B And T Lymphocyte Attenuator Research Articles

The Methylation in B7-H4 and BTLA Genes are Associated with the Risk of Pulmonary Tuberculosis.

The important roles of B7 homologous body 4 (B7-H4), B and T lymphocyte attenuator (BTLA) in patients with pulmonary tuberculosis (PTB) have been reported. This study aims to evaluate the association among B7-H4 and BTLA genes polymorphism, methylation and PTB susceptibility. Here, we assessed the possible relationship of 10 single nucleotide polymorphisms (SNPs) in B7-H4, BTLA genes with PTB susceptibility in a Chinese population (496 PTB patients and 502 controls) by SNPscan technique. Then, the B7-H4, BTLA genes methylation levels among 98 PTB patients and 97 controls were detected using MethylTarget technique. This study found no significant differences in allele and genotype frequencies of B7-H4 gene rs10754339, rs10801935, rs10923223, rs1937956, rs3738414, BTLA gene rs1982809, rs2971205, rs75368388, rs9288953 variants between PTB patients and controls. Haplotype analysis suggested that the lower frequencies of B7-H4 AATTG haplotype, BTLA GATT haplotype and the higher frequency of BTLA AGTC haplotype were found in PTB patients when compared with controls. We also found that the frequency of BTLA gene rs9288953 C allele was significantly increased in PTB patients with drug resistance. Moreover, the methylation levels of B7-H4 and BTLA genes in PTB patients were greater than that in controls, and rs10754339 variant in B7-H4 gene could affect its methylation level in PTB patients. B7-H4, BTLA genes polymorphism might not affect PTB susceptibility, while the abnormal methylation levels of B7-H4, BTLA genes were associated with the genetic background of PTB.

In vitro vascularized immunocompetent patient-derived model to test cancer therapies

This work describes a patient-derived tumoroid model (PDTs) to support precision medicine in lung oncology. The use of human adipose tissue-derived microvasculature and patient-derived peripheral blood mononuclear cells (PBMCs) permits to achieve a physiologically relevant tumor microenvironment. This study involved ten patients at various stages of tumor progression. The vascularized, immune-infiltrated PDT model could be obtained within two weeks, matching the requirements of the therapeutic decision. Histological and transcriptomic analyses confirmed that the main features from the original tumor were reproduced. The 3D tumor model could be used to determine the dynamics of response to antiangiogenic therapy and platinum-based chemotherapy. Antiangiogenic therapy showed a significant decrease in vascular endothelial growth factor (VEGF)-A expression, reflecting its therapeutic effect in the model. In an immune-infiltrated PDT model, chemotherapy showed the ability to decrease the levels of lymphocyte activation gene-3 protein (LAG-3), B and T lymphocyte attenuator (BTLA), and inhibitory receptors of Tcells functions.

Novel PD-L1/BTLA Checkpoint Axis Exploited for Bacterial Immune Escape by Restraining CD8+ T Cell-Initiated Adaptive Immunity in Zebrafish.

Programmed death-ligand 1/programmed cell death 1 (PD-L1/PD-1) is one of the most important immune checkpoints in humans and other mammalian species. However, the occurrence of the PD-L1/PD-1 checkpoint in evolutionarily ancient vertebrates remains elusive because of the absence of a PD-1 homolog before its appearance in tetrapods. In this article, we identified, to our knowledge, a novel PD-L1/B and T lymphocyte attenuator (BTLA) checkpoint in zebrafish by using an Edwardsiella tarda-induced bacterial infection model. Results showed that zebrafish (Danio rerio) PD-L1 (DrPD-L1) and BTLA (DrBTLA) were differentially upregulated on MHC class II+ macrophages (Mϕs) and CD8+ T cells in response to E. tarda infection. DrPD-L1 has a strong ability to interact with DrBTLA, as shown by the high affinity (KD = 5.68 nM) between DrPD-L1/DrBTLA proteins. Functionally, the breakdown of DrPD-L1/DrBTLA interaction significantly increased the cytotoxicity of CD8+BTLA+ T cells to E. tarda-infected PD-L1+ Mϕ cells and reduced the immune escape of E. tarda from the target Mϕ cells, thereby enhancing the antibacterial immunity of zebrafish against E. tarda infection. Similarly, the engagement of DrPD-L1 by soluble DrBTLA protein diminished the tolerization of CD8+ T cells to E. tarda infection. By contrast, DrBTLA engagement by a soluble DrPD-L1 protein drives aberrant CD8+ T cell responses. These results were finally corroborated in a DrPD-L1-deficient (PD-L1-/-) zebrafish model. This study highlighted a primordial PD-L1/BTLA coinhibitory axis that regulates CD8+ T cell activation in teleost fish and may act as an alternative to the PD-L1/PD-1 axis in mammals. It also revealed a previously unrecognized strategy for E. tarda immune evasion by inducing CD8+ T cell tolerance to target Mϕ cells through eliciting the PD-L1/BTLA checkpoint pathway.

Dual inhibition of BTLA and PD-1 can enhance therapeutic efficacy of paclitaxel on intraperitoneally disseminated tumors

BackgroundExpression of immune checkpoints in the tumor microenvironment is one mechanism underlying paclitaxel (PTX) chemoresistance. This study aimed to investigate whether the addition of checkpoint blockade to PTX can improve...

Stimulation of Immune Checkpoint Molecule B and T-Lymphocyte Attenuator Alleviates Experimental Crescentic Glomerulonephritis.

Treatment of acute, crescentic glomerulonephritis (GN) consists of unspecific and potentially toxic immunosuppression. T cells are central in the pathogenesis of GN, and various checkpoint molecules control their activation. The immune checkpoint molecule B and T-lymphocyte attenuator (BTLA) has shown potential for restraining inflammation in other T-cell-mediated disease models. To investigate its role in GN in a murine model of crescentic nephritis, the authors induced nephrotoxic nephritis in BTLA-deficient mice and wild-type mice. They found that BTLA has a renoprotective role through suppression of local Th1-driven inflammation and expansion of T regulatory cells and that administration of an agonistic anti-BTLA antibody attenuated experimental GN. These findings suggest that antibody-based modulation of BTLA may represent a treatment strategy in human glomerular disease. Modulating T-lymphocytes represents a promising targeted therapeutic option for glomerulonephritis (GN) because these cells mediate damage in various experimental and human GN types. The immune checkpoint molecule B and T-lymphocyte attenuator (BTLA) has shown its potential to restrain inflammation in other T-cell-mediated disease models. Its role in GN, however, has not been investigated. We induced nephrotoxic nephritis (NTN), a mouse model of crescentic GN, in Btla -deficient ( BtlaKO ) mice and wild-type littermate controls and assessed disease severity using functional and histologic parameters at different time points after disease induction. Immunologic changes were comprehensively evaluated by flow cytometry, RNA sequencing, and in vitro assays for dendritic cell and T-cell function. Transfer experiments into Rag1KO mice confirmed the observed in vitro findings. In addition, we evaluated the potential of an agonistic anti-BTLA antibody to treat NTN in vivo . The BtlaKO mice developed aggravated NTN, driven by an increase of infiltrating renal Th1 cells. Single-cell RNA sequencing showed increased renal T-cell activation and positive regulation of the immune response. Although BTLA-deficient regulatory T cells (Tregs) exhibited preserved suppressive function in vitro and in vivo , BtlaKO T effector cells evaded Treg suppression. Administration of an agonistic anti-BTLA antibody robustly attenuated NTN by suppressing nephritogenic T effector cells and promoting Treg expansion. In a model of crescentic GN, BTLA signaling effectively restrained nephritogenic Th1 cells and promoted regulatory T cells. Suppression of T-cell-mediated inflammation by BTLA stimulation may prove relevant for a broad range of conditions involving acute GN.

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.

BTLA transcriptomic expression correlates with high levels of PD-1, PD-L2, and CTLA-4 checkpoints and with its ligand, HVEM, across diverse solid cancers.

e14641 Background: B and T lymphocyte attenuator (BTLA) is an immune checkpoint that is highly expressed on tumor-specific T cells and has been shown to be upregulated in several cancer types. The binding of BTLA to its ligand herpesvirus entry mediator (HVEM, also known as TNFRSF14) inhibits activation and proliferation of T lymphocytes, leading to decreased tumor killing. Early clinical trials of BTLA inhibitors are ongoing with preliminary results showing modest effects in advanced solid tumors. More recent clinical data suggests that combination checkpoint therapy with anti-BTLA and anti-PD-1 treatment provides greater benefit compared to monotherapy in patients with lymphoma. Methods: We analyzed RNA expression levels of 397 genes in various solid tumor types from 514 patients with various types of solid tumors seen at University of San Diego (UCSD), Moores Cancer Center. RNA expression was quantified at a CLIA-approved laboratory Omniseq (https://www.omniseq.com). Transcript abundance was normalized to internal housekeeping gene profiles and ranked (0-100 percentile) in a standardized manner to a reference population of 735 tumors spanning 35 histologies. We analyzed tumors with “High” (75-100 percentile rank) BTLA expression profiles. Odds ratio for high BTLA expression was calculated and multivariate analysis was utilized to determine significant correlations for multiple genes. Results: A total of 96 (18.7%) tumors had high BTLA (>75) expression across 32 different histologies. Cancers with the highest proportion of BTLA expression were small intestine (42%), breast (31%), pancreatic (29%), stomach (24%), neuroendocrine (20%), lung (20%), head and neck (17%) and colorectal (13%). There was significant association for BTLA and high PD-1 (p < 0.001), high CTLA-4 (p < 0.001), high PD-L2 (p = 0.05) and its ligand HVEM (p < 0.01). There was no significant association between BTLA expression and PD-L1, gender or stomach, neuroendocrine, head and neck, and lung histologies. Conclusions: High BTLA expression was found in a large number of tumor samples and significantly associated with other immune checkpoints with FDA-approved drugs. Furthermore, HVEM expression (ligand for BTLA) significantly correlates with high BTLA transcriptome levels. The BTLA/HVEM pathway has been associated with suppression of T cell-mediated anti-tumor activity and resistance to anti-PD-1 immunotherapy leading to poor clinical outcomes. The utilization of combination checkpoint therapy involving BTLA inhibitors and specific checkpoint blockade is currently being explored. Our results suggest that patient selection based on the RNA expression level of immune markers matched to corresponding immunotherapy agent, rather than a population-based approach, may be ideal for optimizing treatment response.

Phase I/II combination study of tifcemalimab with toripalimab in patients with refractory extensive stage small cell lung cancer (ES-SCLC).

8579 Background: The B- and T-lymphocyte attenuator (BTLA) is a novel inhibitory co-signaling receptor expressed on B cell, T cells and NK cells. Co-blockade of the BTLA and PD-1 pathways improved antigen specific anti-tumor T cell response. Tifcemalimab (JS004 or TAB004) is a humanized IgG4 monoclonal antibody with a hinge mutation (S228P) that binds BTLA and blocks its interaction with its ligand HVEM. In previous phase I studies, tifcemalimab has shown preliminary anti-tumor activities as monotherapy or in combination with toripalimab (anti-PD-1) with a manageable safety profile in patients with advanced malignancies. Methods: Eligible ES-SCLC patients refractory to prior therapies were enrolled in this I/II study (NCT05000684). Patients received 200mg tifcemalimab and 240mg toripalimab intravenously once every three weeks until disease progression, intolerable toxicity or 2 years of treatment. Study objectives included safety, anti-tumor activity and correlative biomarkers. Results: As of Jan 31, 2023, a total of 43 ES-SCLC patients refractory to prior therapy were enrolled. The median age was 60.0 (range 38-75) years. The median prior line of therapy was 1 and 14 (32.6%) patients received prior anti-PD-1/L1 treatment. By the cut-off date, the median follow-up duration was 12.1 weeks. Thirty-two (74.4%) patients experienced treatment-emergent adverse events (TEAEs); 12 (27.9%) patients experienced grade ≥ 3 TEAEs. The most common TEAEs were hyponatraemia (16.3%), alanine aminotransferase increased (14%), aspartate aminotransferase increased (14%), and blood creatine phosphokinase increased (14%). Three (7.0%) patients experienced treatment-related adverse events (TRAEs) led to interruption of study drugs and no TRAEs led to discontinuation of study drugs were reported. Fifteen (34.9%) patients experienced immune related AE (irAEs), and 2 (4.7%) patients experienced grade ≥ 3 irAEs. Among 38 efficacy evaluable patients, the ORR was 26.3% and the DCR was 57.9%. The ORR was 8.3% in immunotherapy treated patients and 40.0% in immunotherapy naïve patients. By the cut-off date, 70.0% of the responses were ongoing and the median duration of response was not reached. Tumor expression of HVEM and PD-L1 was evaluated to explore the correlation with clinical response. Conclusions: Tifcemalimab in combination with toripalimab were well tolerated in patients with refractory ES- SCLC. Further clinical evaluation of this combination treatment in SCLC is warranted. Clinical trial information: NCT05000684 .

Low plasma PD-L1 levels, early tumor onset and absence of peritoneal carcinomatosis improve prognosis of women with advanced high-grade serous ovarian cancer

BackgroundThe most common subtype of ovarian cancer (OC) showing immunogenic potential is represented by the high-grade serous ovarian cancer (HGSOC), which is characterized by the presence of tumor-infiltrating immune cells able to modulate immune response. Because several studies showed a close correlation between OC patient’s clinical outcome and expression of programmed cell death protein-1 or its ligand (PD-1/PD-L1), the aim of our study was to investigate if plasma levels of immunomodulatory proteins may predict prognosis of advanced HGSOC women.Patients and methodsThrough specific ELISA tests, we analyzed plasma concentrations of PD-L1, PD-1, butyrophilin sub-family 3A/CD277 receptor (BTN3A1), pan-BTN3As, butyrophilin sub-family 2 member A1 (BTN2A1), and B- and T-lymphocyte attenuator (BTLA) in one hundred patients affected by advanced HGSOC, before surgery and therapy. The Kaplan–Meier method was used to generate the survival curves, while univariate and multivariate analysis were performed using Cox proportional hazard regression models.ResultsFor each analyzed circulating biomarker, advanced HGSOC women were discriminated based on long (≥ 30 months) versus short progression-free survival (PFS < 30 months). The concentration cut-offs, obtained by receiver operating characteristic (ROC) analysis, allowed to observe that poor clinical outcome and median PFS ranging between 6 and 16 months were associated with higher baseline levels of PD-L1 (> 0.42 ng/mL), PD-1 (> 2.48 ng/mL), BTN3A1 (> 4.75 ng/mL), pan-BTN3As (> 13.06 ng/mL), BTN2A1 (> 5.59 ng/mL) and BTLA (> 2.78 ng/mL). Furthermore, a lower median PFS was associated with peritoneal carcinomatosis, age at diagnosis > 60 years or Body Mass Index (BMI) > 25. A multivariate analysis also suggested that plasma concentrations of PD-L1 ≤ 0.42 ng/mL (HR: 2.23; 95% CI: 1.34 to 3.73; p = 0.002), age at diagnosis ≤ 60 years (HR: 1.70; 95% CI: 1.07 to 2.70; p = 0.024) and absence of peritoneal carcinomatosis (HR: 1.87; 95% CI: 1.23 to 2.85; p = 0.003) were significant prognostic marker for a longer PFS in advanced HGSOC patients.ConclusionsThe identification of high-risk HGSOC women could be improved through determination of the plasma PD-L1, PD-1, BTN3A1, pan-BTN3As, BTN2A1 and BTLA levels.

Anti-HVEM mAb therapy improves antitumoral immunity both in vitro and in vivo, in a novel transgenic mouse model expressing human HVEM and BTLA molecules challenged with HVEM expressing tumors

BackgroundTumor necrosis factor superfamily member 14 (TNFRSF14)/herpes virus entry mediator (HVEM) is the ligand for B and T lymphocyte attenuator (BTLA) and CD160-negative immune co-signaling molecules as well as viral...

Targeting immune checkpoints in anti-neutrophil cytoplasmic antibodies associated vasculitis: the potential therapeutic targets in the future.

Anti-neutrophil cytoplasmic autoantibodies (ANCA) associated vasculitis (AAV) is a necrotizing vasculitis mainly involving small blood vessels. It is demonstrated that T cells are important in the pathogenesis of AAV, including regulatory T cells (Treg) and helper T cells (Th), especially Th2, Th17, and follicular Th cells (Tfh). In addition, the exhaustion of T cells predicted the favorable prognosis of AAV. The immune checkpoints (ICs) consist of a group of co-stimulatory and co-inhibitory molecules expressed on the surface of T cells, which maintains a balance between the activation and exhaustion of T cells. CD28, inducible T-cell co-stimulator (ICOS), OX40, CD40L, glucocorticoid induced tumor necrosis factor receptor (GITR), and CD137 are the common co-stimulatory molecules, while the programmed cell death 1 (PD-1), cytotoxic T lymphocyte-associated molecule 4 (CTLA-4), T cell immunoglobulin (Ig) and mucin domain-containing protein 3 (TIM-3), B and T lymphocyte attenuator (BTLA), V-domain Ig suppressor of T cell activation (VISTA), T-cell Ig and ITIM domain (TIGIT), CD200, and lymphocyte activation gene 3 (LAG-3) belong to co-inhibitory molecules. If this balance was disrupted and the activation of T cells was increased, autoimmune diseases (AIDs) might be induced. Even in the treatment of malignant tumors, activation of T cells by immune checkpoint inhibitors (ICIs) may result in AIDs known as rheumatic immune-related adverse events (Rh-irAEs), suggesting the importance of ICs in AIDs. In this review, we summarized the features of AAV induced by immunotherapy using ICIs in patients with malignant tumors, and then reviewed the biological characteristics of different ICs. Our aim was to explore potential targets in ICs for future treatment of AAV.

The association of BTLA gene polymorphisms with non-small lung cancer risk in smokers and never-smokers.

Lung cancer is the predominant cause of death among cancer patients and non-small cell lung cancer (NSCLC) is the most common type. Cigarette smoking is the prevailing risk factor for NSCLC, nevertheless, this cancer is also diagnosed in never-smokers. B and T lymphocyte attenuator (BTLA) belongs to immunological checkpoints which are key regulatory molecules of the immune response. A growing body of evidence highlights the important role of BTLA in cancer. In our previous studies, we showed a significant association between BTLA gene variants and susceptibility to chronic lymphoblastic leukemia and renal cell carcinoma in the Polish population. The present study aimed to analyze the impact of BTLA polymorphic variants on the susceptibility to NSCLC and NSCLC patients' overall survival (OS). Using TaqMan probes we genotyped seven BTLA single-nucleotide polymorphisms (SNPs): rs2705511, rs1982809, rs9288952, rs9288953, rs1844089, rs11921669 and rs2633582 with the use of ViiA 7 Real-Time PCR System. We found that rs1982809 within BTLA is associated with NSCLC risk, where carriers of rs1982809G allele (AG+GG genotypes) were more frequent in patients compared to controls. In subgroup analyses, we also noticed that rs1982809G carriers are significantly overrepresented in never-smokers, but not in smokers compared to controls. Additionally, the global distribution of the haplotypes differed between the never-smokers and smokers, where haplotypes A G G C A, C G A C G, and C G A T G were more frequent in never-smoking patients. Furthermore, the presence rs1982809G (AG+GG genotypes) allele as well as the presence of rs9288953T allele (CT+TT genotypes) increased NSCLC risk in females' patients. After stratification by histological type, we noticed that rs1982809G and rs2705511C carriers were more frequent among adenocarcinoma patients. Moreover, rs1982809G and rs2705511C correlated with the more advanced stages of NSCLC (stage II and III), but not with stage IV. Furthermore, we showed that rs2705511 and rs1982809 significantly modified OS, while rs9288952 tend to be associated with patients' survival. Our results indicate that BTLA polymorphic variants may be considered low penetrating risk factors for NSCLC especially in never-smokers, and in females, and are associated with OS of NSCLC patients.

A pan-cancer analysis of the biological function and clinical value of BTLA in tumors

B and T-lymphocyte attenuator (BTLA) plays an immunosuppressive role by inhibiting T- and B-cell functions. BTLA is associated with a variety of diseases, especially cancer immunity. However, the function of BTLA in various cancers and its clinical prognostic value have still not been comprehensively analyzed. This study aimed to identify the relationship between BTLA and cancer from the perspectives of differences in BTLA expression, its clinical value, immune infiltration, and the correlation with immune-related genes in various cancers. Data regarding mRNA expression, miRNA expression, lncRNA expression, and clinical data of patients of 33 existing cancers were collected from the TCGA database. Target miRNA of BTLA and the lncRNA that interacts with the target miRNA were obtained from the StarBase database. Based on bioinformatics analysis methods, the relationship between various types of cancers and BTLA was thoroughly investigated, and a competing endogenous RNA network of BTLA, target miRNA, and interacting lncRNA was constructed. The Kaplan-Meier (KM) prognostic analysis of BTLA and target miRNA (has-miR-137) in various types of cancers was completed using the KM plotter. BTLA expression varied in different cancers, with statistical significance in nine cancer types. KM plotter to analyze the overall survival (OS) and regression-free survival prognosis of cancer patients revealed that the BTLA expression was statistically different in the OS of 11 types of cancers out of 21 types of cancers; the OS of 8 type of cancers was also statistically different. Correlation analysis of tumor immune genes revealed a positive correlation of BTLA expression with immunosuppressive gene (CTLA4 and PDCD1) expression. Gene Set Enrichment Analysis showed that BTLA and its co-expressed genes mainly act through biological processes and pathways, including immune response regulation, cell surface receptor signaling pathway, antigen binding, antigen receptor-mediated signaling pathway, and leukocyte migration. BTLA has the potential as a prognostic marker for CLL, COAD, NSCLC, and OV and a diagnostic marker for CLL, COAD, and KIRC. BTLA has a close and complex relationship with the occurrence and development of tumors, and cancer immunotherapy for BTLA is worthy of further analysis.

Tumor Cell-Intrinsic BTLA Receptor Inhibits the Proliferation of Tumor Cells via ERK1/2

B and T lymphocyte attenuator (BTLA) is an immune checkpoint molecule that mediates the escape of tumor cells from immunosurveillance. Consequently, BTLA and its ligand herpesvirus entry mediator (HVEM) are potentially immunotherapeutic targets. However, the potential effects of BTLA on tumor cells remain incompletely unknown. Here, we show that BTLA is expressed across a broad range of tumor cells. The depletion of BTLA or HVEM promotes cell proliferation and colony formation, which is reversed by the overexpression of BTLA in BTLA knockout cells. In contrast, overexpression of BTLA or HVEM inhibits tumor cell proliferation and colony formation. Furthermore, the proliferation of a subpopulation with high BTLA was also significantly slower than that of the low BTLA subpopulation. Mechanistically, the coordination of BTLA and HVEM inhibits its major downstream extracellular regulated protein kinase (ERK1/2) signaling pathway, thus preventing tumor cell growth. This study demonstrates that tumor cell-intrinsic BTLA/HVEM is a potential tumor suppressor and is likely to have a potential antagonist for immunotherapy, thus representing a potential biomarker for the optimal cancer immunotherapeutic treatment.

B and T lymphocyte attenuator as a C-reactive protein and IgA associated auxiliary diagnostic marker for pulmonary tuberculosis: a case-control study.

Screening and identification of hematologic molecular indicators of pulmonary tuberculosis (PTB) is crucial for its diagnose and therapy. Therefore, our work aims to detect the diagnostic value of blood marker B and T lymphocyte attenuator (BTLA) in PTB, and provide a certain theoretical basis for the auxiliary diagnosis of PTB. Based on the inclusion criteria, 56 Patients with clinically confirmed pulmonary TB by clinical between January 2020 and December 2021 at our hospital were selected as the research objects of this study. Fifty-two matched healthy population at our hospital was used as the control group. Clinical characteristics were got from clinical laboratory. Real-time polymerase chain reaction (RT-PCR) was used to analyze changes in BTLA along with its ligand in peripheral blood. Changes in BTLA on the surface of different cells were analyzed by flow cytometry. The correlation test was used to determine the associations between BTLA and clinical indicators. Receiver operating characteristic (ROC) curve analysis was used to evaluate the auxiliary diagnostic value in PTB of BTLA expression from different sources. Compared with the control, changes in peripheral blood BTLA in the PTB group were significantly increased (P=0.0187) rather than its ligand. Changes in BTLA on the surface of CD68 and antigen-presenting cell (APC) CD11c were significantly increased in the PTB group (P=0.0004, P<0.0001), while changes in BTLA on the surface of CD4+ T and CD8+ T cells were not significantly different (P=0.0792, P=0.8706). The expression of BTLA+CD11c+ was negatively correlated with the expression of immunoglobulin A (IgA) (r=-0.2934, P=0.0282) and positively related to C-reactive protein (r=0.3277, P=0.0137). ROC curve analysis suggested that the area under the curve (AUC), sensitivity and specificity of BTLA RT-PCR detection were 0.6315, 53.57%, 57.69% while for BTLA+CD11c+ detection were 0.8039, 88.46% and 73.21% and for BTLA+CD68+ detection were 0.6973, 60.71% and 61.54%. BTLA is highly expressed in peripheral blood and specific cell types of patients with PTB and is correlated with specific clinical indicators, which may be an important molecular marker for the auxiliary diagnosis of PTB.

Phase I Study of the Anti-Btla Antibody Tifcemalimab As a Single Agent or in Combination with Toripalimab in Relapsed/Refractory Lymphomas

Background: The B- and T-lymphocyte attenuator (BTLA) is an inhibitory receptor expressed on B, T and NK cells. Using Peripheral Blood Mononuclear Cell (PBMC) derived from cancer patients, co-blockade of the BTLA and PD-1 pathways improved antigen specific T cell response compared to either blockade alone. Tifcemalimab (also known as icatolimab, JS004 or TAB004) is a humanized IgG4 monoclonal antibody with a hinge mutation (S228P) that binds BTLA and blocks its interaction with its ligand Herpesvirus Entry Mediator (HVEM). In this first-in-human study, we report the preliminary safety and anti-tumor activity of tifcemalimab as a single agent or in combination with toripalimab (anti-PD-1) in patients with relapsed/refractory (R/R) lymphoma. Methods: Eligible patients with R/R lymphoma were enrolled in this open-label, multicenter study (NCT04477772). Tifcemalimab was administered as a monotherapy at escalating doses of 1, 3 and 10 mg/kg intravenously Q3W, followed by 3 mg/kg and 200 mg monotherapy dose expansion until disease progression or intolerable toxicity. During combination dose escalation, patients received ascending doses of tifcemalimab (100mg and 200mg) plus toripalimab (240mg). Dose-limiting toxicity (DLT) was evaluated by a safety monitoring committee. Study objectives included safety, pharmacokinetics, and efficacy. Results: By the cutoff date of July 21, 2022, a total of 48 patients were enrolled, including 25 in the monotherapy and 23 in the combination subgroup. The lymphoma subtypes included 28 Hodgkin's lymphoma (HL) and 20 non-Hodgkin's lymphoma. The median age was 43.5 (range 19-70) years with 33 (68.8%) male patients. The median prior line of therapy was 4 with 32 (66.7%) progressed upon prior anti-PD-1/L1 therapy. By the cutoff date, the median follow-up was 31.3 weeks. No DLT was observed in either monotherapy or combination dose escalation. Forty-one (83.3%) patients experienced treatment emergent adverse events (TEAEs), 9 (18.8%) of whom experienced grade 3 or above TEAEs. The most common TEAEs were fever (27.1%) and anemia (25.0%). Five treatment-related adverse events led to the discontinuation of the study drug. Ten (40.0%) and 13(56.5%) patients experienced immune related AEs in the monotherapy and combination subgroups, respectively, but all were grade 1 or 2. Among 22 evaluable patients receiving monotherapy, 1 PR (follicular lymphoma) and 7 SD were observed per Lugano criteria. Among all evaluable HL patients receiving the combination regimen (n=12), 1 CR, 4 PR (ORR 41.7%) and 5 SD (DCR 83.3%) were observed. Among them, 11 (91.7%) and 7 (58.3%) patients were refractory to prior anti-PD-1/L1 or anti-CD30 therapy, respectively. The clinical efficacy is durable as all responses are ongoing by the cutoff date, with the duration of response ranges from 2+ to 8+ months. Preliminary data showed a trend of correlation between high HVEM expression and clinical response. Conclusions: Tifcemalimab alone or in combination with toripalimab were well tolerated in all doses evaluated. The combination showed encouraging preliminary clinical efficacy in patients with R/R HL refractory to anti-PD-1/L1 and/or anti-CD30.

PDGFR kinase inhibitor protects against septic death via regulation of BTLA.

Sepsis, defined as life-threatening organ failure caused by a dysregulated host response to severe infection, is a major cause of death among intensive care unit patients. Therapies targeting on immunomodulatory is a new research field in sepsis treatment. B- and T-lymphocyte attenuator (BTLA) is an inhibitory costimulatory factor molecule of B and T lymphocytes. Studies have shown that elevated expression of BTLA in lymphocytes can reduce mortality in sepsis, but its regulatory compounds and the underlying mechanism remains to be elucidated. Here, we show that treatment with CP-673451 significantly decreases mortality of septic mouse. CP-673451 is a PDGFR kinase inhibitor which can promote the expression of BTLA, inhibit the release of chemokines such as CXCL13, and reduce first the chemotaxis of B cells to the peripheral blood and vital organs. CP-673451 also inhibits both the release of cytokines and chemokines such as IL-1β, IL-6, IL-10, TNF-α, CCL1, CCL2 and CCL7 and reduces both the chemotactic ability of T cells. This suggests that CP-673451 may prevent septic death by inhibiting lymphocyte chemotaxis and alleviating “cytokine storm”. In conclusion, our study provides a new therapeutic target and an effective compound for sepsis treatment.Supporting InformationThe supporting information is available online at 10.1007/s11427-021-2136-y. The supporting materials are published as submitted, without typesetting or editing. The responsibility for scientific accuracy and content remains entirely with the authors.

Decreased frequency of a novel T-lymphocyte subset, CD3+ CD4- CD7+ CD57- T cells, in hepatitis B virus-related end-stage liver disease might contribute to disease progression.

CD7 and CD57 are related to the differentiation and functional stages of CD8+ T cells. However, the role of their combined presence in CD8+ T cells in patients with chronic hepatitis B virus (HBV) infection, especially those with end-stage liver disease, remains unclear. Blood samples from healthy volunteers and patients with chronic hepatitis B were analyzed via Luminex assay and ELISA to measure plasma cytokine levels. Further, recombinant IL-22 was used to stimulate peripheral blood mononuclear cells from healthy volunteers, and the frequency of CD3+ CD4- CD7+ CD57- T cells and apoptosis rates were investigated via flow cytometry. Patients with end-stage liver disease, particularly those with acute to chronic liver failure, showed decreased CD3+ CD4- CD7+ CD57- T cell frequency. Furthermore, the prevalence of CD3+ CD4- CD7+ CD57- T cells was negatively correlated with disease severity, prognosis, and complications (ascites). We also observed that IL-22 promoted apoptosis and brought about a decrease in the number of CD3+ CD4- CD7+ CD57- T cells in a dose-dependent manner. CD3+ CD4- CD7+ CD57- T cells displayed a B and T lymphocyte attenuator(BTLA)high CD25high CD127high immunosuppressive phenotype and showed low interferon-γ, tumor necrosis factor-α, granzyme A, and perforin expression levels. The present findings will elucidate the pathogenesis of HBV-related end-stage liver disease and aid the identification of novel drug targets.

Can circulating PD-1, PD-L1, BTN3A1, pan-BTN3As, BTN2A1 and BTLA levels enhance prognostic power of CA125 in patients with advanced high-grade serous ovarian cancer?

The most common subtype of ovarian cancer (OC) is the high-grade serous ovarian carcinoma (HGSOC), accounting for 70%–80% of all OC deaths. Although HGSOC is a potentially immunogenic tumor, clinical studies assessing the effectiveness of inhibitors of programmed death protein and its ligand (PD-1/PD-L1) in OC patients so far showed only response rates <15%. However, recent studies revealed an interesting prognostic role of plasma PD-1/PD-L1 and other circulating immunoregulatory molecules, such as the B- and T-lymphocyte attenuator (BTLA), butyrophilin sub-family 3A/CD277 receptors (BTN3A), and butyrophilin sub-family 2 member A1 (BTN2A1), in several solid tumors. Since evidence showed the prognostic relevance of pretreatment serum CA125 levels in OC, the aim of our study was to investigate if soluble forms of inhibitory immune checkpoints can enhance prognostic power of CA125 in advanced HGSOC women. Using specific ELISA tests, we examined the circulating PD-1, PD-L1, pan-BTN3As, BTN3A1, BTN2A1, and BTLA levels in 100 advanced HGSOC patients before treatment, correlating them with baseline serum CA125, age at diagnosis, body mass index (BMI), and peritoneal carcinomatosis. A multivariate analysis revealed that plasma BTN3A1 ≤4.75 ng/ml (HR, 1.94; 95% CI, 1.23–3.07; p=0.004), age at diagnosis ≤60 years (HR, 1.65; 95% CI, 1.05–2.59; p=0.03) and absence of peritoneal carcinomatosis (HR, 2.65; 95% CI, 1.66–4.22; p<0.0001) were independent prognostic factors for a longer progression-free survival (PFS) (≥30 months) in advanced HGSOC women. However, further two-factor multivariate analyses highlighted that baseline serum CA125 levels >401 U/ml and each soluble protein above respective concentration cutoff were covariates associated with shorter PFS (<30 months) and unfavorable clinical outcome, suggesting that contemporary measurement of both biomarkers than CA125 only could strengthen prognostic power of serum CA125 in predicting PFS of advanced HGSOC women. Plasma PD-L1, PD-1, BTN3A1, pan-sBTN3As, BTN2A1, or BTLA levels could be helpful biomarkers to increase prognostic value of CA125.

598P Can circulating PD-L1 levels, age at diagnosis and peritoneal carcinomatosis act as survival predictors in patients with advanced high-grade serous ovarian cancer?

High-grade serous ovarian cancer (HGSOC) is the most frequent subtype of epithelial ovarian cancer (OC) with the greater immunogenic potential due to the abundance of tumor-infiltrating immune cells which modulate the anticancer immune response. Cancer cells may evade immune surveillance, by activating immunomodulatory proteins such as programmed death protein (PD-1) and its ligand PD-L1, butyrophilin sub-family 3A/CD277 receptors (BTN3A), butyrophilin sub-family 2 member A1 (BTN2A1), and the B and T lymphocyte attenuator (BTLA). Our study aimed to assess whether circulating levels of different immunoregulatory proteins could be helpful for predicting survival of advanced HGSOC patients. The plasma PD-L1, PD-1, BTN3A1, pan-BTN3As, BTN2A1 and BTLA concentrations were analyzed in 100 advanced HGSOC women prior surgery and starting therapy, using specific ELISA tests not yet commercially available. This investigation allowed, for each tested circulating biomarker, to discriminate advanced HGSOC patients based on long (≥30 months) versus short Progression-free Survival (PFS <30 months). Through specific cut-offs obtained by ROC analysis, we showed that high baseline concentrations of PD-L1 (>0.42 ng/mL), PD-1 (>2.48 ng/mL), BTN3A1 (>4.75 ng/mL), pan-BTN3As (>13.06 ng/mL), BTN2A1 (>5.59 ng/mL) and BTLA (>2.78 ng/mL) were associated with unfavorable prognosis and median PFS from 6 to 16 months shorter. Additionally, age at diagnosis >60 years, BMI>25 or peritoneal carcinomatosis were correlated with a lower PFS (<30 months). Finally, a multivariate analysis highlighted that plasma levels of PD-L1≤0.42 ng/mL (HR: 2.23; 95% CI: 1.34 to 3.73; p=0.002), age at diagnosis ≤60 years (HR: 1.70; 95% CI: 1.07 to 2.70; p=0.024) and absence of peritoneal carcinomatosis (HR: 1.87; 95% CI: 1.23 to 2.85; p=0.003) were significant prognostic factors for a longer PFS in advanced HGSOC women. Assessing circulating PD-L1, PD-1, BTN3A1, pan-sBTN3As, BTN2A1 and BTLA levels could facilitate the identification of high-risk patients with unfavorable disease outcomes, suggesting their potential use as prognostic biomarkers.