalities that drive the development of FL and its transformation to diffuse large B-cell lymphoma. Common recurrent chromosomal abnormalities in FL included gains of 2, 5, 7, 6p, 8, 12, 17q, 18, 21, and X and losses on 6q and 17p. We also observed many frequent small abnormalities, including losses of 1p36.33-p36.31, 6q23.3-q24.1, and 10q23.1-q25.1 and gains of 2p16.1-p15, 8q24.13-q24.3, and 12q12-q13.13, and identified candidate genes that may be driving this selection. Recurrent abnormalities more frequent in tFL samples included gains of 3q27.3-q28 and chromosome 11 and losses of 9p21.3 and 15q. Four abnormalities, gain of X or Xp and losses of 6q23.2-24.1 or 6q13-15, predicted overall survival. Abnormalities associated with transformation of the disease likely impair immune surveillance, activate the nuclear factor-κB pathway, and deregulate p53 and B-cell transcription factors.