Search Results (3,699)

Background Plasma membrane proteins (PMPs) play key roles in cell signalling, adhesion, and trafficking, and are attractive therapeutic targets in cancer due to their surface accessibility. However, their typically low abundance limits detection by conventional proteomic approaches. Methods: To improve PMP detection, we employed a surface proteomics workflow combining cell surface biotinylation and affinity purification prior to LC-MS/MS analysis in cervical (SiHa) and bladder (UMUC3) cancer cell lines cultured under normoxic (21% O₂) or hypoxic (0.1% O₂) conditions. Results: In SiHa cells, 43 hypoxia-upregulated proteins were identified exclusively in the biotin-enriched fraction, including ITGB2, ITGA7, AXL, MET, JAG2, and CAV1/CAV2. In UMUC3 cells, 32 unique upregulated PMPs were detected, including CD55, ADGRB1, SLC9A1, NECTIN3, and ACTG1. These proteins were not observed in corresponding whole-cell lysates and are associated with extracellular matrix remodelling, immune modulation, and ion transport. Biotinylation enhanced the detection of membrane-associated pathways such as ECM organisation, integrin signalling, and PI3K–Akt activation. Protein–protein interaction analysis revealed links between membrane receptors and intracellular stress regulators, including mitochondrial proteins. Conclusions: These findings demonstrate that surface biotinylation improves the sensitivity and selectivity of plasma membrane proteomics under hypoxia, revealing hypoxia-responsive proteins and pathways not captured by standard whole-cell analysis. Full article

Although PD-1/PD-L1 inhibitors have transformed cancer immunotherapy, a substantial proportion of patients derive no clinical benefit due to resistance driven by the tumour microenvironment (TME). Transforming growth factor-β (TGF-β) is a key immunosuppressive cytokine implicated in this resistance. Several bifunctional antibodies that co-target PD-1 and TGF-β signalling have entered clinical trials and shown encouraging efficacy, but the mechanistic basis of their synergy is not fully understood. Here, we engineered 015s, a bifunctional fusion antibody that simultaneously targets murine PD-1 and TGF-β and evaluated its antitumour efficacy and mechanistic impact in pre-clinical models. Antibody 015s exhibited high affinity, dual target binding, and the effective inhibition of PD-1 and TGF-β signalling. In vivo, 015s significantly suppressed tumour growth compared with anti-mPD-1 or TGF-β receptor II (TGF-βRII) monotherapy. When combined with the CD24-targeted ADC, 015s produced even greater antitumour activity and achieved complete tumour regression. Mechanistic studies demonstrated that 015s significantly reduced tumour cell migration and invasion, reversed epithelial–mesenchymal transition (EMT), decreased microvascular density, and attenuated collagen deposition within the TME. Antibody 015s also decreased bioactive TGF-β1 and increased intratumoural IFN-γ, creating a more immunostimulatory milieu. These findings support further development of PD-1/TGF-β bifunctional antibodies for cancers with high TGF-β activity or limited response to immune checkpoint blockade. Full article

The biological effects of nanoparticles are closely related to their intracellular content and location, both of which are influenced by various factors. This study investigates the effects of surface charge on the uptake, intracellular distribution, and exocytosis of CdSe/ZnS quantum dots (QDs) in Raw264.7 macrophages. Negatively charged 3-mercaptopropanoic acid functionalized QDs (QDs-MPA) show higher cellular uptake than positively charged 2-mercaptoethylamine functionalized QDs (QDs-MEA), and serum enhances the uptake of both types of QDs via protein corona-mediated receptor endocytosis. QDs-MEA primarily enter the cells through clathrin/caveolae-mediated pathways and predominantly accumulate in lysosomes, while QDs-MPA are mainly internalized through clathrin-mediated endocytosis and localize to both lysosomes and mitochondria. Exocytosis of QDs-MPA is faster and more efficient than that of QDs-MEA, though both exhibit limited excretion. In addition to endocytosis and exocytosis, cell division influences intracellular QD content over time. These results reveal the charge-dependent interactions between QDs and macrophages, providing a basis for designing biocompatible nanomaterials. Full article

Murine microglia exhibit rapid self-renewal upon removal from the postnatal brain. However, the signaling pathways that regulate microglial repopulation remain largely unclear. To address this knowledge gap, we depleted microglia from mixed glial cultures using anti-CD11b magnetic particles and cultured them for 4 weeks to monitor their repopulation ability in vitro. Flow cytometry and immunocytochemistry revealed that anti-CD11b bead treatment effectively eliminated >95% of microglia in mixed glial cultures. Following removal, the number of CX3CR1-positive microglia gradually increased; when a specific threshold was reached, repopulation ceased without any discernable rise in cell death. Cell cycle and 5-ethynyl-2′-deoxyuridine incorporation assays suggested the active proliferation of repopulating microglia at d7. Time-lapse imaging demonstrated post-removal division of microglia. Colony-stimulating factor 1 receptor-phosphoinositide 3-kinase-protein kinase B signaling was identified as crucial for microglial repopulation, as pharmacological inhibition or neutralization of the pathway significantly abrogated repopulation. Transwell cocultures revealed that resident microglia competitively inhibited microglial proliferation probably through contact inhibition. This in vitro microglial removal system provides valuable insights into the mechanisms underlying microglial proliferation. Full article

Systemic lupus erythematosus (SLE) is a severe autoimmune disease characterized by autoantibody production and multi-organ involvement. Anifrolumab, a monoclonal antibody targeting the type I interferon (IFN) receptor, has been approved for the treatment of SLE. Our aim was to investigate the long-term effects of inhibited type I IFN signaling on circulating follicular helper T subsets (T_FH), follicular regulatory T cells (T_FR), and B lymphocyte subpopulations, reflecting the ongoing germinal center reactions in SLE patients. Peripheral blood samples were obtained from ten SLE patients before the initiation of anifrolumab treatment, and at months 6 and 12 of the intervention period. Flow cytometry analysis was performed to assess the frequencies of circulating T_FH cell subsets, T_FR cells, and certain B cell subpopulations. Serological parameters, including autoantibody levels and complement components, were determined as part of the routine diagnostic evaluation. We observed a significant and sustained reduction in the percentage of activated circulating T_FH cells. Notably, the frequency of CXCR3⁻CCR6⁺ T_FH17 cells decreased, whereas the proportion of CXCR3⁺CCR6⁻ T_FH1 cells increased significantly. Furthermore, the proportion of the IgD⁻CD27⁻ double-negative B lymphocytes was also significantly reduced. These findings suggest that anifrolumab therapy attenuates T_FH cell activation, which may contribute to its clinical efficacy by modulating germinal center responses in SLE. Full article

Background: Soft tissue sarcomas (STSs) are a rare and heterogeneous group of mesenchymal tumors with limited response to current therapies, particularly in advanced stages. STS tumors were traditionally considered “cold” tumors, characterized by limited immune infiltration and low immunogenicity. However, emerging evidence is challenging this perception, highlighting a potentially critical role for the immune system in STS biology. Objective: Building on our previous findings suggesting impaired natural killer (NK) cell activity in STS patients, we aimed to perform an in-depth characterization of peripheral NK cells in STS. Methods: Peripheral blood samples from STS patients and sex- and age-matched healthy donors were analyzed to assess NK cell degranulation, IFNγ production, and receptor repertoire. Results: Functional assays revealed a notable reduction in both degranulation and IFNγ production in NK cells from STS patients. STS patients also exhibited dysregulated expression of activating and inhibitory NK cell receptors. Principal component analysis (PCA) identified CD27 and NKp44 as critical markers for distinguishing STS patients from healthy donors. Increased CD27 expression represents a shift towards a more regulatory NK cell phenotype, and we found that CD27 expression was negatively correlated with NK cell degranulation and IFNγ production. ROC curve analysis demonstrated strong potential to distinguish between the groups for both CD27 (AUC = 0.85) and NKp44 (AUC = 0.94). Conclusion: In conclusion, STS patients exhibited impaired NK cell function, altered receptor repertoire, and a shift towards a less cytotoxic and more regulatory phenotype. Full article

Neutrophils play a key role in autoimmune diseases like rheumatoid arthritis, contributing to tissue damage through rapid recruitment and activation. In this study, we investigated the regulatory properties of two receptor-like tyrosine phosphatases (RPTPs), CD45 and CD148, in inflammatory arthritis. Using an in vivo mouse model of K/BxN serum transfer-induced arthritis, we found that CD45 and CD148 feature distinct regulatory properties during inflammatory arthritis. CD45 is required for neutrophil infiltration, cytokine release, and reactive oxygen species production, whereas CD148 deficiency leads to a delayed onset of arthritis but unaltered overall neutrophil infiltration and reduced ROS production. Furthermore, we could demonstrate that activation of Src family kinases in neutrophils is differentially regulated by CD45 and CD148 in a stimulus-dependent manner. Summarizing, our results suggest that CD45 is positively involved, while CD148 is positively and negatively involved in neutrophil recruitment and function during inflammatory arthritis. Full article

FMC63-CAR T cell therapy targeting CD19 protein on malignant B-cells is effective in patients with relapsed or refractory diffuse large B-cell lymphoma (r/r DLBCL), with complete response rates of 43–54%. Common germline variants of the immune-checkpoint regulator CTLA-4 may elicit different responses to CAR-T cell therapy. The CTLA4 gene single-nucleotide polymorphism rs231775 coding threonine or alanine at amino acid position 17 of the CTLA-4 protein was prevalent in 55% of the studied DLBCL patients. In a retrospective comparative analysis of clinical outcome, there were significant differences in CTLA4 A17hom vs. T17Ahet and T17hom carriers with four-year progression-free survival at 77%, 59%, and 30% (p = 0.019), four-year overall survival was 79%, 41%, and 33% (p = 0.049), the relapse rates were 20%, 37%, and 56% (p = 0.025), and the death rates 20%, 54%, and 52% (p = 0.049). Conclusions: CTLA4 rs231775 polymorphism may impact the treatment outcome in FMC63-anti-CD19 CAR-T cell therapy, with an association of the CTLA4 minor allele A17 to favorable treatment outcome. Full article

T-cells constitute an essential component of the adaptive immune response, mount a protective response against foreign pathogens and are important regulators of anti-tumor immunotherapy. In this context, the activation of T-cells and chimeric antigen receptor (CAR)-expressing T-cells is orchestrated by various signaling pathways, involving the initiation of a protein tyrosine phosphorylation cascade. For T-cells, this involves initiation of the phosphorylation cascade via src-related protein-tyrosine kinase p56^lck, which we show to associate with the co-receptors CD4 and CD8 for the induction of a phosphorylation cascade needed for the activation of T-cells. Likewise, p56^lck phosphorylation of the antigen receptor immunoreceptor tyrosine-based activation motifs (ITAMs) and key CD28 tyrosine motifs ensures the functionality and the survival of CARs, while their phospho-targets are also inhibited by PD-1, a key component of the immune checkpoint blockade. This review covers historic and current elements of our knowledge of CD4/CD8–p56^lck-induced activation events and their importance to the development of CAR T-cell immunotherapies. Full article

In this review, we explore the complexities of objectively assessing the response to immunotherapy in mycosis fungoides (MF), a prevalent form of cutaneous T-cell lymphoma. The core challenge lies in distinguishing between reactive and malignant lymphocytes amidst treatment, particularly given the absence of uniform pathological biomarkers for MF. We highlight the vital role of emerging histological technologies, such as multispectral imaging and spatial transcriptomics, in offering a more profound insight into the tumor microenvironment (TME) and its dynamic response to immunomodulatory therapies. Drawing on parallels with melanoma—another immunogenic skin cancer—our review suggests that methodologies and insights from melanoma could be instrumental in refining the approach to MF. We specifically focus on the prognostic implications of various TME cell types, including CD8+ tumor-infiltrating lymphocytes, natural killer (NK) cells, and histiocytes, in predicting therapy responses. The review culminates in a discussion about adapting and evolving treatment response quantification strategies from melanoma research to the distinct context of MF, advocating for the implementation of novel techniques like high-throughput T-cell receptor gene rearrangement analysis. This exploration underscores the urgent need for continued innovation and standardization in evaluating responses to immunotherapies in MF, a field rapidly evolving with new therapeutic strategies. Full article

Cerebral malaria (CM) is the severe progression of an infection with Plasmodium falciparum, causing detrimental damage to brain tissue and is the most frequent cause of Plasmodium falciparum mortality. The critical role of brain-infiltrating CD8⁺ T cells in the pathophysiology of CM having been revealed, our investigation focuses on the role of NR2F6, an established immune checkpoint, as a candidate driver of CM pathology. We employed an experimental mouse model of CM based on Plasmodium berghei ANKA (PbA) infection to compare the relative susceptibility of Nr2f6-knock-out and wild-type C57BL6/N mice. As a remarkable result, Nr2f6 deficiency confers a significant survival benefit. In terms of mechanism, we detected less severe endotheliopathy and, hence, less damage to the blood–brain barrier (BBB), accompanied by decreased sequestered parasites and less cytotoxic T-lymphocytes within the brain, manifesting in a better disease outcome. We present evidence that NR2F6 deficiency renders mice more resistant to experimental cerebral malaria (ECM), confirming a causal and non-redundant role for NR2F6 in the progression of ECM disease. Consequently, pharmacological inhibitors of the NR2F6 pathway could be of use to bolster BBB integrity and protect against CM. Full article

Tuberous sclerosis complex (TSC) is a systemic disease caused by mutations in either the TSC1 (encoding hamartin) or TSC2 (encoding tuberin) gene, with mutations in the TSC2 gene potentially leading to more severe clinical symptoms. Neurological symptoms are a common clinical manifestation of TSC, and neuroinflammation is thought to play an important role. Glial cells are a major source of neuroinflammation, but whether microglia are involved in the activation of the NOD-like receptor protein 3 (NLRP3) inflammasome and the expression of interleukin-1β (IL-1β) in TSC patients remains unclear. We used a transcriptome sequencing dataset for bioinformatics analysis to explore the differences in the expression of microglial inflammasome-associated hub genes. TSC2 knockdown (TSC2 KD) microglia (HMC3 cell line) were generated by lentivirus, and the expression of inflammasome-associated hub genes, microglial activation, and NLRP3 inflammasome activation were verified. In addition, experiments were performed to explore the regulatory effects of rapamycin. Bioinformatics analysis identified a total of eight inflammasome-associated hub genes. By detecting GFP fluorescence, TSC2 mRNA, TSC2 protein expression, and the phosphorylation of the mammalian target of rapamycin (p-mTOR)/mTOR, we confirmed that the TSC2 KD microglia model was successfully established. Compared with the control group, the TSC2 KD group presented higher mRNA levels and fluorescence intensities of microglia AIF1 and CD68, as well as greater reactive oxygen species (ROS) production. Eight inflammasome-associated hub gene mRNA assays revealed that the expression of the NLRP3 and IL1B genes was increased. Compared with the control group, the TSC2 KD group presented increased levels of NLRP3 and Pro-IL-1β proteins in cells and Cleaved-Caspase 1 and Cleaved-IL-1β proteins in the supernatant, suggesting NLRP3 inflammasome activation. Rapamycin intervention alleviated these changes, demonstrating that the TSC2 gene regulation of microglial activation and NLRP3 inflammasome activation are correlated with mTOR phosphorylation. In conclusion, microglia are activated in TSC patients and participate in the NLRP3 inflammasome-associated neuroinflammatory response, and rapamycin treatment can alleviate these changes. Full article

Monkeypox virus (MPXV) has caused 148,892 confirmed cases and 341 deaths from 137 countries worldwide, as reported by the World Health Organization (WHO), highlighting the urgent need for effective vaccines to prevent the spread of MPXV. Traditional vaccine development is low-throughput, expensive, time consuming, and susceptible to reversion to virulence. Alternatively, a reverse vaccinology approach offers a rapid, efficient, and safer alternative for MPXV vaccine design. Here, MPXV proteins associated with viral infection were analyzed for immunogenic epitopes to design multi-epitope vaccines based on B-cell, CD4+, and CD8+ epitopes. Epitopes were selected based on allergenicity, antigenicity, and toxicity parameters. The prioritized epitopes were then combined via peptide linkers and N-terminally fused to various protein adjuvants, including PADRE, beta-defensin 3, 50S ribosomal protein L7/12, RS-09, and the cholera toxin B subunit (CTB). All vaccine constructs were computationally validated for physicochemical properties, antigenicity, allergenicity, safety, solubility, and structural stability. The three-dimensional structure of the selected construct was also predicted. Moreover, molecular docking and molecular dynamics (MD) simulations between the vaccine and the TLR-4 immune receptor demonstrated a strong and stable interaction. The vaccine construct was codon-optimized for high expression in the E. coli and was finally cloned in silico into the pET21a (+) vector. Collectively, these results could represent innovative tools for vaccine formulation against MPXV and be transformative for other infectious diseases. Full article

The effective suppression of inflammation using disease-modifying therapies is essential in the treatment of multiple sclerosis (MS). Anti-CD20 monoclonal antibodies are commonly used long-term as maintenance therapies, largely due to the lack of reliable biomarkers to guide dosing and evaluate treatment response. However, prolonged use increases the risk of infections and other immune-mediated side effects. The unique ability of brain-derived blood extracellular vesicles (EVs) to cross the blood–brain barrier and reflect the central nervous system (CNS) immune status has sparked interest in their potential as biomarkers. This study aimed to assess whether blood-derived L1CAM⁺ EVs could serve as biomarkers of treatment response to rituximab (RTX) in patients with relapsing-remitting MS (RRMS). Serum samples (n = 25) from the baseline (month 0) and after 6 months were analyzed from the RTX arm of the ongoing randomized clinical trial OVERLORD-MS (comparing anti-CD20 therapies in RRMS patients) and were compared with serum samples from healthy controls (n = 15). Baseline cerebrospinal fluid (CSF) samples from the same study cohort were also included. EVs from both serum and CSF samples were characterized, considering morphology, size, and concentration, using transmission electron microscopy (TEM) and nanoparticle tracking analysis (NTA). The immunophenotyping of EV surface receptors was performed using flow cytometry with the MACSPlex exosome kit, while label-free quantitative proteomics of EV protein cargo was conducted using a proximity extension assay (PEA). TEM confirmed the presence of EVs with the expected round morphology with a diameter of 50–150 nm. NTA showed significantly higher concentrations of L1CAM⁺ EVs (p < 0.0001) in serum total EVs and EBNA1⁺ EVs (p < 0.01) in serum L1CAM⁺ EVs at baseline (untreated) compared to in healthy controls. After six months of RTX therapy, there was a significant reduction in L1CAM⁺ EV concentration (p < 0.0001) and the downregulation of TNFRSF13B (p = 0.0004; FC = −0.49) in serum total EVs. Additionally, non-significant changes were observed in CD79B and CCL2 levels in serum L1CAM⁺ EVs at baseline compared to in controls and after six months of RTX therapy. In conclusion, L1CAM⁺ EVs in serum showed distinct immunological profiles before and after rituximab treatment, underscoring their potential as dynamic biomarkers for individualized anti-CD20 therapy in MS. Full article

Cancer remains a major cause of mortality worldwide, driven by complex molecular mechanisms that promote metastasis and resistance to therapy. Receptor for hyaluronan-mediated motility (RHAMM) has emerged as a multifunctional regulator in cancer, contributing to cell motility, invasion, proliferation, and fibrosis. In addition to being regulated by non-coding RNAs (ncRNAs), including miRNAs, lncRNAs, and circRNAs, RHAMM serves as a promising therapeutic target. Recent developments in RHAMM-targeted strategies include function-blocking peptides (e.g., NPI-110, NPI-106, and P15-1), hyaluronan (HA) oligomers, and anti-RHAMM antibodies, all shown to modulate tumor stroma and suppress tumor invasiveness. Importantly, RHAMM-targeted peptide vaccines, such as the RHAMM-R3 epitope, have demonstrated immunogenicity and anti-leukemia efficacy in both pre-clinical and early clinical studies, suggesting their potential to elicit specific CD8⁺ T-cell responses and enhance graft-versus-leukemia effects. This review summarizes the intricate roles of RHAMM in cancer progression, its modulation by ncRNAs, and the translational promise of novel RHAMM-targeting approaches, providing insights into future directions for precision cancer therapy. Full article