A. Starr et al. (Oct 2025)
Journal of Neuroimmune Pharmacology 20 1
Differential Effects of Cannabinoid Receptor 2 Agonists on HIV Replication and Inflammatory Activation in Monocyte-Derived Macrophages and Induced Pluripotent Stem Cell-Derived Microglia
Emerging evidence suggests brain-resident myeloid cells,including perivascular macrophages and microglia,provide a reservoir for HIV infection in the central nervous system (CNS),and their inflammatory activation is a proposed pathogenic mechanism in HIV-associated neurocognitive disorders (HAND). We investigated whether cannabinoid receptor 2 (CB2),an immunomodulatory receptor expressed in myeloid cells,regulates viral replication and inflammation in HIV-infected macrophages and microglia. Using the synthetic CB2-specific agonist JWH-133,we found that CB2 activation reduced HIV replication in primary human monocyte-derived macrophages (MDMs) and human induced pluripotent stem cell-derived microglia (iMg) at differing doses,corresponding to the basal expression of CNR2,which encodes CB2,and related endocannabinoid transcripts in each cell type. JWH-133 broadly reduced release of cytokines from HIV-infected MDMs but not iMg. RNA-seq revealed that CB2 agonism primarily altered interferon and integrated stress response pathways in MDMs while altering homeostatic pathways,including synapse maintenance and phagocytosis,in iMg. Further analyses in iMg revealed that NLRP3 inflammasome activation,but not priming,was reduced by CB2 activation,which did not inhibit HIV-induced nuclear factor kB activation. This study identifies key differences in CB2 response between myeloid lineage cell types and implicates CB2-specific agonists as promising candidates for the regulation of HIV-associated neuroinflammation.
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T. Frey et al. (Oct 2025)
Cell Communication and Signaling : CCS 23 2.45E+03
T cell receptor associated transmembrane adaptor 1 (TRAT1) modulates human Th17 and Treg responses via PI3-kinase and STAT dependent mechanisms
BackgroundAdaptor proteins associated with the T cell receptor (TCR) play critical roles in regulating immune responses by Translating receptor engagement into intracellular signals. T cell Receptor Associated Transmembrane Adaptor 1 (TRAT1) has been implicated in modulating TCR complex stability,but its functional role in human effector and regulatory CD4⁺ T cell subsets remains poorly understood. This study aimed to elucidate the role of TRAT1 in regulating T cell activation and differentiation,particularly in helper T cells function and regulatory T cells.MethodsPrimary human CD4⁺ T cells,including thymus-derived and induced regulatory T cells (Treg),were genetically modified by CRISPR/Cas9-mediated gene deletion or retro-/lentiviral overexpression of TRAT1. Functional assays,flow cytometry,cytokine quantification,and RNA sequencing were performed to evaluate modulation of T cell functions. Mechanistic studies included pathway inhibition using small molecules and phospho-protein analysis. The influence of TRAT1 on Treg function was further assessed in a CAR Treg context in an immune organoid model of allo-rejection.ResultsThymus-derived,TGFb-induced and FOXP3-transgenic Treg displayed reduced expression of TRAT1 compared to effector T cells,which showed pronounced up-regulation of TRAT1 following activation. In effector T cells,deletion of TRAT1 led to increased signaling through the phosphoinositide 3-kinase pathway resulting in enhanced proliferation and increased expression of activation markers. However,this was accompanied by reduced production of interleukin-17,which was linked to elevated activity of STAT6 as shown by inhibition experiments using small molecule inhibitors. Overexpression and CRISPR/Cas9-mediated knockout of TRAT1 in Treg enhanced suppression of CD4⁺ target cells via up-regulation of LAP/GARP but reduced suppression of CD8⁺ target cells,an effect confirmed in HLA-A2-specific CAR Treg in a human organoid model of allo-rejection.ConclusionsTRAT1 acts as a dual regulator of human CD4⁺ T cell function,limiting effector activation through modulation of intracellular signaling and supporting regulatory T cell-mediated suppression. These findings reveal a novel mechanism of immune regulation with potential implications for the development of cell-based immunotherapies.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12964-025-02429-z.
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M. Fernandez et al. (Sep 2025)
Frontiers in Oncology 15
Targeting RAB7 in human B lymphoma by a small molecule inhibitor arrests tumor cell growth
RAB7,encoded by RAB7A in humans and Rab7 in mice,is a small GTPase that catalyzes endosome maturation. It mediates NF-κB activation through the assembly of intracellular membrane signalosomes in stimulated normal B cells and plays a B cell-intrinsic role in the antibody response in mice. Here we show RAB7A transcripts are expressed in primary diffuse large B-cell lymphomas (DLBCLs),and that RAB7 protein expression is heightened in activated human tonsil B cells as well as in DLBCL and Burkitt lymphoma cell lines. Treating these cell lines with CID1067700,a selective small-molecule RAB7 inhibitor,results in a dose-dependent decrease in cell growth,associated with impaired proliferation and survival. CID1067700 also suppressed tumor development from Daudi cells,a Burkitt lymphoma cell line,in Foxn1nu/nu nude mice. The inhibitory effect of CID1067700 on Daudi cell growth in vitro is further enhanced by methyl-β-cyclodextrin,which disrupts plasma membrane lipid rafts,and by FX1,a BCL6 inhibitor. These findings,together with the unfavorable prognosis of DLBCL patients showing high RAB7A expression,suggest that targeting RAB7 is a promising therapeutic approach for mature B cell-derived lymphomas.
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R. A. Purcell et al. (Oct 2025)
NPJ Vaccines 10
Dysregulated inflammation in solid tumor malignancy patients shapes polyfunctional antibody responses to COVID-19 vaccination
Solid tumor malignancy (STM) patients experience increased risk of breakthrough SARS-CoV-2 infection owing to reduced COVID-19 vaccine immunogenicity. However,the underlying immunological causes of impaired neutralization remain poorly characterized. Furthermore,non-neutralizing antibody functions can contribute to reduced disease severity but remain understudied within high-risk populations. We dissected polyfunctional antibody responses in STM patients and age-matched controls who received adenoviral vector- or mRNA-based COVID-19 vaccine regimens. Elevated inflammatory biomarkers,including agalactosylated IgG,interleukin (IL)-6,IL-18,and an expanded population of CD11c−CD21− double negative 3 (DN3) B cells were observed in STM patients and were associated with impaired neutralization. In contrast,mRNA vaccination induced Fc effector functions that were comparable in patients and controls and were cross-reactive against SARS-CoV-2 variants. These data highlight the resilience of Fc functional antibodies and identify systemic inflammatory biomarkers that may underpin impaired neutralizing antibody responses,suggesting potential avenues for immunomodulation via rational vaccine design.
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C. Pastorio et al. (Oct 2025)
Signal Transduction and Targeted Therapy 10
Retinol Binding Protein 4 reactivates latent HIV-1 by triggering canonical NF-κB, JAK/STAT5 and JNK signalling
Reactivation of the latent viral reservoirs is crucial for a cure of HIV/AIDS. However,current latency reversing agents are inefficient,and the endogenous factors that have the potential to reactivate HIV in vivo remain poorly understood. To identify natural activators of latent HIV-1,we screened a comprehensive peptide/protein library derived from human hemofiltrate,representing the entire blood peptidome,using J-Lat cell lines harboring transcriptionally silent HIV-1 GFP reporter viruses. Fractions potently reactivating HIV-1 from latency contained human Retinol Binding Protein 4 (RBP4),the carrier of retinol (Vitamin A). We found that retinol-bound holo-RBP4 but not retinol-free apo-RBP4 strongly reactivates HIV-1 in a variety of latently infected T cell lines. Functional analyses indicate that this reactivation involves activation of the canonical NF-κB pathway and is strengthened by JAK/STAT5 and JNK signalling but does not require retinoic acid production. High levels of RBP4 were detected in plasma from both healthy individuals and people living with HIV-1. Physiological concentrations of RBP4 induced significant viral reactivation in latently infected cells from individuals on long-term antiretroviral therapy with undetectable viral loads. As a potent natural HIV-1 latency-reversing agent,RBP4 offers a novel approach to activating the latent reservoirs and bringing us closer to a cure. Subject terms: Preclinical research,Infectious diseases
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J. Zhou et al. (Sep 2025)
Alzheimer's Research & Therapy 17
A novel electric field approach for improving cognitive function through ameliorating cell-specific pathology in P301S tauopathy mice
Alzheimer’s disease (AD) is a devastating neurodegenerative disorder,with no effective treatment currently available. Recently,non-pharmacological therapy,especially gamma frequency stimulation has shown promising therapeutic effects in Alzheimer’s disease (AD) mouse models. Electric field (EF) is a non-invasive biophysical approach for neuronal protection. However,whether EF is beneficial in AD neuropathology remains unknown. In this study,we exposed the P301S tauopathy mouse model to EF at gamma frequency on the head. We demonstrated that EF treatment significantly improved the cognitive impairments in the P301S mice. This was accompanied by reduced tau pathologies,suppressed microglial activation,neuroinflammation and oxidative stress in the tauopathy mouse brain. Moreover,EF treatment induced cell-specific responses in neural cells,with neurons being more susceptible,followed by microglia and oligodendrocytes. EF also had favorable effects on synaptic protein in neurons,inflammatory response and complement signaling in microglia,and myelination in oligodendrocytes. This study provides strong evidence that EF at gamma frequency may have great potential to be a novel therapeutic intervention for P301S by attenuating neuropathology and offering neuroprotection.Supplementary InformationThe online version contains supplementary material available at 10.1186/s13195-025-01859-8.
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E. Le et al. (Sep 2025)
Mobile DNA 16 9
Type I interferons increase expression of endogenous retrovirus K102 and envelope protein in myeloid cells from patients with autoimmune disease
Autoantibodies against envelope (Env) protein encoded by human endogenous retrovirus group K (HERV-K) are prevalent in rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE),but it remains unclear which proviruses are responsible for this autoantigen. It also remains poorly understood how the transcription of HERV-K loci is regulated in cells that can produce Env.ResultsWe aligned our neutrophil RNA sequencing data to the new telomere-to-telomere reference genome and found uniquely mapping transcripts from HERV-K101,K102,K104,K108,K109,K117 and ERVK5,of which only K102,K108,and K109 encode an intact Env. Expression of K102 and K108 were higher in SLE than in healthy donors or RA (padj < 0.05). Transcripts from these proviruses increased in response to interferon-α in monocytes and neutrophils from RA patients and healthy donors,but not in SLE,presumably because they have chronically elevated type I interferons in vivo. Indeed,HERV-K expression was significantly higher in SLE patients with high type I interferon gene signature. Tumor necrosis factor-α and other cytokines and TLR ligands also induced HERV-K102 and K108 transcripts. Interferon-α also increased detectable Env protein in monocytes,macrophages,and neutrophils from RA patients. Among the genes for epigenetic silencers of HERV-K,only TRIM28 was significantly decreased in SLE patients with high interferons (padj = 0.00024).ConclusionsOur data establish a role for interferons in maintaining increased HERV-K expression in SLE and suggest that interferons or other cytokines can upregulate HERV-K to similar levels in RA. A transient increase may also accompany normal immune responses,suggesting that endogenous retroviruses may have been co-opted for efficient immune responses.Supplementary InformationThe online version contains supplementary material available at 10.1186/s13100-025-00371-y.
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Y. Lei et al. (Sep 2025)
Journal of Neuroinflammation 22 1
LncBADR promotes T cell-mediated autoimmunity by binding Mccc1 and Pcca to regulate BCAAs degradation
T cell dysfunction is a pivotal driving factor in autoimmune diseases,yet its underlying regulatory mechanisms remain incompletely understood. The role of long non-coding RNAs (lncRNAs) in immune regulation has gradually been recognized,although their functional mechanisms in T cells remain elusive. This study focuses on lncBADR (LncRNA Branched-chain Amino acids Degradation Regulator),elucidating its mechanism by which it regulates branched-chain amino acids (BCAAs) metabolism to influence T cell effector functions. Mice with specific knockout of lncBADR (T celllncBADR−/−) exhibited markedly ameliorated experimental autoimmune encephalomyelitis (EAE) symptoms. Mechanistic investigations revealed that lncBADR inhibits BCAAs degradation by binding to the enzymes Mccc1 and Pcca,leading to the accumulation of BCAAs within T-cells. This,in turn,activates the mTOR-Stat1 signaling pathway,promoting IFN-γ secretion and exacerbating EAE pathology. In contrast,knockout of lncBADR restored BCAAs degradation,significantly reducing IFN-γ secretion in T cells and suppressing their pathogenic functions. Further studies demonstrated that high-BCAAs feeding partially reversed the protective effects of lncBADR knockout,indicating that lncBADR plays a crucial role in autoimmune inflammation by regulating BCAAs metabolism. This study offers new insights into targeting lncBADR or modulating BCAAs metabolism as potential therapeutic strategies for autoimmune diseases.
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D. Shishkova et al. (Sep 2025)
International Journal of Molecular Sciences 26 18
Isolation of Primary Human Saphenous Vein Endothelial Cells, Human Internal Thoracic Artery Endothelial Cells, and Human Adipose Tissue-Derived Microvascular Endothelial Cells from Patients Undergoing Coronary Artery Bypass Graft Surgery
Primary human endothelial cells represent an essential tool to model endothelial dysfunction and to screen interventions for its treatment. Here,we developed a protocol for the synchronous isolation of primary human saphenous vein endothelial cells (HSaVEC),human internal thoracic artery endothelial cells (HITAEC),and human microvascular endothelial cells (HMVEC) from SV and ITA utilized as conduits during coronary artery bypass graft surgery and from subcutaneous adipose tissue excised while providing an access to the heart. Treatment by collagenase type IV and magnetic separation with anti-CD31-antibody-coated beads ensured relatively high efficiency of the isolation (≈60% for HSaVEC,≈50% for HITAEC,and ≈20% for HMVEC) and high purity (≥99%) of isolated ECs within ≈2 weeks (HSaVEC),≈2–3 weeks (HITAEC),and ≈3–4 weeks (HMVEC). A colorimetric assay of cell viability and proliferation,as well as real-time bioimpedance monitoring using the xCELLigence instrument,demonstrated high proliferative activity in HSaVEC,HITAEC,and HMVEC,whilst the in vitro tube formation assay indicated their angiogenic potential. The isolation of HSaVEC,HITAEC,and HMVEC from patients undergoing coronary artery bypass graft surgery is a promising option to investigate endothelial heterogeneity,to interrogate endothelial responses to various stresses,and to pinpoint the optimal approaches for restoring endothelial homeostasis,thereby reproducing them within the bedside-to-bench-to-bedside concept.
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L. A. Syding et al. (Sep 2025)
Journal for Immunotherapy of Cancer 13 9
High Treg and PMN-MDSC densities are a hallmark of tertiary lymphoid structures in fatal cases of cervical cancer
BackgroundHigh densities of tertiary lymphoid structures (TLSs) are associated with improved clinical outcomes in various malignancies,including human papillomavirus (HPV)-associated head and neck squamous cell carcinoma (HNSCC). However,the role of TLSs in shaping antitumor immunity in HPV-induced cervical cancer (CESC) remains unclear. Therefore,we analyzed the density,composition,and prognostic impact of TLSs in patients with CESC as well as patients with HNSCC.MethodsMultiplex immunofluorescence,immunohistochemistry,and spatial transcriptomics were used to analyze TLS density and composition in HNSCC and CESC tissue sections with respect to patient prognosis. The spatial approach was supplemented by flow cytometry-based analysis of the polymorphonuclear myeloid-derived suppressor cell (PMN-MDSC) phenotype in freshly resected primary tumor tissues.ResultsAlthough both indications were associated with HPV infection,we confirmed a positive correlation between TLS density and improved overall survival only in patients with HNSCC. The TLS composition differed markedly between HNSCC and CESC samples,with a shift toward high regulatory T cell (Treg) and PMN-MDSC abundance in CESC samples. The highest Treg and PMN-MDSC levels were observed in patients with CESC who died of the disease. CESC-infiltrating PMN-MDSCs showed high arginase 1 expression,which correlated with diminished T-cell receptor (TCR)ζ chain expression in CESC-infiltrating T cells. Additionally,the high number of PMN-MDSCs in TLSs was associated with the absence of HPV-specific T cells in CESC.ConclusionsUnlike in HNSCC,the composition of TLSs,rather than their quantity,was associated with the overall survival of patients with CESC. High numbers of Tregs and PMN-MDSCs infiltrating immature TLSs prevail in patients with CESC who succumbed to the disease and seem to affect tumor-specific immune responses.
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S. Kim et al. (Aug 2025)
Molecules 30 17
BI-5756 Reduces Graft-Versus-Host Disease Through CB1-Mediated Treg Upregulation
Cannabinoid receptor 1 (CB1) has been implicated in multiple inflammatory diseases by regulating pro-inflammatory mediators or altering immune cell polarization. However,the expression and direct functional role of CB1 in T cells remain largely unexplored. Here,we demonstrate that primary murine T cells express CB1 and that its novel agonist,BI-5756,directly increases the frequencies of regulatory T cells (Tregs) in primary murine pan T cells after activation. In addition,BI-5756 exhibits an in vivo protective effect against graft-versus-host disease (GvHD),an allogeneic T cell-mediated inflammatory complication after allogeneic hematopoietic cell transplantation (allo-HCT),resulting in an improved overall survival with enhanced platelet recovery and reconstitution of bone marrow-derived B and T cells. BI-5756 also directly suppresses tumor cell growth and upregulates MHC I,MHC II,and CD80 on tumor cells,which may subsequently enhance T cell-mediated anti-tumor responses in mixed lymphocyte reaction with A20 cells. The ability of BI-5756 to increase Tregs was significantly abrogated by rimonabant,a potent and selective CB1 antagonist,suggesting that the immunomodulatory effect of BI-5756 is mediated via CB1. In summary,BI-5756,a potent CB1 agonist,increases Tregs while preserving anti-tumor responses in vitro and effectively reduces GvHD in vivo.
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S. L. Calzi et al. (Aug 2025)
Cells 14 17
Targeting Diabetic Retinopathy with Human iPSC-Derived Vascular Reparative Cells in a Type 2 Diabetes Model
Purpose: To investigate the therapeutic potential of inducible pluripotent stem cell (hiPSC)-based vascular repair,we evaluated two vascular reparative cell populations,CD34+ cells derived from hiPSC (hiPSC-CD34+) and endothelial colony forming cells (ECFCs) derived from hiPSC (iPS-ECFCs),alone and in combination,in a type 2 diabetic (db/db) mouse model of DR. Methods: hiPSC-CD34+ cells (1 × 104) or iPSC- ECFCs (1 × 105) alone or in combination (1.1 × 105) were injected into the vitreous of immunosuppressed db/db mice with six months of established diabetes. One month post-injection,mice underwent electroretinography (ERG) and optical coherence tomography (OCT) to evaluate functional and structural retinal recovery with iPSC administration. Immunohistochemistry (IHC) was used to assess recruitment and incorporation of cells into the retinal vasculature. Retinas from the experimental groups were analyzed using Functional Proteomics via Reverse Phase Protein Array (RPPA). Results: Functional assessment via ERG demonstrated significant improvements in retinal response in the diabetic cohorts treated with either hiPSC-derived CD34+ cells or hiPSC-ECFCs. Retinal thickness,assessed by OCT,was restored to near-nondiabetic levels in mice treated with hiPSC-CD34+ cells alone and the combination group,whereas hiPSC-ECFCs alone did not significantly affect retinal thickness. One month following intravitreal injection,hiPSC-CD34+ cells were localized to perivascular regions,whereas hiPSC-ECFCs were observed to integrate directly into the retinal vasculature. RPPA analysis revealed interaction-significant changes,and this was interpreted as a combination-specific,non-additive host responses (m6A,PI3K–AKT–mTOR,glycolysis,endothelial junction pathways). Conclusions: The studies support that injection of hiPSC-CD34+ cells and hiPSC-ECFCs,both individually and in combination,showed benefit; however,iPSC combination-specific effects were identified by measurement of retinal thickness and by RPPA.
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