Biology subjects

Guan, T.

Publications and source records attributed to Guan, T..

11 recordsLinked to original sources

bioRxiv2026

An adjuvant for in vivo CAR-T therapy potentiation against solid tumors

In vivo CAR-T therapy offers rapid and controllable T-cell engineering but has yet to achieve durable efficacy against solid tumors. Rather than focusing solely on CAR-T cells, we harness the intact immune system via an in vivo CAR-T adjuvant (iCTA). Composed of aluminum-manganese hydrogel, iCTA can form a spatially confined antigenic and immunostimulatory niche in-situ. By coupling controlled antigen exposure with STING-type I interferon signaling, iCTA not only recruited and reactivated CAR-T cells, but engage the CAR-negative immunocytes with enhanced dendritic-cell antigen presentation and mobilized endogenous antigen-specific T-cell responses. Combined with mRNA-LNP-mediated in vivo CAR-T generation, a single administration of iCTA increased CAR+ T-cell abundance in draining lymph nodes and blood by 2-fold. It also increased T and NK cell infiltration, established an IFNgamma-enriched tumor microenvironment, and reduced exhaustion-associated T-cell states. iCTA improved tumor regression and survival, establishing an adjuvant strategy to enhance in vivo CAR-T therapy.

bioengineering↗

bioRxiv2026

Mapping the chaperonin TRiC/CCT interactome in mouse photoreceptors reveals functional significance for energy metabolism

The eukaryotic chaperonin TRiC/CCT is essential for folding a diverse set of proteins, yet its interactome and functional roles in specialized neurons remain incompletely understood. To investigate TRiC-mediated folding in rod photoreceptors, we generated a transgenic mouse line expressing an epitope-tagged Tcp-1 subunit, enabling purification of intact TRiC complexes from retinal tissue. Mass spectrometry identified 226 TRiC-interacting proteins, including known TRiC substrates and co-chaperones as well as numerous novel candidates enriched in RNA processing, cytoskeletal organization, and cell-cycle regulation. Using a TRiC loss-of-function model in which expression of a short splice isoform of phosducin-like protein (PhLPs) competitively inhibits TRiC activity, we observed marked reductions in canonical TRiC substrates, including tubulins, transducin {beta} subunits, and triosephosphate isomerase, as well as secondary alterations in proteins involved in cytoskeletal stability, membrane trafficking, energy metabolism, and phototransduction. Quantitative metabolomic profiling revealed that TRiC deficiency induces a metabolic "energy crisis" characterized by reduced glycolytic- and tricarboxylic acid cycle intermediates, acylcarnitines, ATP, NAD, and NADH, implicating widespread impairment of glucose utilization, mitochondrial bioenergetics, and fatty acid oxidation. Integrative proteomic-metabolomic analysis identified a small subset of proteins, including Rab10 and Anxa1, as potential drivers of these metabolic disruptions, with defective Rab10-dependent GLUT4 trafficking emerging as a plausible mechanism underlying impaired glucose uptake in TRiC-deficient rods. Finally, experiments using a perpetually unfolded G{beta}1 mutant and G{gamma}1-knockout mice demonstrated that substrate overload sequesters TRiC and competitively displaces other clients, exacerbating proteostasis imbalance. Together, our study provides a comprehensive in vivo mapping of the TRiC interactome in mammalian rods, reveals a connection between TRiC-dependent proteostasis and energy metabolism in rods, and indicates a mechanism by which misfolded TRiC substrates exacerbate a proteostasis imbalance that ultimately results in neurodegeneration.

biochemistry↗

bioRxiv2025

Gene Therapy Rescues Cone Function in an All-cone Retina Mouse Model for Blue Cone Monochromacy with the Most Common C203R Missense Mutation

Blue cone monochromacy (BCM) is an X-linked cone dystrophy characterized by loss of long- (L) and medium-wavelength (M) cone function. A common cause is the C203R missense mutation, which occurs in both OPN1LW and OPN1MW, or in hybrid OPN1LW/OPN1MW opsin genes. Because BCM primarily affects foveal cones, we generated Opn1mwC198R/Opn1sw-/-/Nrl-/- (C198RAC) mice carrying the murine equivalent of the human C203R mutation on an all-cone retinal background. C198RAC mice exhibited absent photopic ERG responses and significantly shortened cone outer segments, recapitulating foveal cone deficits in BCM. Metabolomic profiling further revealed altered retinal metabolism, including reduced cGMP and elevated oxidative stress-related metabolites. To evaluate therapy, we delivered AAV8-Y733F expressing human L-opsin (OPN1LW) cDNA under the cone-specific PR2.1 promoter at 1 and 5 months of age. Treatment restored cone function, regenerated outer segment structures, and provided rescue for at least 5 months post-injection in both early- and late-treatment groups. These results demonstrate that densely packed cones expressing only the C198R mutant opsin remain viable targets for gene therapy. Together, this study establishes the C198RAC mouse as a cone-rich model of BCM and provides compelling preclinical evidence that AAV-mediated gene augmentation can restore cone structure and function, supporting the feasibility of gene therapy for BCM.

molecular biology↗

bioRxiv2025

Molecular Mechanisms Limiting the Therapeutic Window of AAV Gene Therapy in Mouse Models of Blue Cone Monochromacy

Blue cone monochromacy (BCM) is an X-linked retinal disorder caused by mutations in the OPN1LW/OPN1MW gene locus, resulting in impaired cone function and structural degeneration. We conducted a comparative analysis of AAV-mediated gene therapy in Opn1lw/Opn1mw double knockout (DKO) and Opn1mwC198R/Opn1sw-/- (C198R) BCM mouse models and evaluated the therapeutic window, efficacy, and longevity. Our results demonstrate that the AAV8-Y733F capsid achieved superior cone rescue compared to AAV5. While both DKO and C198R models showed similar therapeutic windows and rescue longevity, treatment efficacy decreased markedly in older mutant mice. Structural analysis revealed that aged cones in both models displayed degenerative changes, including mislocalized mitochondria and compromised connecting cilia. At the molecular level, we observed reduced AAV-mediated transgene expression in DKO and C198R older cones, which may result from decreased transduction efficiency, decreased circular episome stability, genome-wide transcription/translation downregulation, targeted mRNA/protein degradation, or overall cone degeneration. Notably, the cone-specific promoters for Pde6c and Cngb3 maintained robust activity in degenerating cones. These findings suggest that combining an efficient AAV serotype with an optimized cone promoter could be a viable approach to extend the therapeutic window and enhance treatment longevity for BCM patients.

molecular biology↗

bioRxiv2024

Sex and Region-Specific Disruption of Autophagy and Mitophagy in Alzheimer's Disease: Linking Cellular Dysfunction to Cognitive Decline

Macroautophagy and mitophagy are critical processes in Alzheimers disease (AD), yet their links to behavioral outcomes, particularly sex-specific differences, are not fully understood. This study investigates autophagy (LC3B-II, SQSTM1) and mitophagy (BNIP3L, BNIP3, BCL2L13) markers in the cortex and hippocampus of male and female 3xTg-AD mice, using western blotting, transmission electron microscopy (TEM), and behavioral tests (novel object recognition and novel object placement). Significant sex-specific differences emerged: female 3xTg-AD mice exhibited autophagosome accumulation due to impaired degradation in the cortex, while males showed fewer autophagosomes, especially in the hippocampus, without significant degradation changes. TEM analyses demonstrated variations in mitochondrial and mitophagosome numbers correlated with memory outcomes. Females had enhanced mitophagy, with higher BNIP3L and BCL2L13 levels, whereas males showed elevated BNIP3 dimers. Cognitive deficits in females correlated with mitochondrial dysfunction in the cortex, while in males, higher LC3B-II levels associated positively with cognitive performance, suggesting protective autophagy effects. Using machine learning, we predicted mitophagosome and mitochondrial numbers based on behavioral data, pioneering a predictive approach to cellular outcomes in AD. These findings underscore the importance of sex-specific regulation of autophagy and mitophagy in AD and support personalized therapeutic approaches targeting these pathways. Integrating machine learning emphasizes its potential to advance neurodegenerative research. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=109 SRC="FIGDIR/small/621097v1_ufig1.gif" ALT="Figure 1"> View larger version (31K): org.highwire.dtl.DTLVardef@1e50ceeorg.highwire.dtl.DTLVardef@b41ac0org.highwire.dtl.DTLVardef@4863d3org.highwire.dtl.DTLVardef@91b2d0_HPS_FORMAT_FIGEXP M_FIG C_FIG Graphical AbstractSex-specific differences in autophagy and mitophagy regulation in Alzheimers disease (AD) are highlighted. Female 3xTg-AD mice show autophagosome accumulation and cognitive deficits, while males exhibit variations in mitophagy markers and behavior.

neuroscience↗

bioRxiv2024

Aberrant Lipid Accumulation leads to Retinal Pigmental Epithelium Dysfunction and Photoreceptor Degeneration in Prcd-deficient mice

Progressive Rod-Cone Degeneration (PRCD) is an integral membrane protein found in photoreceptor outer segment (OS) disc membranes and its function remains unknown. Mutations in Prcd are implicated in Retinitis pigmentosa (RP) in humans and multiple dog breeds. PRCD-deficient models exhibit decreased levels of cholesterol in the plasma. However, potential changes in the retinal cholesterol remain unexplored. In addition, impaired phagocytosis observed in these animal models points to potential deficits in the retinal pigment epithelium (RPE). Here, using a Prcd-/-murine model we investigated the alterations in the retinal cholesterol levels and impairments in the structural and functional integrity of the RPE. Lipidomic and immunohistochemical analyses show a 5-fold increase in the levels of cholesteryl esters (C.Es) and accumulation of neutral lipids in the PRCD-deficient retina, respectively, indicating alterations in total retinal cholesterol. Longitudinal fundus and spectral domain optical coherence tomography (SD-OCT) examinations showed focal lesions and RPE hyperreflectivity. Strikingly, the RPE of Prcd-/- mice exhibited age-related pathological features such as neutral lipid deposits, lipofuscin accumulation, Bruchs membrane (BrM) thickening and drusenoid focal deposits, mirroring an Age-related Macular Degeneration (AMD)-like phenotype. We propose that the extensive lipofuscin accumulation likely impairs lysosomal function, leading to the defective phagocytosis observed in Prcd-/-mice. Our findings support the dysregulation of retinal cholesterol homeostasis in the absence of PRCD. Further, we demonstrate that progressive photoreceptor degeneration in Prcd-/-mice is accompanied by progressive structural and functional deficits in the RPE, which likely exacerbates vision loss over time.

cell biology↗

bioRxiv2023

Suppressing DNMT3a Alleviates the Intrinsic Epigenetic Barrier for Optic Nerve Regeneration and Restores Vision in Adult Mice

The limited regenerative potential of the optic nerve in adult mammals presents a major challenge for restoring vision after optic nerve trauma or disease. The mechanisms of this regenerative failure are not fully understood1,2. Here, through small-molecule and genetic screening for epigenetic modulators3, we identify DNA methyltransferase 3a (DNMT3a) as a potent inhibitor of axon regeneration in mouse and human retinal explants. Selective suppression of DNMT3a in retinal ganglion cells (RGCs) by gene targeting or delivery of shRNA leads to robust, full-length regeneration of RGC axons through the optic nerve and restoration of vision in adult mice after nerve crush injury. Genome-wide bisulfite and transcriptome profiling in combination with single nucleus RNA-sequencing of RGCs revealed selective DNA demethylation and reactivation of genetic programs supporting neuronal survival and axonal growth/regeneration by DNMT3a deficiency. This was accompanied by the suppression of gene networks associated with apoptosis and inflammation. Our results identify DNMT3a as the central orchestrator of an RGC-intrinsic mechanism that limits optic nerve regeneration. Suppressing DNMT3a expression in RGCs unlocks the epigenetic switch for optic nerve regeneration and presents a promising therapeutic avenue for effectively reversing vision loss resulted from optic nerve trauma or diseases.

neuroscience↗

bioRxiv2023

Epigenetic Reshaping through Damage: Promoting Cell Fate Transition by BrdU and IdU Incorporation

Thymidine analogs have long been recognized for their ability to randomly incorporate into DNA. However, their significance in the chemical induction of pluripotency (CIP) remains unclear. Here, we investigated the impact of BrdU/IdU incorporation on the transition of cell fate through DNA damage repair (DDR). Our findings reveal a substantial upregulation of reprogramming mediator gene H3K27ac and H3K9ac, as well as global DNA demethylation in response to DDR. This process creates a hypomethylated environment that promotes cell fate transition. We term this mechanism as Epigenetic Reshaping through Damage (ERD). Overall, our study sheds light on the dynamic interplay between thymidine analogs, DDR, and epigenetic modifications, providing valuable insights into the mechanisms underlying cell fate transition.

cell biology↗

bioRxiv2019

Mass Spectrometry based Metabolomics Deciphered Metabolic Reprogramming That Was Required for Biofilm formation in Uropathogenic Escherichia coli

Biofilm formation plays a key role in many bacteria causing infections, which mostly accounts for high-frequency infectious recurrence and antibiotics resistance. In this study, we sought to compare modified metabolism of biofilm and planktonic populations with UIT89, a predominant agent of urinary tract infection, by combining mass spectrometry based untargeted and targeted metabolomics methods, as well as cytological visualization, which enable us to identify the driven metabolites and associated metabolic pathways underlying biofilm formation. Surprisingly, our finding revealed distinct differences in both phenotypic morphology and metabolism between two patterns. Furthermore, we identified and characterized 38 differential metabolites and associated three metabolic pathways involving glycerolipid metabolism, amino acid metabolism and carbohydrate metabolism that were altered mostly during biofilm formation. This discovery in metabolic phenotyping permitted biofilm formation shall provide us a novel insight into the desperation of biofilm, which enable to develop novel biofilm based treatments against pathogen causing infections, with lower antibiotic resistance.

microbiology↗

bioRxiv2019

Metagenomic Next-generation Sequencing of Cerebrospinal Fluid for the Diagnosis of Central Nervous System Infections: A Multicentre Prospective Study

BackgroundInfectious encephalitis and meningitis are often treated empirically without identification of the causative pathogen. Metagenomic next-generation sequencing (mNGS) is a high throughput technology that enables the detection of pathogens independent of prior clinical or laboratory information.\n\nMethodsThe present study was a multicentre prospective evaluation of mNGS of cerebrospinal fluid (CSF) for the diagnosis of suspected central nervous system infections.\n\nResultsA total of 276 patients were enrolled in this study between Jan 1, 2017 and Jan 1, 2018. Identification of an etiologic pathogen in CSF by mNGS was achieved in 101 patients (36.6%). mNGS detected 11 bacterial species, 7 viral species, 2 fungal species, and 2 parasitic species. The five leading positive detections were varicella-zoster virus (17), Mycobacterium tuberculosis (14), herpes simplex virus 1 (12), Epstein-Barr virus (12), and Cryptococcus neoformans (7). False positives occurred in 12 (4.3%) patients with bacterial infections known to be widespread in hospital environments. False negatives occurred in 16 (5.8%) patients and included bacterial, viral and fungal aetiologies.\n\nConclusionsmNGS of CSF is a powerful diagnostic method to identify the pathogen for many central nervous system infections.

genomics↗

bioRxiv2018

Tumor regression mediated by oncogene withdrawal or erlotinib stimulates infiltration ofinflammatory immune cells in EGFR mutant lung tumors

Epidermal Growth Factor Receptor (EGFR) tyrosine kinase inhibitors (TKIs) like erlotinib are effective for treating patients with EGFR mutant lung cancer; however, drug resistance inevitably emerges. Approaches to combine immunotherapies and targeted therapies to overcome or delay drug resistance have been hindered by limited knowledge of the effect of erlotinib on tumor-infiltrating immune cells. Using mouse models, we studied the immunological profile of mutant EGFR-driven lung tumors before and after erlotinib treatment. We found that erlotinib triggered the recruitment of inflammatory T cells into the lungs. Interestingly, this phenotype could be recapitulated by tumor regression mediated by deprivation of the EGFR oncogene indicating that tumor regression alone was sufficient for these immunostimulatory effects. Erlotinib treatment also led to increased maturation of myeloid cells and an increase in CD40+ dendritic cells. Our findings lay the foundation for understanding the effects of TKIs on the tumor microenvironment and highlights potential avenues for investigation of targeted and immuno-therapy combination strategies to treat EGFR mutant lung cancer.

cancer biology↗