Structure-guided engineering of immunotherapies targeting TRBC1 and TRBC2 in T cell malignancies
Peripheral T cell lymphomas are typically aggressive with a poor prognosis. Unlike other hematologic malignancies,the lack of target antigens to discriminate healthy from malignant cells limits the efficacy of immunotherapeutic approaches. The T cell receptor expresses one of two highly homologous chains [T cell receptor β-chain constant (TRBC) domains 1 and 2] in a mutually exclusive manner,making it a promising target. Here we demonstrate specificity redirection by rational design using structure-guided computational biology to generate a TRBC2-specific antibody (KFN),complementing the antibody previously described by our laboratory with unique TRBC1 specificity (Jovi-1) in targeting broader spectrum of T cell malignancies clonally expressing either of the two chains. This permits generation of paired reagents (chimeric antigen receptor-T cells) specific for TRBC1 and TRBC2,with preclinical evidence to support their efficacy in T cell malignancies. The T cell receptor β-chain is expressed in two isoforms,TRBC1 and TRBC2,with clonally expanded mature T cell lymphomas expressing one of them exclusively,while healthy T cells randomly express either TRBC1 or TRBC2. Here authors show structure-based design of a TRBC2-specific antibody,and depletion of malignant T cells carrying TRBC1 or TRBC2 with CAR-T cells against the cognate receptor chain in murine models.
View Publication
(Feb 2024)
The Journal of Experimental Medicine 221 3
PROTAC-mediated NR4A1 degradation as a novel strategy for cancer immunotherapy
The study introduces a new immunotherapy for treating melanoma and other cancers by developing a PROTAC that degrades NR4A1,an intracellular nuclear factor that plays a crucial role in immune suppression. An effective cancer therapy requires killing cancer cells and targeting the tumor microenvironment (TME). Searching for molecules critical for multiple cell types in the TME,we identified NR4A1 as one such molecule that can maintain the immune suppressive TME. Here,we establish NR4A1 as a valid target for cancer immunotherapy and describe a first-of-its-kind proteolysis-targeting chimera (PROTAC,named NR-V04) against NR4A1. NR-V04 degrades NR4A1 within hours in vitro and exhibits long-lasting NR4A1 degradation in tumors with an excellent safety profile. NR-V04 inhibits and frequently eradicates established tumors. At the mechanistic level,NR-V04 induces the tumor-infiltrating (TI) B cells and effector memory CD8+ T (Tem) cells and reduces monocytic myeloid-derived suppressor cells (m-MDSC),all of which are known to be clinically relevant immune cell populations in human melanomas. Overall,NR-V04–mediated NR4A1 degradation holds promise for enhancing anticancer immune responses and offers a new avenue for treating various types of cancers such as melanoma. Graphical Abstract
View Publication
MicroRNA-21-5p from induced pluripotent stem cells promotes neuroprotection of retinal ganglion cells in optic nerve crush model
IntroductionRetinal ganglion cells (RGCs) are susceptible to degenerative conditions such as glaucoma and traumatic optic neuropathies,which lead to vision loss. MicroRNA-21-5p has demonstrated potential neuroprotective effects,but its mechanisms in optic nerve injury remain underexplored. This study evaluates the neuroprotective role of microRNA-21-5p derived from induced pluripotent stem cells (iPSCs) in an optic nerve crush (ONC) model.Materials and methodsIn vitro qPCR demonstrated that the expression of microRNA-21-5p was increased in the co-culture medium of RGCs and iPSCs. Subsequently,in the in vivo experiments,we used a microRNA-21-5p agonist to assess its protective effects on RGCs. RNA sequencing was then performed in a mouse ONC model after treatment with a microRNA-21-5p agonist to explore the mechanisms underlying its neuroprotective effects on RGCs.ResultsAs demonstrated in our previous experiments,the RGCs-iPSCs co-culture group led to a higher survival rate of RGCs,as indicated by live/dead cell staining,compared to the RGCs-only group. Quantitative PCR (qPCR) results revealed a significant increase in the expression of microRNA-21-5p in the medium of the RGCs-iPSCs co-culture group. Furthermore,the survival rate of mouse retinal RGCs treated with a microRNA-21-5p agonist was significantly greater than that of the control group. Lastly,RNA sequencing of the retina from microRNA-21-5p agonist-treated mice indicated that microRNA-21-5p plays a protective role in RGCs by downregulating the expression of several genes,including Irf1,Ccl4,Itk,Cxcr2,Dclre1c,Traf1,Traf2,Rbl1,Cxcl5,Cxcl3,Cxcl1,Cxcl9,Il2rg,Cd3e,Cd3d,Cxcl10,Ccl5,Ccl12,Tap1,and Cxcr4.ConclusionMicroRNA-21-5p derived from iPSCs can enhance the survival rate of RGCs in the ONC model. This suggests that microRNA-21-5p may represent a novel and effective strategy for repairing RGC damage. Such a strategy could potentially be realized through the modulation of apoptosis,T-cell regulatory pathways,or TNF-? signaling.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12886-025-04244-z.
View Publication
(Oct 2024)
BMC Psychiatry 24 1
Patient iPSC-derived neural progenitor cells display aberrant cell cycle control, p53, and DNA damage response protein expression in schizophrenia
BackgroundSchizophrenia (SCZ) is a severe psychiatric disorder associated with alterations in early brain development. Details of underlying pathomechanisms remain unclear,despite genome and transcriptome studies providing evidence for aberrant cellular phenotypes and pathway deregulation in developing neuronal cells. However,mechanistic insight at the protein level is limited.MethodsHere,we investigate SCZ-specific protein expression signatures of neuronal progenitor cells (NPC) derived from patient iPSC in comparison to healthy controls using high-throughput Western Blotting (DigiWest) in a targeted proteomics approach.ResultsSCZ neural progenitors displayed altered expression and phosphorylation patterns related to Wnt and MAPK signaling,protein synthesis,cell cycle regulation and DNA damage response. Consistent with impaired cell cycle control,SCZ NPCs also showed accumulation in the G2/M cell phase and reduced differentiation capacity. Furthermore,we correlated these findings with elevated p53 expression and phosphorylation levels in SCZ patient-derived cells,indicating a potential implication of p53 in hampering cell cycle progression and efficient neurodevelopment in SCZ.ConclusionsThrough targeted proteomics we demonstrate that SCZ NPC display coherent mechanistic alterations in regulation of DNA damage response,cell cycle control and p53 expression. These findings highlight the suitability of iPSC-based approaches for modeling psychiatric disorders and contribute to a better understanding of the disease mechanisms underlying SCZ,particularly during early development.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12888-024-06127-x.
View Publication
(Nov 2024)
Development (Cambridge,England) 151 22
SMPD4-mediated sphingolipid metabolism regulates brain and primary cilia development
ABSTRACTGenetic variants in multiple sphingolipid biosynthesis genes cause human brain disorders. A recent study looked at people from 12 unrelated families with variants in the gene SMPD4,a neutral sphingomyelinase that metabolizes sphingomyelin into ceramide at an early stage of the biosynthesis pathway. These individuals have severe developmental brain malformations,including microcephaly and cerebellar hypoplasia. The disease mechanism of SMPD4 was not known and so we pursued a new mouse model. We hypothesized that the role of SMPD4 in producing ceramide is important for making primary cilia,a crucial organelle mediating cellular signaling. We found that the mouse model has cerebellar hypoplasia due to failure of Purkinje cell development. Human induced pluripotent stem cells lacking SMPD4 exhibit neural progenitor cell death and have shortened primary cilia,which is rescued by adding exogenous ceramide. SMPD4 production of ceramide is crucial for human brain development. Summary: Mouse and human stem cell models of SMPD4 loss of function demonstrate that SMPD4 promotes cilia function and neural development.
View Publication
(Jun 2024)
Materials Today Bio 26 4
Nanofiber-microwell cell culture system for spatially patterned differentiation of pluripotent stem cells in 3D
The intricate interplay between biochemical and physical cues dictates pluripotent stem cell (PSC) differentiation to form various tissues. While biochemical modulation has been extensively studied,the role of biophysical microenvironments in early lineage commitment remains elusive. Here,we introduce a novel 3D cell culture system combining electrospun nanofibers with microfabricated polydimethylsiloxane (PDMS) patterns. This system enables the controlled formation of semispherical human induced pluripotent stem cell (hiPSC) colonies,facilitating the investigation of local mechanical stem cell niches on mechano-responsive signaling and lineage specification. Our system unveiled spatially organized RhoA activity coupled with actin-myosin cable formation,suggesting mechano-dependent hiPSC behaviors. Nodal network analysis of RNA-seq data revealed RhoA downstream regulation of YAP signaling,DNA histone modifications,and patterned germ layer specification. Notably,altering colony morphology through controlled PDMS microwell shaping effectively modulated the spatial distribution of mechano-sensitive mediators and subsequent differentiation. This study provides a cell culture platform to decipher the role of biophysical cues in early embryogenesis,offering valuable insights for material design in tissue engineering and regenerative medicine applications. Graphical abstractImage 1
View Publication
(Apr 2024)
Nature Communications 15
Single-cell analyses reveal transient retinal progenitor cells in the ciliary margin of developing human retina
The emergence of retinal progenitor cells and differentiation to various retinal cell types represent fundamental processes during retinal development. Herein,we provide a comprehensive single cell characterisation of transcriptional and chromatin accessibility changes that underline retinal progenitor cell specification and differentiation over the course of human retinal development up to midgestation. Our lineage trajectory data demonstrate the presence of early retinal progenitors,which transit to late,and further to transient neurogenic progenitors,that give rise to all the retinal neurons. Combining single cell RNA-Seq with spatial transcriptomics of early eye samples,we demonstrate the transient presence of early retinal progenitors in the ciliary margin zone with decreasing occurrence from 8 post-conception week of human development. In retinal progenitor cells,we identified a significant enrichment for transcriptional enhanced associate domain transcription factor binding motifs,which when inhibited led to loss of cycling progenitors and retinal identity in pluripotent stem cell derived organoids. Formation of the retina during development involves the coordinated action of retinal progenitor cells and their differentiated cell types,which is key for producing a functioning eye. Here the authors provide a detailed atlas of human retinal development,combining scRNA-seq and spatial transcriptomics,and identify key genetic factors that mediate retinal progenitor cell proliferation and differentiation.
View Publication
(Jun 2025)
Acta Neuropathologica 149 1
Analysis of the splicing landscape of the frontal cortex in FTLD-TDP reveals subtype specific patterns and cryptic splicing
Dysregulation of TDP-43 as seen in TDP-43 proteinopathies leads to specific RNA splicing dysfunction. While discovery studies have explored novel TDP-43-driven splicing events in induced pluripotent stem cell (iPSC)-derived neurons and TDP-43 negative neuronal nuclei,transcriptome-wide investigations in frontotemporal lobar degeneration with TDP-43 aggregates (FTLD-TDP) brains remain unexplored. Such studies hold promise for identifying widespread novel and relevant splicing alterations in FTLD-TDP patient brains. We conducted the largest differential splicing analysis (DSA) using bulk short-read RNAseq data from frontal cortex (FCX) tissue of 127 FTLD-TDP (A,B,C,GRN and C9orf72 carriers) and 22 control subjects (Mayo Clinic Brain Bank),using Leafcutter. In addition,long-read bulk cDNA sequencing data were generated from FCX of 9 FTLD-TDP and 7 controls and human TARDBP wildtype and knock-down iPSC-derived neurons. Publicly available RNAseq data (MayoRNAseq,MSBB and ROSMAP studies) from Alzheimer’s disease patients (AD) was also analyzed. Our DSA revealed extensive splicing alterations in FTLD-TDP patients with 1881 differentially spliced events,in 892 unique genes. When evaluating differences between FTLD-TDP subtypes,we found that C9orf72 repeat expansion carriers carried the most splicing alterations after accounting for differences in cell-type proportions. Focusing on cryptic splicing events,we identified STMN2 and ARHGAP32 as genes with the most abundant and differentially expressed cryptic exons between FTLD-TDP patients and controls in the brain,and we uncovered a set of 17 cryptic events consistently observed across studies,highlighting their potential relevance as biomarkers for TDP-43 proteinopathies. We also identified 16 cryptic events shared between FTLD-TDP and AD brains,suggesting potential common splicing dysregulation pathways in neurodegenerative diseases. Overall,this study provides a comprehensive map of splicing alterations in FTLD-TDP brains,revealing subtype-specific differences and identifying promising candidates for biomarker development and potential common pathogenic mechanisms between FTLD-TDP and AD.Supplementary InformationThe online version contains supplementary material available at 10.1007/s00401-025-02901-7.
View Publication
(Jun 2024)
Nature Communications 15
HNF4A and HNF1A exhibit tissue specific target gene regulation in pancreatic beta cells and hepatocytes
HNF4A and HNF1A encode transcription factors that are important for the development and function of the pancreas and liver. Mutations in both genes have been directly linked to Maturity Onset Diabetes of the Young (MODY) and type 2 diabetes (T2D) risk. To better define the pleiotropic gene regulatory roles of HNF4A and HNF1A,we generated a comprehensive genome-wide map of their binding targets in pancreatic and hepatic cells using ChIP-Seq. HNF4A was found to bind and regulate known (ACY3,HAAO,HNF1A,MAP3K11) and previously unidentified (ABCD3,CDKN2AIP,USH1C,VIL1) loci in a tissue-dependent manner. Functional follow-up highlighted a potential role for HAAO and USH1C as regulators of beta cell function. Unlike the loss-of-function HNF4A/MODY1 variant I271fs,the T2D-associated HNF4A variant (rs1800961) was found to activate AKAP1,GAD2 and HOPX gene expression,potentially due to changes in DNA-binding affinity. We also found HNF1A to bind to and regulate GPR39 expression in beta cells. Overall,our studies provide a rich resource for uncovering downstream molecular targets of HNF4A and HNF1A that may contribute to beta cell or hepatic cell (dys)function,and set up a framework for gene discovery and functional validation. Here,the authors generated a genome-wide map of the global targets bound by HNF4A and HNF1A in beta cells and hepatic cells,and highlighted notable downstream pathways and target genes that may influence beta cell function. This approach also shed light on a potentially activating effect of a HNF4A type 2 diabetes risk variant.
View Publication