Biology subjects

Lei, W.

Publications and source records attributed to Lei, W..

At least 19 recordsLinked to original sources

bioRxiv2026

OmniTCR: a foundation model unifying T cell receptor recognition prediction and conditional sequence generation

T cell receptor (TCR) recognition prediction and receptor generation are traditionally modelled separately, leaving vast TCR sequence collections disconnected from smaller TCR-peptide-MHC datasets. Here we present OmniTCR, a 113-million-parameter autoregressive foundation model pretrained on 328 million formatted human immune-sequence records. Sequence-type tokens and complementary component orders enable joint learning from individual TCR chains and partial or complete TCR-pMHC associations. On unseen epitopes, OmniTCR achieved AUPRCs of 0.7009 for peptide-TCR{beta}; recognition and 0.8235 for TCR-pMHC interaction prediction, exceeding the strongest evaluated comparators by 0.3396 and 0.3451, respectively. It distinguishes cancer from healthy repertoires across 11 independent pan-cancer cohorts (mean AUROC, 0.9436). The model achieved the highest sequence recovery on internal and external generation benchmarks. Structural modelling supported the plausibility of selected pMHC-conditioned CDR3{beta}; candidates. OmniTCR bridges heterogeneous immune sequence data, providing a foundation for computational immunology and receptor design.

bioinformatics↗

bioRxiv2025

Multimodal gene and targeted drug therapy for chronic myelogenous leukemia: Computational target analysis and therapeutic validation

Developing an efficient and safe therapy necessitates a mechanistic understanding of the complex underlying pathology and manipulation of the multiple pathways at the molecular and genetic level. Network-based simulation of chronic myeloid leukemia (CML), a relatively well-understood cancer model, revealed the dynamics of simultaneously expressing pro-apoptotic BIM and silencing pro-survival MCL-1 in combination with the BCR-ABL-targeted tyrosine kinase inhibitor dasatinib. Viral/nonviral chimeric nanoparticles (ChNPs) composed of a BIM-expressing adeno-associated virus (AAV) core and a degradable polymeric shell that encapsulates MCL-1 siRNA (BIM/MCL-1 ChNPs) synergistically and selectively killed BCR-ABL+ CML cells in combination with dasatinib. In a mouse CML model, the BIM/MCL-1 ChNPs and dasatinib combination therapy suppressed proliferation of BCR-ABL+ hematopoietic cells and prevented leukemic infiltration of organs. The synergistic anti-leukemic effect was further pronounced in an acute phase model of the disease. This study investigated a strategy of developing a versatile and tunable multimodal therapy assisted by a computational toolset that analyzes the molecular foundation of a disease and predicts therapeutic response. The interdisciplinary approach developed and validated in this study can be used in discovering new therapies for cancer and other diseases. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=182 SRC="FIGDIR/small/656072v1_ufig1.gif" ALT="Figure 1"> View larger version (43K): org.highwire.dtl.DTLVardef@1e3632borg.highwire.dtl.DTLVardef@1839f12org.highwire.dtl.DTLVardef@4060c0org.highwire.dtl.DTLVardef@8ff0de_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOGraphical abstractC_FLOATNO summarizing the study design and approach. A schematic representation of the integrated in silico and in vivo pipeline utilized in the study. The workflow begins with in silico simulations, including Boolean network modeling and protein-protein interaction (PPI) network analyses, leading to target discovery, optimized nanoparticle design, and validation in pathological contexts. This was followed by therapeutic efficacy assessments of BIM/MCL-1 ChNPs and their combination with dasatinib in BCR-ABL+ leukemia models in vitro and in vivo. C_FIG

cancer biology↗

bioRxiv2025

ST-FFPE-mIF: Integrating Spatial Transcriptomics and Multiplex Immunofluorescence in Formalin-Fixed Paraffin-Embedded Tissues Using Stereo-seq

Stereo-seq is the state-of-the-art technique, which allows capturing of spatial transcriptomic data at sub-cellular resolution and in large scale of view. Stereo-seq FFPE technique is recently launched with the capability to obtain spatially resolved gene expression in FFPE tissue sections. However, the omic information is limited to transcriptome. To delineate spatial molecular hierarchy from transcriptome to phenome, we present the protocol that implements nine-plex immunofluorescence staining with detection of spatial transcriptomics in one FFPE tissue section (short for ST-FFPE-mIF). This protocol details the modified biochemistry procedure and also provides analytical framework to achieve single-cell resolution through nuclear or membrane staining-based cell segmentation. We demonstrated the application of ST-FFPE-mIF in colorectal cancer sample to illustrate how ST-FFPE-mIF facilitates a robust analysis of spatially resolved multi-omic data at the single-cell level.

biochemistry↗

bioRxiv2025

Immune and Mutational Profile of Gene-Edited Low-Immunogenic Human Primary Cholangiocyte Organoids

Primary human cells cultured in organoid format have great promise as potential regenerative cellular therapies. However, their immunogenicity and mutational profile remain unresolved, impeding effective long-term translation to the clinic. In this study we report, for the first time, the generation of human leukocyte antigen (HLA)-I and HLA-II knock-out expandable human primary cholangiocyte organoids (PCOs) using CRISPR-Cas9 as a potential universal low-immunogenic therapy for bile duct disorders. HLA-edited PCOs (ePCOs) displayed the same phenotypical and functional characteristics as parental un-edited PCOs. Despite minimal off-target edits, single-molecule DNA-sequencing demonstrated that ePCOs and PCOs acquire substantial mutations in culture at similar rates but without evident selection for cancer-driver mutations. ePCOs induced reduced T cell-mediated immunity and a donor-dependent NK cell cytotoxicity in vitro and evaded cytotoxic responses with increased graft survival in humanized mice in vivo. Our findings have important implications for assessment of safety and immunogenicity of organoid cellular therapies.

immunology↗

bioRxiv2024

Longevity or Well-being? A Dual-Dimension Structure of Neuroticism

The development of personality traits is often viewed as evolutionarily adaptive. Current neuroticism research, however, predominantly highlights its negative health impacts, neglecting its potential evolutionary advantages. We propose that neuroticisms inter-individual variability can be structured into two distinct geometric dimensions. One, named the Emotional Reactivity-Instability/Distress Spectrum (ERIS), correlates strongly with longevity and is associated with chronic diseases and risk-averse lifestyle. This dimension is underpinned by evolutionarily conserved subcortical brain regions and genes. The other, resembling the overall neuroticism score, is primarily linked to mental and stress-related disorders, as well as life satisfaction. It involves higher-order emotional brain regions and is genetically enriched in human-accelerated regions. Collectively, these dimensions represent a dual-strategy personality framework that optimizes survival and well-being, with the former being evolutionarily conservative and the latter potentially a unique human adaptation.

neuroscience↗

bioRxiv2024

Endogenous glucocorticoids are required for normal macrophage activation and gastric Helicobacter pylori immunity

Glucocorticoids are steroid hormones well-known for their potent anti-inflammatory effects. However, their immunomodulatory properties are multifaceted. Increasing evidence suggests that glucocorticoid signaling promotes effective immunity and that disruption of glucocorticoid signaling impairs immune function. In this study, we conditionally deleted the glucocorticoid receptor (GR) in the myeloid lineage using the LysM-Cre driver (myGRKO). We examined the impact on macrophage activation and gastric immune responses to Helicobacter pylori, the best-known risk factor of gastric cancer. Our results indicate that compared to WT, GRKO macrophages exhibited higher expression of proinflammatory genes in steroid-free conditions. However, when challenged in vivo, GRKO macrophages exhibited aberrant chromatin landscapes and impaired proinflammatory gene expression profiles. Moreover, gastric colonization with Helicobacter revealed impaired gastric immune responses and reduced T cell recruitment in myGRKO mice. As a result, myGRKO mice were protected from atrophic gastritis and pyloric metaplasia development. These results demonstrate a dual role for glucocorticoid signaling in preparing macrophages to respond to bacterial infection but limiting their pathogenic activation. In addition, our results support that macrophages are critical for gastric anti- Helicobacter immunity. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=159 SRC="FIGDIR/small/575574v1_ufig1.gif" ALT="Figure 1"> View larger version (34K): org.highwire.dtl.DTLVardef@7d5281org.highwire.dtl.DTLVardef@1b39ca2org.highwire.dtl.DTLVardef@f081caorg.highwire.dtl.DTLVardef@1d9215d_HPS_FORMAT_FIGEXP M_FIG C_FIG

immunology↗

bioRxiv2024

Immunogenicity of autologous and allogeneic human primary cholangiocyte organoids

Primary human cells cultured in 3D organoid format have great promise as potential regenerative cellular therapies, but their immunogenicity has not yet been fully characterized. In this study, we use in vitro co-cultures and in vivo humanized mouse experimental models to examine the human immune response to autologous and allogeneic primary cholangiocyte organoids (PCOs). Our data demonstrate that PCOs upregulate the expression of HLA-I and HLA-II in inflammatory conditions. The immune response to allogeneic PCOs is driven by both HLA-I and HLA-II and is substantially ameliorated by donor-recipient HLA matching. Autologous PCOs induce a low-level immune infiltration into the graft site, while allogeneic cells display evolving stages of immune rejection in vivo. Our findings have important implications for the design and clinical translation of autologous and allogeneic organoid cellular therapies. ONE-SENTENCE SUMMARYThe immune response to human primary cholangiocyte organoids is ameliorated by donor-recipient HLA matching.

immunology↗

bioRxiv2023

Molecular identification of wide-field amacrine cells in mouse retina that encode stimulus orientation

Visual information processing in the retina is sculpted by a diverse group of inhibitory interneurons called amacrine cells. For most of the >60 amacrine cell types, molecular identities and specialized functional attributes remain unknown. Here, we developed an intersectional genetic strategy to target a group of wide-field amacrine cells (WACs) in mouse retina that co-express the transcription factor Bhlhe22 and the Kappa Opioid Receptor (KOR; B/K WACs). B/K WACs feature straight, unbranched dendrites spanning over 0.5 mm (~15 deg visual angle) and produce non-spiking responses to either light increments or decrements. Two-photon dendritic population imaging reveals Ca2+ signals tuned to the physical orientations of B/K WAC dendrites, signifying a robust structure-function alignment. B/K WACs establish divergent connections with multiple retinal neurons, including unexpected connections with non-orientation-tuned ganglion cells and bipolar cells. Our work sets the stage for future comprehensive investigations of the most enigmatic group of retinal neurons: WACs.

neuroscience↗

bioRxiv2023

An Endogenous Aryl Hydrocarbon Receptor Ligand Induces Preeclampsia-like Phenotypes: Transcriptome, Phosphoproteome, and Cell Functions

BackgroundPreeclampsia (PE) is one hypertensive disorder and a leading cause of maternal and fetal mortality and morbidity during human pregnancy. Aryl hydrocarbon receptor (AhR) is a transcription factor, which regulates vascular functions. Exogenous and endogenous AhR ligands can induce hypertension in animals. However, if dysregulation of endogenous AhR ligands contributes to the pathophysiology of PE remains elusive. MethodsWe measured AhR activities in human maternal and umbilical vein sera. We also applied physiological, cellular, and molecular approaches to dissect the role of endogenous AhR ligands in vascular functions during pregnancy using pregnant rats and primary human umbilical vein endothelial cells (HUVECs) as models. ResultsPE elevated AhR activities in human umbilical vein sera. Exposure of pregnant rats to an endogenous AhR ligand, 2-(1H-indole-3-carbonyl)-thiazole-4-carboxylic acid methyl ester (ITE) increased blood pressure and proteinuria, while decreased uteroplacental blood flow and reduced fetal and placental weights, all of which are hallmarks of PE. ITE dampened vascular growth and fetal sex-specifically altered immune cell infiltration in rat placentas. ITE also decreased cell proliferation and cell monolayer integrity in HUVECs in vitro. RNA sequencing analysis revealed that ITE dysregulated transcriptome in rat placentas and HUVECs in a fetal sex-specific manner. Bottom-up phosphoproteomics showed that ITE disrupted phosphoproteome in HUVECs. These ITE-dysregulated genes and phosphoproteins were enriched in biological functions and pathways which are highly relevant to diseases of heart, liver, and kidney, vascular functions, inflammation responses, cell death, and kinase inhibition. ConclusionsDysregulation of endogenous AhR ligands during pregnancy may lead to the development of PE with underlying impaired vascular functions, fetal sex-specific immune cell infiltration and transcriptome, and phosphoproteome. Thus, this study has provided a novel mechanism for the development of PE and potentially other forms of hypertensive pregnancies. These AhR ligand-activated genes and phosphoproteins might represent promising therapeutic and fetal sex-specific targets for PE-impaired vascular functions.

pathology↗

bioRxiv2023

Efficient inhibition of fusion inhibitor HY3000 peptide to SARS-CoV-2 emerging EG.5, EG.5.1 and BA.2.86 variants

SARS-CoV-2 continues to evolve and spread. Recently, the Omicron EG.5 lineage, bearing an additional F456L mutation in spike (S) protein compared to its ancestor XBB.1.9.2, and its sub-variant EG.5.1, which carries a further Q52H mutation, have raised concerns due to their increased prevalence and extended immune escape properties. Additionally, an alarming variant, BA.2.86, has also garnered global concern because it contains over 30 amino acid mutations in its S protein compared to BA.2, including more than 10 changes in receptor-binding domain (RBD), reminiscent of the appearance of the Omicron variant in late 2021. Therefore, there is an urgent need to assess the effectiveness of current vaccines and therapeutics against EG.5, EG.5.1 and BA.2.86. In our previous work, we reported the design and broad-spectrum antiviral activity of a peptide fusion inhibitor HY3000 against SARS-CoV-2 and its variants including XBB.1.5. Here, we continued to evaluate the inhibitory potency of the HY3000 peptide against the prevailing EG.5 and EG.5.1, as well as XBB.1.16, FL.1.5.1, FY.3 and BA.2.86. Our data indicated that the peptide retained its potent inhibitory activities against these variants, indicating its potential as a good virus fusion inhibitor with broad-spectrum therapeutic effect against current and future SARS-CoV-2 variants. Currently, the HY3000 has been finished in Phase II clinical trial in China and has also been approved to conduct clinical investigation by U.S. Food and Drug Administration (FDA), suggesting a good application prospect against the ongoing COVID-19.

microbiology↗

bioRxiv2023

Culture substrate stiffness impacts human myoblast contractility-dependent proliferation and nuclear envelope wrinkling

The remarkable self-repair ability of skeletal muscle tissues is driven by muscle stem cells, whose activities are orchestrated by a variety of transient cues present in their microenvironment. Understanding how the cross-interactions of these biophysical and biochemical microenvironmental cues influences muscle stem cells and their progeny is crucial in strategizing remedies for pathological dysregulation of these cues in aging and disease. In this study, we investigated the cell-level influences of extracellular matrix ligands in the context of mechanically tuned culture substrates on primary human myoblast contractility and proliferation within 16 hours of plating. We found that fibronectin led to stronger stiffness-dependent responses in myoblasts compared to laminin and collagen as revealed by cell spreading area, focal adhesion morphology, traction stresses, and proliferation. While we did not observe stiffness-dependent changes in cell fate signatures at this early time-point, an analysis of the stiffness-sensitive myoblast proteome uncovered an enrichment for differentiation associated signatures on 17 kPa culture substrates, in addition to distinct profiles with relation to metabolism, cytoskeletal regulation, ECM interactions, and nuclear component enrichment. Interestingly, we found that softer substrates increased the incidence of myoblasts with a wrinkled nucleus, and that the extent of wrinkling could predict Ki67 expression. While nuclear wrinkling and Ki67 expression could be controlled by pharmacological manipulation of cellular contractility, cellular traction stresses did not correlate with nuclear envelope wrinkling level. These results provide new insights into the regulation of human myoblast stiffness-dependent contractility response by ECM ligands and also highlight a link between myoblast contractility and proliferation.

bioengineering↗

bioRxiv2022

A non-human primate model with Alzheimer's disease-like pathology induced by hippocampal overexpression of human tau

Alzheimers disease (AD) is one of the most burdening diseases of the century with no disease-modifying treatment yet. Non-human primates (NHPs) share genetic, anatomical and physiological similarities with humans, making them an ideal model for investigating the pathogenesis and therapeutics of AD. However, the applications of NHPs in AD research have been hindered by the paucity of spontaneous or induced monkey models for AD due to their long generation time, ethical considerations and technical challenges in making genetically modified monkeys. Here we developed an AD-like NHP model by overexpressing human tau in bilateral hippocampi of adult rhesus macaque monkeys. We evaluated the pathological features of these monkeys with immunostaining, cerebrospinal fluid (CSF) analysis, magnetic resonance imaging (MRI), positron emission tomography (PET) scan, and behavioral tests. We demonstrated that after hippocampal overexpression of human tau, the rhesus macaque monkeys displayed multiple pathological features of AD, including neurofibrillary tangle formation, neuronal loss, hippocampal atrophy, neuroinflammation, A{beta} clearance deficit, blood vessel damage and cognitive decline. This work establishes a human tau-induced AD-like NHP model that may facilitate mechanistic studies and therapeutic treatments for AD.

neuroscience↗

bioRxiv2022

Soil nitrogen impacts the rhizosphere microbial community owing to microbial hitchhiking

Microbial hitchhiking demonstrates that some nonmotile microbes utilize trans-species motility to traverse their environment; however, whether driving forces, such as plants and nitrogen, affect microbial hitchhiking is not clear. In our study, we explored the effects of plants and nitrogen fertilizer on Bacillus-hitchhiking by setting filter membranes and different nitrogen fertilizer concentration gradients. In the experimental treatment, we added a filter membrane to the soil to prevent hitchhiking. In the absence of plants, nitrogen alone had little influence on motile bacteria and hitchhiking. However, Bacillus contents were significantly impacted by the nitrogen concentration when the plants were rooted, leading to a great variation in cell motility function according to the functional analysis in the soil microbial community. After applying the filter membrane, there were no significant differences in Bacillus contents, microbial community structure or cell motility functional abundance, which illustrated that hitchhiking impacted the microbial community. Our analysis of co-occurrence between bulk soil motile bacteria (Bacillus) and rhizosphere bacteria also confirmed this. The correlation between bulk soil motile bacteria and the rhizosphere microbial community was strong in the groups with suitable nitrogen concentrations without filter membranes and was weak at all nitrogen levels in the no-membrane treatments. Thus, we concluded that plants and different nitrogen doses synergistically altered the soil microbiome by hitchhiking, whose effect depends on nitrogen.

microbiology↗

bioRxiv2022

SRSF10 is essential for progenitor spermatogonia expansion by regulating alternative splicing

Alternative splicing expands the transcriptome and proteome complexity and plays essential roles in tissue development and human diseases. However, how alternative splicing regulates spermatogenesis remains largely unknown. Here, using germ cell-specific knockout mouse model, we demonstrated that the splicing factor Srsf10 is essential for spermatogenesis and male fertility. Depletion of Srsf10 in germ cells had little effect on the formation of SSCs but impeded the expansion of progenitor spermatogonia, leading to the failure of spermatogonia differentiation and meiosis initiation. This was further evidenced by the decreased expression of progenitor cell markers in bulk RNA-seq, and much less progenitor and differentiating spermatogonia in single-cell RNA-seq data. Furthermore, the expression of genes involved in cell cycle was abnormal in all subtypes of spermatogonia identified in single-cell RNA-seq data. Notably, using isolated spermatogonia, we found that Srsf10 depletion disturbed the alternative splicing of hundreds of genes, which were preferentially associated with cell cycle, mitotic cell cycle checkpoint and germ cell development, including Dazl, Kit, Ret, Sycp1, Nasp and Bora. These data suggest that SRSF10 is critical for the expansion of progenitor spermatogonia by regulating alternative splicing, expanding our understanding of the mechanism underlying spermatogenesis.

developmental biology↗

bioRxiv2021

Intranasal vasopressin like oxytocin increases social attention by influencing top-down control, but additionally enhances bottom-up control

The respective roles of the neuropeptides arginine vasopressin (AVP) and oxytocin (OXT) in modulating social cognition and for therapeutic intervention in autism spectrum disorder have not been fully established. In particular, while numerous studies have demonstrated effects of oxytocin in promoting social attention the role of AVP has not been examined. The present study employed a randomized, double-blind, placebo (PLC)-controlled between-subject design to explore the social- and emotion-specific effects of AVP on both bottom-up and topdown attention processing with a validated emotional anti-saccade eye-tracking paradigm in 80 male subjects (PLC = 40, AVP = 40). Our findings showed that AVP increased the error rate for social (angry, fearful, happy, neutral and sad faces) but not non-social (oval shapes) stimuli during the anti-saccade condition and reduced error rates in the pro-saccade condition. Comparison of these findings with a previous study (sample size: PLC = 33, OXT = 33) using intranasal oxytocin revealed similar effects of the two peptides on anti-saccade errors but a significantly greater effect of AVP on pro-saccades. Both peptides also produced a post-task anxiolytic effect by reducing state anxiety. Together these findings suggested that both AVP and OXT decrease goal-directed top-down attention control to social salient stimuli but that AVP more potently increased bottom-up social attentional processing.

neuroscience↗

bioRxiv2021

Age and Race related changes in Gene Expression during Human PBMC aging

Human immune system functions over an entire lifetime, yet how and why the immune system becomes less effective with age are not well understood. Here, we characterize peripheral blood mononuclear cells transcriptome from 172 healthy adults with 21~90 years of age using RNA-seq and the weighted gene correlation network analyses (WGCNA). These data reveal a set of insightful gene expression modules and representative gene biomarkers for human immune system aging from Asian and Caucasian ancestry, respectively. Among them, the aging-specific modules show an age-related gene expression variation spike around early-seventies. In addition, it is not known whether Asian and Caucasian immune systems go through similar gene expression changes throughout their lifespan, and to what extent these aging-associated changes are shared among ethnicities. We find the top hub genes including NUDT7, CLPB, OXNAD1 and MLLT3 are shared between Asian and Caucasian aging related modules and further validated in human PBMCs from different age groups. Overall, the impact of age and race on transcriptional variation elucidated from this study provide insights into the transcriptional driver of immune aging.

immunology↗

bioRxiv2021

Unravelling processes between phenotypic plasticity and population dynamics in migratory birds

O_LIPopulations can rapidly respond to environmental change via adaptive phenotypic plasticity, which can also modify interactions between individuals and their environment, affecting population dynamics. Bird migration is a highly plastic resource-tracking strategy in seasonal environments. However, the link between the population dynamics of migratory birds and migration strategy plasticity is not well understood. C_LIO_LIThe quality of staging habitats affects individuals migration timing and energy budgets in the course of migration, and can consequently affect individuals breeding and overwintering performance, and impact population dynamics. Given staging habitats being lost in many parts of the world, our goal is to investigate responses of individual migration strategies and population dynamics in the face of loss of staging habitat, and to identify the key processes connecting them. C_LIO_LIWe started by constructed and analysed a general full-annual-cycle individual-based model with a stylized migratory population to generate hypotheses on how changes in the size of staging habitat might drive changes in individual stopover duration and population dynamics, and to identify the key processes connecting them. Next, through the interrogation of census data, we tested these hypotheses by analysing population trends and stopover duration of migratory waterbirds experiencing loss of staging habitat. C_LIO_LIWe found empirical support for our modelling-identified hypotheses: the loss of staging habitat generates plasticity in migration strategies, with individuals remaining on the staging habitat for longer to obtain food due to a reduction in per capita food availability. The subsequent increasing population density on the staging habitat has knock on effects on population dynamics in the breeding and overwintering stage. C_LIO_LIOur results demonstrate how environmental change that impacts one energetically costly life history stage in migratory birds can have population dynamics impacts across the entire annual cycle via phenotypic plasticity. C_LI

ecology↗

bioRxiv2020

Comment on Rapid and efficient in vivo astrocyte-to-neuron conversion with regional identity and connectivity?

Regenerating functional new neurons in the adult mammalian central nervous system (CNS) has been proven to be very challenging due to the inability of neurons to divide and repopulate themselves after neuronal loss. In contrast, glial cells in the CNS can divide and repopulate themselves under injury or disease conditions. Therefore, many groups around the world have been able to utilize internal glial cells to directly convert them into neurons for neural repair. We have previously demonstrated that ectopic expression of NeuroD1 in dividing glial cells can directly convert reactive glial cells into neurons. However, Wang et al. recently posted an article in bioRxiv challenging the entire field of in vivo glia-to-neuron conversion after using one single highly toxic dose of AAV (2x1013 gc/ml, 1 l) in the mouse cortex, producing artifacts that are very difficult to interpret. We present data here that reducing AAV dosage to safe level will avoid artifacts caused by toxic dosage. We also demonstrate with Aldh1l1-CreERT2 and Ai14 reporter mice that lineage-traced astrocytes can be successfully converted into NeuN+ neurons after infected by AAV5 GFAP::NeuroD1. Retroviral expression of NeuroD1 further confirms our previous findings that dividing glial cells can be converted into neurons. Together, the incidence of Wang et al. sends an alarming signal to the entire in vivo reprogramming field that the dosage of viral vectors is a critical factor to consider when designing proper experiments. For AAV, we recommend a relatively safe dose of 1x1010 - 1x1012 gc/ml (~1 l) in the rodent brain for cell conversion experiments addressing basic science questions. For therapeutic purpose under injury or diseased conditions, AAV dosage needs to be adjusted through a series of dose finding experiments. Moreover, we recommend that the AAV results are further verified with retroviruses that mainly express transgenes in dividing glial cells in order to draw solid conclusions.

neuroscience↗