Search Results (60)

B and T lymphocyte attenuator (BTLA) is a unique co-inhibitory receptor of the CD28 immunoglobulin superfamily that exhibits dual regulatory functions in immune activation and tolerance. Unlike PD-1 or CTLA-4, BTLA interacts bidirectionally with its ligand HVEM, forming a complex signaling network that shapes immune homeostasis within the tumor microenvironment. Dysregulated BTLA expression has been associated with tumor immune evasion and poor prognosis in several cancers. Owing to its distinctive molecular features and multifaceted immunoregulatory roles, BTLA represents an emerging therapeutic target, particularly in tumors unresponsive to conventional immune checkpoint inhibitors. This review provides a comprehensive overview of BTLA’s structure, signaling mechanisms, and functional implications in tumor immunity and discusses current advances and challenges in BTLA-targeted therapy. Finally, we outline future perspectives on leveraging BTLA modulation to enhance cancer immunotherapy outcomes. Full article

Belimumab, a fully humanized B cell-activating factor (BAFF)-targeting monoclonal antibody, inhibits autoreactive B cell survival and improves systemic lupus erythematosus (SLE) clinical outcomes. However, its administration criteria remain unclear. To establish a basis for defining these criteria, we characterized the immune cell subpopulation alterations post-belimumab treatment and elucidated the underlying mechanisms. We hypothesized that belimumab modulates specific cell subsets and investigated the post-therapy changes. Flow cytometry and correlation analysis revealed that the frequency of B- and T-lymphocyte attenuator (BTLA)^high memory B cells in peripheral blood and clinical improvement after belimumab treatment. Western blotting analysis of healthy control B cells revealed that BTLA engagement suppressed Bruton tyrosine kinase and phospholipase C-gamma 2 phosphorylation, which was enhanced by B cell and BAFF receptor co-stimulation. BTLA-expressing memory B cells, which positively correlate with disease improvement, possibly contributed to SLE improvement via BTLA-mediated signaling that attenuated B cell- and BAFF receptor-induced intracellular pathways. To validate these findings, we plan to further assess the effects of belimumab on BTLA expression and B cell signaling pathways in treatment-naive patients with SLE by western blotting. Collectively, our results provide a novel foundation for establish appropriate belimumab administration criteria. Full article

Objective: T cell exhaustion is a major mechanism of immune evasion in cancer, characterized by the sustained expression of multiple inhibitory receptors. This study aimed to evaluate the expression of immune checkpoints in peripheral and tumor-infiltrating CD8⁺ T cells from cervical cancer patients. Methods: We enrolled 104 participants: 37 treatment-naïve patients, 36 treated patients, and 31 age-matched healthy donors. Peripheral blood mononuclear cells (PBMCs) were isolated from all participants. Ten cervical biopsies were collected for tumor-infiltrating lymphocyte (TIL) isolation and paraffin fixation. Immune checkpoint expression was analyzed by multiparametric flow cytometry and immunohistochemistry. Results: In peripheral CD8⁺ T cells, we found a significant upregulation of exhaustion-associated markers PD-1, TIGIT, Tim-3, and LAG-3. In the tumor infiltrating lymphocytes, these same molecules, with the addition of NKG2A, were notably upregulated further. While BTLA and NKG2A showed no systemic changes, NKG2A increased in TILs and BTLA decreased in TILs. The co-expression of PD-1 with TIGIT, Tim-3, LAG-3, and NKG2A was notably enriched between 2- and 6-fold in TILs compared with patient PBMCs. The tumor microenvironment was highly immunosuppressive, characterized by enrichment with PD-1, PD-L1, and TIGIT; TIGIT was notably upregulated in locally advanced versus early-stage tumors. Conclusions: Our findings highlight the strongly immunosuppressive environment of cervical tumors in treatment-naïve patients and the presence of elevated inhibitory checkpoint expression in peripheral blood of both pre- and post-treatment patients. These results underscore the importance of investigating immune regulation within the tumor site itself and suggest that immune checkpoint co-expression may serve as a biomarker of T cell exhaustion and therapeutic resistance. Understanding how treatment alters these pathways could guide rational combination immunotherapies to restore CD8⁺ T cell function in cervical cancer. Full article

The oral cavity contains a diverse group of bacteria in the saliva, as well as structured aggregates of bacterial cells on the mucosal surfaces. Oral microbiota (OM) dysbiosis not only induces local inflammation, it can also trigger systemic inflammation leading to metabolic diseases and neuropsychiatric diseases (NPDs). While primary evidence indicates that oral microbiota dysbiosis induces gut microbiota aberrations, which exacerbate inflammation associated with metabolic diseases (obesity, dyslipidemia, diabetes, nonalcoholic fatty liver disease (NAFLD), and insulin resistance), other studies revealed the contribution of the oral microbiota–brain axis in the pathogenesis of NPDs. GM dysbiosis and inflammation also induce epigenetic alterations in cytokine genes, such as IL-1β, IL-6, TNF-α, NF-kB, BTLA, IL-18R1, TGF-β, P13k/Akt1, Ctnnb1, and Hsp90aa1, as well as DNMTs, HDACs, and DAT1 associated with the development and progression of metabolic disorders and/or NPDs. Therefore, the epigenome could serve as a target for preventive or therapeutic interventions. Here, we (i) review emerging evidence of the potential impact of OM dysbiosis in the pathogenesis of metabolic diseases and NPDs, (ii) highlight the relationship between OM-induced inflammation and epigenetic alterations driving NPDs pathogenesis and interlinked metabolic aberrations, (iii) discuss therapeutic approaches capable of treating metabolic diseases and NPDs through reshaping the microbiota and its epigenetic metabolites, and hence mitigating epigenetic aberrations linked to metabolic diseases and NPDs. Finally, we outline challenges and current research gaps related to investigating the relationship between microbiota, epigenetic aberrations, and metabolic abnormalities associated with NPDs. Full article

Given that we have demonstrated that miR-155-5p is increased in CLL PBMCs and that its reduction with inhibitory siRNA partially restores the immune checkpoint BTLA protein level in CLL B cells, risk stratification for using anti-miR-155-based immunotherapy in CLL seems reasonable, particularly with its potential impact on T cells. Therefore, we aimed to assess the role of miR-155-5p in the epigenetic modification of BTLA levels in CLL T cells, especially since we observed that BTLA expression unfavorably promotes increased proliferative activity and IL-4 secretion in T cells, thus suggesting BTLA malfunction in the CLL T cell subset. Transfection of PBMCs with an inhibitor of miR-155-5p (INH) led to about a ten-fold down-regulation of miR-155-5p levels compared to control siRNA (NC) both in CLL patients and healthy individuals (HC), as assessed by RT-qPCR. Additionally, we did not find any significant differences in BTLA protein expression in T cells after silencing miR-155-5p in either examined group. We demonstrated for the first time that immunotherapy approaches based on systemic administration of anti-miR-155-5p therapeutics would be a favorable strategy in CLL, since they do not affect BTLA expression in T cell populations and could benefit CLL patients with impaired BTLA levels on CLL cells. Full article

Background: Celiac disease (CD) is a gluten-sensitive immune-related enteropathy of the small intestine characterized by villus atrophy, crypt hyperplasia, and increased intraepithelial lymphocytes (IELs). Objectives: To characterize the phenotype of IELs and immune cells of the lamina propria of small intestine control using immuno-oncology and immune-phenotype markers and test the most relevant marker, an immune checkpoint co-inhibitory receptor, leukocyte-associated immunoglobulin-like receptor 1 (LAIR1), in CD. Methods: Immunohistochemical analysis of CD3 (CD3E), CD4, CD8, CD103 (ITGAE), Granzyme B (GZMB), TCR beta (β), TCR delta (δ), CD56 (NCAM), CD16 (FCGR3A), LAIR1 (CD305), PD-L1 (CD274), PD1 (CD279), BTLA (CD272), TOX2, HVEM (TNFRSF14), CD163, HLA-DP-DQ-DR, IL4I1, and FOXP3 was performed using histological analysis. Gene expression analysis was performed using an independent dataset to expand and confirm the findings. Results: IELs exhibited a cytotoxic T-cell phenotype and were CD3+, CD8+, CD103+, TCR beta+, and LAIR1+. The lamina propria (LP) was abundant in CD163+, HLA-DP-DQ-DR+, BTLA+, PD-L1+, CD103+, CD56+, and LAIR1+ cells corresponding to macrophages and T- and B-lymphocytes. In CD, IELs and part of the inflammatory cells of the lamina propria cells were LAIR1+. CD was characterized by higher quantity of LAIR1+ IELs and LP immune cells than the small intestine control (p = 0.004). Higher intestinal lesions evaluated by Marsh scoring were correlated with higher LAIR1 (p < 0.001). Gene expression analysis confirmed the overexpression of the LAIR1 pathway in CD and highlighted BTLA. At the protein level, BTLA overexpression was confirmed in CD. Finally, as a proof-of-concept AI analysis, a convolutional neural network classified LAIR1-stained image patches between the three diagnoses of small intestine control, CD, and reactive tonsils with high accuracy (99.6%). Conclusions: IELs exhibit a cytotoxic T-cell phenotype and were found to be CD3+, CD8+, CD103+, TCR beta+, and LAIR1+ in the small intestine control. Increased numbers of LAIR1+ IELs and lamina propria immune cells characterize CD. Full article

Introduction: The analysis of exhaustion marker expression, like immune checkpoint molecules (ICMs) on tumor-infiltrating lymphocytes as well as peripheral immune cells of patients with head and neck squamous cell carcinoma (HNSCC), is of high interest since it reveals information about the patient’s immune status and the effectiveness of immune modulation. However, data regarding age-dependent expression are lacking. Here, we demonstrate an increase in most ICMs associated with age and disease, suggesting immune checkpoint modulation as an evidence-based option for the treatment of aged HNSCC patients. Material and Methods: Peripheral blood mononuclear cells (PBMCs) (healthy: n = 30 with an age range from 21 to 84 years/HNSCC: n = 37 with an age range from 37 to 94 years) were analyzed via flow cytometry following (density gradient separation) standard protocol. Flow cytometry was performed using CD4 and CD8 as backbone markers as well as co-stimulatory molecules like CD137, OX40, GITR, and CD27 or ICM like PD-1, CTLA4, BTLA, LAG3, or TIM3 using a Gallios flow cytometer (Beckman Coulter, Brea, CA, USA). Results: We found a statistically significant decreased ICM expression on the PBMCs of healthy donors with increasing age. However, the expression of ICMs in HNSCC was significantly increased (PD1 on CD4⁺ T cells: p = 0.001), while we found a decreased co-stimulatory molecule expression (e.g., CD27 on CD4⁺ T cells and CD39⁺ T cells: p = 0.003 and p = 0.009, respectively). Immune cells of HPV^neg HNSCC have a significant age-dependent decrease in CD27 expression on CD8⁺, CD4⁺, and CD39⁺ T cells (p = 0.0426, p = 0.0078, and p = 0.0078, respectively). Conclusions: This study sheds light on the changing co-stimulatory molecule/ICM expression regarding the patient’s age and reveals an increase in most immune checkpoint molecules for HNSCC patients according to their age. This new evidence is valuable in ensuring individualized therapeutic approaches in the increasingly relevant field of checkpoint inhibition, even in old age. Full article

Background/Objectives: Immune checkpoint inhibitors (ICIs) do not provide promising benefits to patients with advanced epithelial ovarian cancer (EOC). This study analyzed preoperative peripheral blood mononuclear cells (PBMCs) from these patients to evaluate the prognostic and therapeutic checkpoints. Methods: Preoperative PBMCs of 69 advanced EOC cases were collected to analyze the correlation between IC-expressing immune cells and survivals of patients. Co-expression of various ICs on the T lymphocytes from these patients was examined. Activation potential of programmed cell death 1 (PD-1)⁺herpes virus entry mediator (HVEM)⁺ T cells in PBMCs from the healthy donors and tumoricidal abilities of PMBCs treated with various ICIs were evaluated in vitro. Impact of respective ICIs on activation of T cells in PMBCs was investigated. Results: Percentages of PD-1⁺ CD4⁺ and CD8⁺ T cells in the PBMCs of patients could positively correlate with disease-free or overall survival. HVEM was highly co-expressed on these T lymphocytes. Prediction potential for overall survival of patients by the subpopulation of PD-1⁺ CD4⁺ or CD8⁺ T cells was higher than that by other parameters. The PD-1⁺HVEM⁺ CD4+ and CD8⁺ T cells showed characteristics of activated phenotype under activation signals. PBMCs receiving anti-B and T lymphocyte attenuator (BTLA) plus anti-cytotoxic T lymphocyte antigen 4 (CTLA-4) or anti-PD-1 Ab had potent tumor-killing ability. Anti-BTLA Ab can drive T cells in the PBMCs toward an effector status. Conclusions: Percentages of PD-1⁺ T cells in the PBMCs could predict survival of EOC patients. Targeting HVEM-BTLA axis may be considered for ICI treatment of EOCs. Full article

Human cytomegalovirus (HCMV) establishes lifelong latency in the host, with the bone marrow (BM) CD34+ cells serving as a key reservoir. To investigate tissue-specific immune responses to CMV, we analysed paired peripheral blood mononuclear cells (PBMCs) and bone marrow mononuclear cells (BMMNCs) from HCMV-seropositive donors using multiparametric flow cytometry and cytokine FluroSpot assays. We assessed immune cell composition, memory T cell subsets, cytokine production, cytotoxic potential, activation marker expression, and checkpoint inhibitory receptor (CIR) profiles, both ex vivo and following stimulation with lytic and latent HCMV antigens. BMMNCs were enriched in CD34+ progenitor cells and exhibited distinct T cell memory subset distributions. HCMV-specific responses were compartmentalised: IFN-γ responses predominated in PBMCs following lytic antigen stimulation, while IL-10 and TNF-α responses were more prominent in BMMNCs, particularly in response to latent antigens. US28-specific T cells in the BM showed elevated expression of CD39, PD-1, BTLA, CTLA-4, ICOS, and LAG-3 on CD4+ T cells and increased expression of PD-1, CD39, BTLA, TIGIT, LAG-3, and ICOS on CD8+ T cell populations, suggesting a more immunoregulatory phenotype. These findings highlight functional and phenotypic differences in HCMV-specific T cell responses between blood and bone marrow, underscoring the role of the BM niche in shaping antiviral immunity and maintaining viral latency. Full article

Background: Currently, much attention is focused on the interactions between the leukemic and psoriatic cells showing immunosuppressive activity within the microenvironment. Methods: Our study assessed a collective mRNA expression pattern of crucial immuno-regulatory genes: BTLA, CD160, SPN, TIM-3, VISTA, TIGIT, by qRT-PCR, and performed a comparison in two different diseases, chronic lymphocytic leukemia (CLL) and psoriasis (Ps), referring to clinical characteristics. Results: In Ps, all the studied gene expressions, except TIM-3, were higher than in HVs and all the studied gene expressions, except VISTA, were lower than in CLL. However, the expression of TIM-3, a checkpoint inhibitor, was higher in 0 stage of CLL and was lower in advanced stages of the disease, suggesting its possible diagnostic value. Expression of VISTA was higher in Ps than in HVs, as well as in CLL. It is noteworthy that BTLA, CD160 and SPN were overexpressed in CLL and Ps compared to HVs, suggesting its involvement in immune suppression in both diseases. Conclusions: Significant correlations between gene expressions of SPN and BTLA, SPN and TIGIT, CD160 and TIM-3, were observed, indicating a potential shared regulatory mechanism for immune responses which suggests their bidirectional regulatory role on the functioning of immune system cells, depending on the context of inflammatory or neoplastic conditions. Full article

Checkpoint inhibitors are a modern therapeutic approach for treating various types of cancer, metabolic diseases, and chronic infections. The main goal of this therapy is to specifically unlock the immune system, allowing it to recognize and eliminate cancer cells or pathogens, primarily through the activation of T lymphocytes. Monoclonal antibodies used in the treatment of various cancers, such as pembrolizumab (Keytruda), nivolumab (Opdivo), and ipilimumab (Yervoy), carry several limitations, primarily due to their large molecular size. The main challenges include limited tissue penetration, long half-life in the body, and the risk of autoimmune responses. Compared to antibodies, small-molecule and peptide inhibitors offer significant advantages related to their molecular structure. These drugs demonstrate a better ability to penetrate hard-to-reach areas, such as the tumor microenvironments, can be administered orally, and often show lower immunogenicity. A new generation of drugs is PROTACs, which combine the ability to direct proteins to degradation with the action of checkpoint inhibitors, contributing to the elimination of proteins responsible for suppressing the immune response. This publication describes small-molecule inhibitors, peptide inhibitors, and PROTAC molecules targeting negative immune checkpoints—CTLA-4, PD-1, VISTA, TIM-3, BTLA-4, LAG-3, and TIGIT. Full article

Introduction: Prostate cancer has been generally resistant to immunotherapy approaches. Radiation can be immunostimulatory, but the extent to which standard prostate cancer treatments induce immune activation has not been well described. The bone-targeted radiopharmaceutical Radium223 (Ra223) has been proposed to enrich immune function, but clinical studies have not fully delineated whether this is true, or by what mechanisms. Enzalutamide has been shown to increase PD-L1 expression on dendritic cells, which could impact immune activation, though the extent to which this is associated with other evidence of immune activation remains uncertain, and combination strategies remain of interest. We performed a randomized phase II trial to evaluate whether Radium223 (Ra223) added to enzalutamide would induce greater immune activation and clinical responses compared to enzalutamide alone in men with metastatic castration-resistant prostate cancer (mCRPC). Methods: Eligible patients were randomized 2:1 to Arm A (enzalutamide 160 mg PO daily + Ra223 55 kBq/kg IV q4 weeks × 6 doses) or Arm B (enzalutamide 160 mg PO daily). Blood was collected at treatment start and during treatment to measure soluble immune checkpoint biomarkers (BTLA, TIM3, HVEM, GITR, LAG3, PD-1, CTLA-4, PD-L1, PD-L2, ICOS). Immunophenotyping by mass cytometry time of flight (CyTOF) was performed to measure peripheral blood mononuclear cell populations before and after treatment. CyTOF was used to determine changes in circulating immune cell population subsets before and after treatment. Biopsies were performed of an active bone metastatic lesion prior to study treatment and after at least 3 months. IHC was subsequently performed to examine changes in immune cell population subsets before and after treatment, and changes in pSTAT3 levels. Results: In total, 30 patients were enrolled, with median age 68. The median duration of follow up was 36 months. PSA responses, PFS, and OS were not significantly different between the two arms; however, the study was not powered for clinical endpoints. Peripheral blood and bone biopsy specimens were analyzed for immune correlatives. Soluble receptor concentrations showed significantly increased expression of PDL-2 in the combination arm, but this was not seen on CyTOF. Otherwise, there were no significant differences in markers of immune activation/exhaustion or immune cell population subsets in the combination arm and enzalutamide monotherapy arm. IHC also did not show a significant difference in immune cell population subsets in bone biopsy specimens before and after treatment in both arms. However, treatment with the combination arm did show significantly increased levels of pSTAT3 (p = 0.04), which was not seen in the enzalutamide monotherapy arm. Conclusions: Our study showed an overall lack of evidence for immune activation or cytokine induction with the combination, which does not make a strong case for combinatorial immunotherapy approaches. However, the combination did induce higher levels of pSTAT3, which has been implicated in radio-resistance. Therefore, the addition of a STAT3 inhibitor to the combination may be of interest to improve efficacy. Full article

Pancreatic ductal adenocarcinoma (PDAC) is aggressive, with a 5-year survival rate of only 12.8%, and its increasing incidence in Western countries highlights the urgent need for better early-stage detection and treatment methods. Early diagnosis significantly improves the chances of survival, but non-specific symptoms and undetectable precursor lesions pose a major challenge. To date, there are no reliable screening tools to detect PDAC at an early stage. Herpesvirus entry mediator (HVEM) has already been proposed as a prognostic marker in numerous cancer types. Therefore, we investigated the role of HVEM in PDAC. Flow cytometry was used to analyze HVEM expression in immune cells and its inhibitory receptors (CD160 and BTLA) on T-cells, as well as its subsets in the peripheral blood of 57 diagnosed PDAC patients and 17 clinical controls. In addition, survival analyses were performed within the PDAC cohort, changes in HVEM expression were analyzed in relation to clinicopathological parameters, and a correlation analysis between HVEM expression and cytokine levels of IL-6 and IL-10 was conducted. Furthermore, HVEM expression on monocytes and their subsets was evaluated as a potential prognostic marker and compared with the prognostic utility of CA19-9. We found that HVEM expression is significantly elevated on immune cells, particularly on monocytes (p < 0.0001) and their subsets, in PDAC patients, and is associated with reduced survival (p = 0.0067) and clinicopathological features such as perineural, lymphovascular, and vascular invasion. Moreover, HVEM-expressing monocytes demonstrated superior predictive value compared to CA19-9, highlighting their potential as part of a combined screening tool for PDAC. In conclusion, HVEM on monocytes could serve as a novel prognostic marker for PDAC. Full article

Background: Despite significant strides in anti-melanoma therapies, resistance and recurrence remain major challenges. A deeper understanding of the underlying biology of these challenges is necessary for developing more effective treatment paradigms. Methods: Melanoma single-cell data were retrieved from the Broad Single Cell Portal (SCP11). High-dimensional weighted gene co-expression network analysis (hdWGCNA), CellChat, and ligand-receptor relative crosstalk (RC) scoring were employed to evaluate intercellular and intracellular signaling. The prognostic value of key regulatory genes was assessed via Kaplan-Meier (KM) survival analysis using the ‘SKCM-TCGA’ dataset. Results: Twenty-seven (27) gene co-expression modules were identified via hdWGCNA. Notable findings include NRAS Q61L melanomas being enriched for modules involving C19orf10 and ARF4, while BRAF V600E melanomas were enriched for modules involving ALAS1 and MYO1B. Additionally, CellChat analysis highlighted several dominant signaling pathways, namely MHC-II, CD99, and Collagen-receptor signaling, with numerous significant ligand-receptor interactions from melanocytes, including CD99-CD99 communications with cancer-associated fibroblasts, endothelial cells, NK cells, and T-cells. KM analysis revealed that higher expression of SELL, BTLA, IL2RG, PDGFA, CLDN11, ITGB3, and SPN improved overall survival, while higher FGF5 expression correlated with worse survival. Protein-protein interaction network analysis further indicated significant interconnectivity among the identified prognostic genes. Conclusions: Overall, these insights underscore critical immune interactions and potential therapeutic targets to combat melanoma resistance, paving the way for more personalized and effective treatment strategies. Full article

The dialogue between T and B cells can be regulated by different mechanisms, such as co-inhibitory receptors, which therefore play a crucial role in preventing autoimmune diseases such as systemic lupus erythematosus (SLE). B and T lymphocyte attenuator (BTLA) is a co-inhibitory receptor expressed on many myeloid and lymphoid cells. Although peripheral B cells express a very high amount of BTLA, previous works in the context of autoimmunity mainly focused on T cells, and whether BTLA expression on B cells plays a role in the lupus pathogenesis is still unclear. In the present study, we examine the expression of BTLA, as well as its ligand HVEM (Herpesvirus Entry Mediator), on various B cell subsets in lupus patients compared to healthy controls (HCs). We evidenced the existence of double-negative (DN; IgD⁻CD27⁻) memory B cells expressing very low levels of BTLA, which are enhanced in active lupus patients. An in-depth analysis revealed that these BTLA^low DN cells mainly correspond to the newly reported DN3 B cell subset, originally described in the context of SARS-CoV2 infection. These cells display an activated and antibody-secreting cell phenotype, and we propose that their low BTLA expression may favor their expansion and rapid differentiation into plasmablasts in lupus patients. Full article