技术资料

The peripheral immune system is important in neurodegenerative diseases,both in protecting and inflaming the brain,but the underlying mechanisms remain elusive. Alzheimer’s Disease is commonly preceded by a prodromal period. Here,we report the presence of large Aβ aggregates in plasma from patients with mild cognitive impairment ( n = 38). The aggregates are associated with low level Alzheimer’s Disease-like brain pathology as observed by 11 C-PiB PET and 18 F-FTP PET and lowered CD18-rich monocytes. We characterize complement receptor 4 as a strong binder of amyloids and show Aβ aggregates are preferentially phagocytosed and stimulate lysosomal activity through this receptor in stem cell-derived microglia. KIM127 integrin activation in monocytes promotes size selective phagocytosis of Aβ. Hydrodynamic calculations suggest Aβ aggregates associate with vessel walls of the cortical capillaries. In turn,we hypothesize aggregates may provide an adhesion substrate for recruiting CD18-rich monocytes into the cortex. Our results support a role for complement receptor 4 in regulating amyloid homeostasis. Subject terms: Protein aggregation,Neuroimmunology,Dementia View Publication

Nucleotide-binding oligomerization domain-containing protein 1 (NOD1) plays a pivotal role in inducing metabolic inflammation in diabetes. Additionally,the NOD1 ligand disrupts the equilibrium of bone marrow-derived hematopoietic stem/progenitor cells,a process that has immense significance in the development of diabetic retinopathy (DR). We hypothesized that NOD1 depletion impedes the advancement of DR by resolving bone marrow dysfunction. We generated NOD1 −/− -Akita double-mutant mice and chimeric mice with hematopoietic-specific NOD1 depletion to study the role of NOD1 in the bone marrow–retina axis. Elevated circulating NOD1 activators were observed in Akita mice after 6 months of diabetes. NOD1 depletion partially restored diabetes-induced structural changes and retinal electrical responses in NOD1 −/− -Akita mice. Loss of NOD1 significantly ameliorated the progression of diabetic retinal vascular degeneration,as determined by acellular capillary quantification. The preventive effect of NOD1 depletion on DR is linked to bone marrow phenotype alterations,including a restored HSC pool and a shift in hematopoiesis toward myelopoiesis. We also generated chimeric mice with hematopoietic-specific NOD1 ablation,and the results further indicated that NOD1 had a protective effect against DR. Mechanistically,loss of hematopoietic NOD1 resulted in reduced bone marrow-derived macrophage infiltration and decreased CXCL1 and CXCL2 secretion within the retina,subsequently leading to diminished neutrophil chemoattraction and NETosis. The results of our study unveil,for the first time,the critical role of NOD1 as a trigger for a hematopoietic imbalance toward myelopoiesis and local retinal inflammation,culminating in DR progression. Targeting NOD1 in bone marrow may be a potential strategy for the prevention and treatment of DR. The online version contains supplementary material available at 10.1186/s13287-024-03654-y. View Publication

Windham et al. discover that APOE in astrocytes can traffic to lipid droplets (LDs),where it modulates LD composition and size. Astrocytes expressing the Alzheimer’s risk variant APOE4 form large LDs with impaired turnover and increased peroxidation sensitivity. View Publication

Inflammatory bowel disease (IBD) is a chronic inflammatory disease of the gastrointestinal tract with a complex and multifactorial etiology,making it challenging to treat. While recent advances in immunomodulatory biologics,such as antitumor necrosis factor-α (TNF-α) antibodies,have shown moderate success,systemic administration of antibody therapeutics may lead to several adverse effects,including the risk of autoimmune disorders due to systemic cytokine depletion. Transient RNA interference using exogenous short interfering RNA (siRNA) to regulate target gene expression at the transcript level offers an alternative to systemic immunomodulation. However,siRNAs are susceptible to premature degradation and have poor cellular uptake. Graphene oxide (GO) nanoparticles have been shown to be effective nanocarriers for biologics due to their reduced cytotoxicity and enhanced bioavailability. In this study,we evaluate the therapeutic efficacy of GO mediated TNF-α_siRNA using in vitro models of chronic inflammation generated by treating murine small intestines (enteroids) and large intestines (colonoids) with inflammatory agents IL-1β,TNF-α,and LPS. The organotypic mouse enteroids and colonoids developed an inflammatory phenotype similar to that of IBD,characterized by impaired epithelial homeostasis and an increased production of inflammatory cytokines such as TNF-α,IL-1β,and IL-6. We assessed siRNA delivery to these inflamed organoids using three different GO formulations. Out of the three,small-sized GO with polymer and dendrimer modifications (smGO) demonstrated the highest transfection efficiency,which led to the downregulation of inflammatory cytokines,indicating an attenuation of the inflammatory phenotype. Moreover,the transfection efficiency and inflammation-ameliorating effects could be further enhanced by increasing the TNF-α_siRNA/smGO ratio from 1:1 to 3:1. Overall,the results of this study demonstrate that ex vivo organoids with disease-specific phenotypes are invaluable models for assessing the therapeutic potential of nanocarrier-mediated drug and biologic delivery systems. View Publication

The transplantation of spinal cord progenitor cells (SCPCs) derived from human-induced pluripotent stem cells (iPSCs) has beneficial effects in treating spinal cord injury (SCI). However,the presence of residual undifferentiated iPSCs among their differentiated progeny poses a high risk as these cells can develop teratomas or other types of tumors post-transplantation. Despite the need to remove these residual undifferentiated iPSCs,no specific surface markers can identify them for subsequent removal. By profiling the size of SCPCs after a 10-day differentiation process,we found that the large-sized group contains significantly more cells expressing pluripotent markers. In this study,we used a sized-based,label-free separation using an inertial microfluidic-based device to remove tumor-risk cells. The device can reduce the number of undifferentiated cells from an SCPC population with high throughput (ie,>3 million cells/minute) without affecting cell viability and functions. The sorted cells were verified with immunofluorescence staining,flow cytometry analysis,and colony culture assay. We demonstrated the capabilities of our technology to reduce the percentage of OCT4-positive cells. Our technology has great potential for the “downstream processing” of cell manufacturing workflow,ensuring better quality and safety of transplanted cells. View Publication

The generation of the post-cranial embryonic body relies on the coordinated production of spinal cord neurectoderm and presomitic mesoderm cells from neuromesodermal progenitors (NMPs). This process is orchestrated by pro-neural and pro-mesodermal transcription factors that are co-expressed in NMPs together with Hox genes,which are essential for axial allocation of NMP derivatives. NMPs reside in a posterior growth region,which is marked by the expression of Wnt,FGF and Notch signalling components. Although the importance of Wnt and FGF in influencing the induction and differentiation of NMPs is well established,the precise role of Notch remains unclear. Here,we show that the Wnt/FGF-driven induction of NMPs from human embryonic stem cells (hESCs) relies on Notch signalling. Using hESC-derived NMPs and chick embryo grafting,we demonstrate that Notch directs a pro-mesodermal character at the expense of neural fate. We show that Notch also contributes to activation of HOX gene expression in human NMPs,partly in a non-cell-autonomous manner. Finally,we provide evidence that Notch exerts its effects via the establishment of a negative-feedback loop with FGF signalling. View Publication

Primary ciliary dyskinesia (PCD) is a genetically heterogeneous disorder characterized by impaired mucociliary clearance due to defects in motile cilia. This study investigates the impact of loss-of-function mutations in the CFAP300 gene on the ciliary structure and function in three PCD patients. Using a multimodal approach,we integrated molecular genetic testing,transmission electron microscopy,the high-speed video microscopy assay and immunofluorescence staining to analyze ciliary motility and protein expression in both ex vivo and in vitro-obtained ciliary cells. Our results revealed that the pathogenic variant c.198_200delinsCC (p.Phe67ProfsTer10) in CFAP300 led to the absence of the functional CFAP300 protein,the complete loss of outer and inner dynein arms and immotile cilia. Air–liquid interface (ALI)-cultured cells from patients exhibited no ciliary beating,contrasting with healthy controls. Immunostaining confirmed the absence of CFAP300 in patient-derived cilia,underscoring its critical role in dynein arm assembly. These findings highlight the diagnostic utility of ALI cultures combined with functional and protein analyses for PCD,offering a clinically actionable framework that can be readily incorporated into standard diagnostic workflows. View Publication

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. View Publication

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. View Publication

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. View Publication

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. View Publication

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 View Publication