Epitope topography of agonist antibodies to the checkpoint inhibitory receptor BTLA

B and T lymphocyte attenuator (BTLA) is an attractive target for a new class of therapeutics that attempt to rebalance the immune system by agonizing checkpoint inhibitory receptors (CIRs). Herpesvirus entry mediator (HVEM) binds BTLA in both trans- and cis-orientations. We report here the development and structural characterization of three humanized BTLA agonist antibodies, 22B3, 25F7, and 23C8. We determined the crystal structures of the antibody-BTLA complexes, showing that these antibodies bind distinct and non-overlapping epitopes of BTLA. While all three antibodies activate BTLA, 22B3 mimics HVEM binding to BTLA and shows the strongest agonistic activity in functional cell assays and in an imiquimod-induced mouse model of psoriasis. 22B3 is also capable of modulating HVEM signaling through the BTLA-HVEM cis-interaction. The data obtained from crystal structures, biochemical assays, and functional studies provide a mechanistic model of HVEM and BTLA organization on the cell surface and informed the discovery of a highly active BTLA agonist.

Interaction between DNMT3B and MYH11 via hypermethylation regulates gastric cancer progression

BACKGROUND

Gastric cancer (GC) has an unwelcoming prognosis when diagnosed at an advanced stage. The purpose of this study was to examine the expression of myosin heavy chain 11 (MYH11) in GC and mechanisms related.

METHODS

The MYH11 expression in GC was investigated via the SangerBox platform. MYH11 expression in GC tissues and cell lines was examined by immunohistochemistry, RT-qPCR, and western blot. The relationship between MYH11 expression and patients' prognosis was analyzed. The effects of MYH11 on the biological behaviors of GC cells were investigated by gain-of-function experiments. Bioinformatics analysis was used to find genes with relevance to MYH11 expression in GC. The relationship was verified by luciferase and ChIP-qPCR assays, followed by rescue assay validation. The causes of MYH11 downregulation in GC were verified by quantitative methylation-specific PCR. Finally, the effect of MYH11 on tumor growth was examined.

RESULTS

MYH11 was downregulated in GC and predicted poor prognoses. MYH11 reverted the malignant phenotype of GC cells. MYH11 repressed the TNFRSF14 expression by binding to the TNFRSF14 promoter. TNFRSF14 reversed the inhibitory effect of MYH11 on the malignant phenotype of GC cells. The methylation of the MYH11 promoter was elevated in GC, which was correlated with the elevated DNMT3B in GC. Overexpression of DNMT3B repressed transcription of MYH11 by promoting its methylation. Also, MYH11 upregulation inhibited tumor growth.

CONCLUSION

DNMT3B inhibits MYH11 expression by promoting its DNA methylation, thereby attenuating the repressive effect of MYH11 on the transcriptional of TNFRSF14 and promoting the progression of GC.

Multimarker profiling identifies protective and harmful immune processes in heart failure: findings from BIOSTAT-CHF

Aims

The exploration of novel immunomodulatory interventions to improve outcome in heart failure (HF) is hampered by the complexity/redundancies of inflammatory pathways, which remain poorly understood. We thus aimed to investigate the associations between the activation of diverse immune processes and outcomes in patients with HF.

Methods and results

We measured 355 biomarkers in 2022 patients with worsening HF and an independent validation cohort (n = 1691) (BIOSTAT-CHF index and validation cohorts), and classified them according to their functions into biological processes based on the gene ontology classification. Principal component analyses were used to extract weighted scores per process. We investigated the association of these processes with all-cause mortality at 2-year follow-up. The contribution of each biomarker to the weighted score(s) of the processes was used to identify potential therapeutic targets. Mean age was 69 (±12.0) years and 537 (27%) patients were women. We identified 64 unique overrepresented immune-related processes representing 188 of 355 biomarkers. Of these processes, 19 were associated with all-cause mortality (10 positively and 9 negatively). Increased activation of ‘T-cell costimulation’ and ‘response to interferon-gamma/positive regulation of interferon-gamma production’ showed the most consistent positive and negative associations with all-cause mortality, respectively, after external validation. Within T-cell costimulation, inducible costimulator ligand, CD28, CD70, and tumour necrosis factor superfamily member-14 were identified as potential therapeutic targets.

Conclusions

We demonstrate the divergent protective and harmful effects of different immune processes in HF and suggest novel therapeutic targets. These findings constitute a rich knowledge base for informing future studies of inflammation in HF.

BTLA/HVEM Axis Induces NK Cell Immunosuppression and Poor Outcome in Chronic Lymphocytic Leukemia

Simple Summary

Chronic lymphocytic leukemia (CLL) represents the most frequent B cell malignancy in Western countries and still remains as an incurable disease. Despite recent advances in targeted therapies including ibrutinib, idelalisib or venetoclax, resistance mechanisms have been described and patients develop a progressive immunosuppression. Since immune checkpoint blockade has demonstrated to reinvigorate T and NK cell-mediated anti-tumor responses, the aim of this work was to elucidate whether this immunosuppression relies, at least in part, in BTLA/HVEM axis in patients with CLL. Our results demonstrate that BTLA and HVEM expression is deeply dysregulated on leukemic and NK cells and correlates with poor outcome. Moreover, soluble BTLA levels correlated with adverse cytogenetics and shorter time to treatment. BTLA blockade restored, at least in part, NK cell-mediated responses in patients with CLL. Altogether, our results provide the rationale to further investigate the role of BTLA/HVEM axis in the pathogenesis of CLL.

Abstract

Chronic lymphocytic leukemia (CLL) is characterized by progressive immunosuppression and diminished cancer immunosurveillance. Immune checkpoint blockade (ICB)-based therapies, a major breakthrough against cancer, have emerged as a powerful tool to reinvigorate antitumor responses. Herein, we analyzed the role of the novel inhibitory checkpoint BTLA and its ligand, HVEM, in the regulation of leukemic and natural killer (NK) cells in CLL. Flow cytometry analyses showed that BTLA expression is upregulated on leukemic cells and NK cells from patients with CLL, whereas HVEM is downregulated only in leukemic cells, especially in patients with advanced Rai-Binet stage. In silico analysis revealed that increased HVEM, but not BTLA, mRNA expression in leukemic cells correlated with diminished overall survival. Further, soluble BTLA (sBTLA) was found to be increased in the sera of patients with CLL and highly correlated with poor prognostic markers and shorter time to treatment. BTLA blockade with an anti-BTLA monoclonal antibody depleted leukemic cells and boosted NK cell-mediated responses ex vivo by increasing their IFN-γ production, cytotoxic capability, and antibody-dependent cytotoxicity (ADCC). In agreement with an inhibitory role of BTLA in NK cells, surface BTLA expression on NK cells was associated with poor outcome in patients with CLL. Overall, this study is the first to bring to light a role of BTLA/HVEM in the suppression of NK cell-mediated immune responses in CLL and its impact on patient’s prognosis, suggesting that BTLA/HVEM axis may be a potential therapeutic target in this disease.

Profiling of inhibitory immune checkpoints in glioblastoma: Potential pathogenetic players

Glioblastoma (GBM) represents the most frequent glial tumor, with almost 3 new cases per 100,000 people per year. Despite treatment, the prognosis for GBM patients remains extremely poor, with a median survival of 14.6 months, and a 5-year survival less than 5%. It is generally believed that GBM creates a highly immunosuppressive microenvironment, sustained by the expression of immune-regulatory factors, including inhibitory immune checkpoints, on both infiltrating cells and tumor cells. However, the trials assessing the efficacy of current immune checkpoint inhibitors in GBM are still disappointing. In the present study, the expression levels of several inhibitory immune checkpoints in GBM (CD276, VTCN1, CD47, PVR, TNFRSF14, CD200, LGALS9, NECTIN2 and CD48) were characterized in order to evaluate their potential as prognostic and eventually, therapeutic targets. Among the investigated immune checkpoints, TNFRSF14 and NECTIN2 were identified as the most promising targets in GBM. In particular, a higher TNFRSF14 expression was associated with worse overall survival and disease-free survival, and with a lower Th1 response.

Primary superficial Ewing sarcoma: A unique entity? A case report including novel findings of ELF3 and TNFRSF14 copy number loss

Primary superficial Ewing sarcoma (psES) cases are exceedingly rare, with fewer than 150 cases reported in the literature. Small case series have suggested differences between psES and Ewing sarcoma (ES) of bone or deep soft tissues: psES appears to have a more indolent course and a higher 5-year overall survival rate. PsES is more common in older adolescent females as opposed to younger males in their peak growth velocity years in bone or deep soft tissue ES. We present a case report of a 17-year-old female with a relatively static nodule on her left thigh for 4 years. Morphologic, immunohistochemical, and molecular evaluations confirmed ES. Patient underwent a gross-total resection and a shortened course of adjuvant chemotherapy without radiation. Cancer gene panel testing found three gene abnormalities (in addition to EWSR1-FLI1 fusion): CCND1 copy number gain, ELF3 copy number loss, and TNFRSF14 copy number loss. To our knowledge, this is the first published case report of psES to include genomic sequencing and the first to report ELF3 and TNFRSF14 abnormalities in ES. Larger series of psES cases with genomic profiling are needed to elucidate a possible genetic etiology for its more indolent clinical course and favorable outcomes.

Increased expression of the TNF superfamily member LIGHT/TNFSF14 and its receptors (HVEM and LTßR) in patients with systemic sclerosis

OBJECTIVES

This study aimed to assess the potential role of the TNF superfamily member lymphocyte T-related inducible ligand that competes for glycoprotein D binding to herpesvirus entry mediator on T cells (LIGHT) in SSc through evaluation of: skin expression of LIGHT and its receptors, herpesvirus entry mediator and lymphotoxin ß-related receptor, and serum concentration of LIGHT in SSc patients.

METHODS

Expression of LIGHT and its receptors was investigated by immunohistochemistry and evaluated semi-quantitatively in skin biopsies from 19 SSc patients and 9 healthy controls. Serum levels of LIGHT were measured using ELISA in 329 patients with SSc and 50 control subjects.

RESULTS

Expression of LIGHT and both receptors was higher in SSc patients compared with controls (P < 0.05 for all comparisons). Patients with early SSc (⩽ 3 years from the first non-Raynaud's phenomenon symptom) showed higher expression of LIGHT and herpesvirus entry mediator compared with patients with longer disease duration (P < 0.05 for both comparisons). The mean serum concentration of LIGHT was significantly higher in SSc patients compared with the controls (P < 0.05). High serum concentration of LIGHT was associated with male sex, presence of digital ulcers, muscle involvement (defined by elevated serum creatine kinase levels), steroid treatment and lack of ACA. However, in multivariate regression analysis only presence of digital ulcers and creatine kinase elevation were independently associated with serum concentration of LIGHT.

CONCLUSION

These data provide the first evidence of overexpression of LIGHT and its receptors in SSc and suggest that the LIGHT axis might contribute to the pathogenesis of SSc. Increased serum concentrations of LIGHT seem to reflect vascular injury in SSc.

Prediction of steroid demand in the treatment of patients with ulcerative colitis by immunohistochemical analysis of the mucosal microenvironment and immune checkpoint: role of macrophages and regulatory markers in disease severity

We aimed to characterize the mucosal immune microenvironment and immune checkpoint of Ulcerative colitis (UC) by immunohistochemistry with correlation to prognosis: requirement of second-line steroid-therapy within the 2-years after diagnosis (SR). A series of 72 cases included 56 UC, 43 non-SR (with first-line treatment 5-ASA) and 13 SR, 11 infectious colitis and 5 normal colonic biopsies. Normal mucosa was characterized by low infiltrates but high BTLA and TNFRSF14. Compared to normal, UC had increased pan-immune-markers of CD3, CD8, FOXP3, PD-1, CD68, CD16, CD163, PTX3 and CD11C but had decreased BTLA (P < 0.05); by GSEA analysis comparable results were found in an independent UC gene-expression-data set (GSE38713). Compared to infectious, UC had higher CD4, CD8, PTX3 and CD11C but lower BTLA (P < 0.05). Compared to non-SR, SR had lower FOXP3 + Tregs (Odds-Ratio = 0.114, P = 0.002), PD-1 (OR = 0.176, P = 0.002) and CD163/CD68 M2-ratio (OR, 0.019, P = 0.019) but higher CD68 + pan-macrophages (OR = 6.034, P = 0.002). Higher Baron endoscopic and Geboes histologic disease activity scores also correlated with SR. In summary, UC was characterized by increased pan-immune-markers, normal TNFRSF14 and low BTLA. SR had increased CD68 + pan-macrophages but lower immune inhibitors of FOXP3 + Tregs, PD-1 and CD163/CD68 M2-macrophage ratio. In conclusion, alterations of the immune homeostasis mechanisms are relevant in the UC pathogenesis and steroid-requiring situation.

Recurrent mutations in genes involved in nuclear factor-κB signalling in nodal marginal zone lymphoma-diagnostic and therapeutic implications

AIMS

To investigate the spectrum of mutations in 20 genes involved in B-cell receptor and/or Toll-like receptor signalling resulting in activation of nuclear factor-κB (NF-κB) in 20 nodal marginal zone lymphomas (NMZLs), 20 follicular lymphomas (FLs), and 11 cases of B-cell lymphoma, unclassifiable (BCL-u).

METHODS AND RESULTS

Nodal marginal zone lymphomas were diagnosed according to strict criteria, including the expression of at least one putative marginal zone marker (MNDA and/or IRTA1). Cases that showed features of NMZL but did not fulfil all criteria were included as BCL-u. All FLs were required to have a BCL2 rearrangement. Mutations were found in: nine NMZLs, with recurrent mutations in TNFAIP3 and CD79B; 12 FLs, with recurrent mutations in TNFRSF14, TNFAIP3, and CARD11; and five cases of BCL-u, with recurrent mutations in TNFRSF14. TNFRSF14 mutations were present in FL and BCL-u, but not in any of the NMZLs. In the BCL-u group, TNFRSF14 mutations clustered with a FL immunophenotype.

CONCLUSIONS

These results suggest that TNFRSF14 mutations point towards a diagnosis of FL, and can be used in the sometimes difficult distinction between NMZL and FL, but to apply this in diagnostics would require confirmation in an independent cohort. In addition, the presence or absence of specific mutations in pathways converging on NF-κB could be important for decisions regarding targeted treatment.

Clinical impact of herpesvirus entry mediator expression in human hepatocellular carcinoma

BACKGROUND

Herpes virus entry mediator (HVEM), also known as tumour necrosis factor receptor (TNFR) superfamily 14, regulates a variety of physiological and pathological responses in both innate and acquired immunity. Although HVEM is also suggested to be a critical regulator in tumours, actual roles in human cancer are largely unknown. This study aimed to clarify clinical importance of HVEM in human hepatocellular carcinoma (HCC).

PATIENTS AND METHODS

We studied HVEM expression in 150 HCC patients to explore its clinical relevance, and we examined tumour infiltrating T cells and local immune status of them.

RESULTS

HVEM was expressed in HCC cells, while no or only limited expression was observed in normal tissues in the liver. Tumour HVEM expression was significantly correlated with age, serum protein induced by vitamin K absence or antagonist-II (PIVKA-II) level, vascular invasion and tumour node metastasis (TNM) stage. Furthermore, tumour HVEM expression significantly correlated with postoperative recurrence and survival. Importantly, multivariate analysis indicated that the HVEM status had an independent prognostic value. Furthermore, HVEM status was inversely correlated with tumour-infiltrating CD4(+), CD8(+) and CD45RO(+) lymphocytes. In addition, it was also associated with reduced expression of perforin, granzyme B and interferon-γ (IFN-γ). Taken together, tumour-expressing HVEM plays a functionally important role in HCC.

CONCLUSION

Tumour-expressing HVEM plays a critical role in human HCC, possibly through regulating immune evasion. Therefore, targeting HVEM may be a novel promising therapeutic strategy for HCC.