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Song, H.

Publications and source records attributed to Song, H..

At least 19 recordsLinked to original sources

Vaccination targeting the novel endogenous tumor-associated antigen Gpr149 induces protective immunity against checkpoint inhibitor-refractory SB28 glioblastoma

Background: Glioblastoma is a lethal brain tumor notable for its limited spontaneous induction of CD8+ T cell responses. Vaccination may overcome this limitation by generating tumor-specific CD8+ T cells capable of mediating anti-tumor immunity in the brain. However, preclinical vaccine development is constrained by a lack of immunologically stringent glioblastoma models with defined endogenous antigens. We therefore sought to identify endogenous, vaccine-targetable antigens expressed by the immune checkpoint-refractory SB28 syngeneic mouse glioblastoma model and to evaluate their targetability using a heterologous prime-boost regimen with the chimpanzee adenovirus ChAdOx1 and the modified vaccinia Ankara (MVA) viral vector-based vaccines. Methods: RNA sequencing and whole-exome sequencing were used to identify candidate tumor-associated antigens (TAAs) and neoantigens, and tumor-specific expression was validated by RT-qPCR. ChAdOx1 and MVA vectors encoding candidate antigens were generated and evaluated for immunogenicity and anti-tumor efficacy. Antigen-specific CD8+ T cell responses and minimal epitopes were characterized by ex vivo restimulation, MHC-I binding assays, tetramer staining, and tumor cytotoxicity assays. Results: We identified five candidate TAAs (Gpr149, Cdh6, Fbn2, Igf2bp1, and Shox2) but no suitable neoantigen targets in SB28. Vaccination induced CD8+ T cell responses against the candidate TAAs, and immunogenic minimal epitopes were identified for each. Among the candidates, Gpr149 elicited the strongest vaccine-induced CD8+ T cell responses. In mice challenged intracranially with SB28, Gpr149-targeted ChAdOx1/MVA vaccination combined with immune checkpoint blockade significantly prolonged median survival and resulted in long-term survival in 50% of mice, whereas vaccination targeting the other TAAs did not improve survival. CD8+ T cells recognizing the immunodominant Gpr149128-135 epitope (VCYNFYTM) specifically recognized and lysed wild-type SB28 cells, but not Gpr149-knockout SB28 cells, confirming endogenous processing and presentation of the targeted epitope. Conclusions: Gpr149 is an endogenous SB28 tumor antigen that can be effectively targeted by ChAdOx1/MVA vaccination to generate protective anti-tumor immunity against intracranial glioblastoma. Protection was associated with a dominant CD8+ T cell response to the Gpr149128-135 epitope VCYNFYTM. These findings establish endogenously expressed Gpr149 in SB28 as a physiologically relevant model for evaluating antigen-targeted immunotherapies and provide a systematic approach for identifying endogenous vaccine targets in other preclinical models.

immunology↗

The multidrug transporter Pdr5 from Saccharomyces cerevisiae is an ergosterol-modulated efflux pump

The pleiotropic drug resistance ABC transporter Pdr5 and its homologs play a critical role in multidrug resistance of numerous fungi, including pathogens. Previous studies demonstrated that alterations in the composition of the plasma membrane in which Pdr5 is embedded, specifically the ergosterol content, affected transport activity. Here we report the cryo-EM map of Saccharomyces cerevisiae Pdr5 in complex with ATP/ADP at 2.2 [A] resolution, revealing densities on the surface of the transmembrane domains as well as inside the substrate-binding site, that were assigned as ergosterol, identified and quantified by GC-MS, and the sphingolipid M(IP)2C, identified via native MS. The ergosterol molecules are bound to the protein in well-defined grooves and unexpected locations. We found that the activity of Pdr5 follows a Gaussian-like distribution, increasing with the ergosterol-concentration to reach a maximum before declining at higher concentrations, but this modulation was not observed in the presence of cholesterol, the sterol analogue found in mammalian cells. Mutational analysis corroborates the role of a single ergosterol-binding site in the modulation of Pdr5 activity. Our structural analysis identifies a protein-lipid network that could serve as a center for lipid engagement linking the surrounding lipid environment to the substrate-binding region of Pdr5. These findings advance our understanding of Pdr5 function by demonstrating that the lipid environment is closely linked to Pdr5 structure and activity.

biochemistry↗

Computational alternative to cardiac biopsy in multiple myeloma: utilizing the shape of routine laboratory data for the classification of AL cardiac amyloidosis

Background: Patients with multiple myeloma (MM) are at increased risk for light chain cardiac amyloidosis (CA) due to high circulating levels of light chains. ALCA is a clinical diagnosis based on biopsy, cardiac imaging findings of restrictive cardiomyopathy, and serum monoclonal proteins. To overcome these challenges, we have developed machine learning models that accurately predict ALCA status while identifying key diagnostic features based on routine laboratory measurements and using limited data. Methods: Utilizing electronic medical data (EMR) data, we built support vector machine models (SVMs) using the MISTIC framework. Data including diagnosis history, treatment, and laboratory values for patients with MM or monoclonal gammopathy of unknown significance (MGUS) were collected as a retrospective cohort study at Moffit Cancer Center and Research Institute between 2014 and 2019. To utilize the wealth of information in longitudinal EMR data, we fit regression models to the EMR data and used the parameters and characteristics of the fits as features for our SVMs. We tested three different sets of features: descriptive statistics alone, parameters and characteristics of fit only, and both the descriptive statistics and parameters of fit (DescFits). A classifier using raw data at a timepoint proximal to the date of ALCA diagnostic imaging (EchoAdj), as well as analogous random forest and XGBoost models were used for comparison. Findings: SVM classifiers trained on the DescFits feature set (AUC= 1.0) outperformed blind model predictions of the EchoAdj model (AUC = 0.36) and other conventional machine learning approaches in identifying which patients were diagnosed with ALCA. The DescFits model selected features describing the temporal relationship of physiologic parameters including hematologic state, and cardiac and renal function. Interpretation: We demonstrated that the MISTIC SVM framework and the shape of EMR data can aid in identifying patients with cardiac amyloidosis without cardiac biopsy or imaging.

bioengineering↗

Early-life core microbiota are associated with postlarval survival of Penaeus vannamei: A meta-analysis

Larviculture is critical to the production of Penaeus vannamei, the world's leading farmed shrimp species, but remains constrained by erratic postlarval survival. Although early-life microbiome establishment is increasingly recognized as essential for larval health and survival, microbiome-based hatchery interventions are hindered by limited understanding of larval core microbiota. Here, we synthesized publicly available and self-generated 16S rRNA gene amplicon datasets of larval and rearing-water microbiota from 13 studies encompassing seven major producing regions worldwide to characterize shrimp larval core microbiota, their assembly processes, and their associations with larval survival. Although larval prokaryotic communities exhibited stronger geographic variation than developmental-stage succession, a conserved set of dominant bacterial families, including Roseobacteraceae, Vibrionaceae, Flavobacteriaceae, Moraxellaceae, and Pseudoalteromonadaceae, consistently prevailed across developmental stages and regions. By integrating occupancy, persistence, and ecological network centrality analyses, we demonstrated that common, temporal, and ecological core microbiota differ substantially in composition, diversity, stage specificity, and ecological roles in network stability. Compared with non-core taxa, core taxa were generally assembled more deterministically, irrespective of core category, suggesting stronger host selection and/or more rapid dispersal during microbiome establishment. Core microbiota also generally showed stronger associations with postlarval survival than total communities or non-core taxa, although contrasting survival associations among core members indicated that core microbiota are not ecologically homogeneous. Our work provides the first systematic categorization and characterization of larval core microbiota throughout the shrimp larviculture cycle, offering new insights into the ecological significance of core microbiota and identifying potential universal targets for microbiome-based intervention in shrimp larviculture.

microbiology↗

AMPK-dependent brain-wide norepinephrine release promotes recovery from metabolic coma in mice

Coma is a pathological brain state characterized by loss of consciousness. How the brain recovers from coma remains largely unknown. Using mouse models of metabolic coma, we identified an endogenous neuromodulatory pathway that actively promotes coma recovery. In mice subjected to hypoglycemic coma, hypoglycemia triggered AMPK-dependent excitation of nucleus tractus solitarius (NTS) neurons, which activated locus coeruleus (LC) norepinephrine neurons through a glutamatergic NTS-LC circuit. LC activation drives widespread norepinephrine release across cortical and subcortical regions, thereby promoting post-coma arousal. Notably, coma-associated brain-wide norepinephrine release was unconventional in both scale and duration, with a magnitude approximately 10-fold higher than physiological norepinephrine release during sleep-wake cycles. This neuromodulatory process also operated during hypercapnic coma. Vagus nerve stimulation accelerated coma recovery by engaging this endogenous anti-coma mechanism. Our findings uncover an AMPK-dependent brainstem circuit that actively restores arousal from metabolic coma, revealing a neural defense strategy against profound metabolic stress.

neuroscience↗

Impacts of different SETD1A mutations and genetic backgrounds on human induced pluripotent stem cell-derived hippocampal neurons

Abstract Human induced pluripotent stem cells (hiPSCs) provide a translational platform to interrogate the impact of genetic risk factors for various disorders on human biology. It has been a common practice to engineer premature stop codons to model predicted loss-of-function mutations using isogenic hiPSCs, yet effects of mutation position for the same gene and genetic background have been rarely tested systematically and at multiple levels for comparison to those of patient-specific mutations. Ultra-rare, heterozygous, and predicted loss-of-function mutations in the SETD1A gene, which encodes a H3K4 methyltransferase, are highly penetrant genetic risk factors for schizophrenia. Here, we generated a large panel of isogenic heterozygous SETD1A mutant hiPSC lines, including premature stop-codon mutations in one early exon and one late exon in five genetic backgrounds and two patient-specific mutations, to gain insight into molecular, cellular, and functional changes in a disease-relevant and highly pure population of human hippocampal dentate granule cell-like neurons. Our multi-level analyses showed that different SETD1A mutations lead to divergent molecular and cellular phenotypes related to synapses, but convergent neuronal network deficits, while the genetic background influences gene expression with no substantial effects at cellular and network levels. Mechanistic analysis confirmed the early exon patient mutation as loss-of-function, but revealed that the predicted loss-of-function patient mutation in the late exon is likely gain-of-function. Consequently, while all mutations decreased global H3K4me3 levels, deficits were only partially rescued by inhibiting H3K4 demethylase LSD1 for early exon mutations, but not for late exon mutations. Together, these results suggest that highly penetrant mutations can lead to similar cellular and functional phenotypes across different genetic backgrounds, whereas different premature stop-codon mutations could have contrasting impacts due to distinct mechanisms. Our findings have practical implications for applying genome-editing in hiPSCs to model disorders, highlight the value of modeling patient-specific mutations and testing multiple mutations, and suggest the need for tailored mutation-dependent therapeutic strategies.

neuroscience↗

Structural basis of selective phospholipid recognition and local membrane deformation by CTL1

The physiological function of the human choline transporter-like protein CTL1 (SLC44A1) remains elusive despite its implication in key pathophysiological processes. Here we combine cryo-electron microscopy, native mass spectrometry, lipidomics, molecular dynamics simulations and functional assays to characterise the molecular basis of phospholipid recognition by CTL1 and explore its potential molecular role. High-resolution structures of CTL1 in both monomeric and dimeric states reveal a broad amphipathic cavity and an extracellular domain that accommodate multiple phospholipid species, identifying phosphatidylethanolamine, phosphatidylserine, phosphatidylinositol and phosphatidic acid as endogenous CTL1 ligands. Molecular dynamics simulations show spontaneous phospholipid recruitment into these conserved binding sites accompanied by membrane thinning, curvature and local phospholipid reorganisation, with membrane deformation being enhanced upon dimerisation. Functional analyses in mammalian cells and in reconstituted proteoliposomes failed to detect CTL1-mediated choline transport, supporting a function distinct from canonical choline uptake. Together, our findings suggest that CTL1 acts as a phospholipid-binding protein capable of locally deforming the membrane and provide a structural framework linking phospholipid recognition to membrane organisation. These results offer new insights into potential mechanisms underlying the altered phospholipid homeostasis associated with CTL1 dysfunction in neurological diseases and cancer.

biophysics↗

Constructing microbiome co-occurrence networks with confidence: A conditional, nonparametric, inference-based approach

Constructing microbial association networks is a common strategy for exploring relationships among taxa in microbiome studies. Although marginal correlation methods are easy to implement and allow formal inference, they can produce spurious edges driven by indirect associations through other taxa. Conditional graphical-modeling methods aim to recover direct associations, but many rely on Gaussian or linear assumptions and often provide limited uncertainty quantification. We propose a conditional, nonparametric approach based on the scaled expected conditional covariance (SEcov). SEcov measures population-level conditional association by residualizing each taxon with respect to the remaining taxa and scaling the resulting expected conditional covariance. The resulting estimator can incorporate flexible machine-learning methods for conditional-mean estimation and admits asymptotic normal inference, enabling p-values and confidence intervals for taxon-pair associations. We demonstrate through simulation studies that our proposed approach improves network recovery relative to other methods, and we illustrate the new method via construction of a co-occurrence network for the vaginal microbiome during pregnancy. IMPORTANCEHigh-throughput sequencing has made it possible to characterize microbial communities at large scale, and network analysis is widely used to summarize relationships among taxa. However, networks based on marginal correlations may include indirect associations, whereas many conditional graphical models rely on assumptions that may be difficult to justify for sparse, zero-inflated, compositional microbiome data. SEcov offers a practical alternative by estimating conditional associations nonparametrically and attaching inferential uncertainty to individual edges. This allows investigators to construct microbiome networks using statistically interpretable evidence for taxon-pair associations, rather than relying solely on arbitrary correlation cutoffs or regularization tuning parameters.

bioinformatics↗

Multiple roads to swarming: divergent molecular machineries drive the repeated evolution of locusts

Locust swarming, one of nature's most spectacular examples of a repeated emergent polyphenism, has long been suspected to rely on conserved "swarming genes" or shared genomic features. By applying a model-clade approach comparing six species that vary in their degrees of plasticity and collective behavior, we show that the evolution of swarming locusts is not driven by shared genomic features or a universal set of swarming genes. In contrast, we find that this phenomenon evolved through flexible regulatory architectures, in which the degree of behavioral plasticity directly correlates with the total scale of density-responsive gene expression. While different locust species recruit largely non-overlapping gene sets to achieve the same syndrome, these divergent molecular machineries converge on similar higher-level biological functions. Thus, multiple molecular pathways achieve locust swarming, challenging the preconceived notion about the genetic prerequisites to transition from solitary to collective states. Further, we establish that a complex syndrome such as locust swarming emerges through modular regulatory systems that can be amplified, modified, or attenuated across the tree of life.

evolutionary biology↗

Phagocytic activity of perivascular cell promotes CNS injury pathology

Injury, stroke, and neurological diseases cause persistent accumulation of cellular debris that deteriorates lesion microenvironment and impedes central nervous system (CNS) repair. Debris clearance in the injured CNS has long been attributed primarily to microglia and infiltrating macrophages. Here, we identify perivascular cells as previously unrecognized phagocytes that expand after injury and exhibit robust phagocytic activity. Perivascular cell phagocytosis is conserved across multiple mouse models of CNS injury and human stroke lesions. These cells exhibit key hallmarks of phagocytosis, including LC3-associated phagocytosis for efficient lysosomal degradation. Mechanistically, phosphatidylserine serves as the eat-me signal and Axl mediates myelin debris uptake. Myelin phagocytosis drives perivascular cell proliferation, fibrosis and lesion progression. Genetic deletion of Axl in perivascular cells or pharmacological inhibition with the FDA-approved Axl inhibitor Gilteritinib reduces pathology and improves functional recovery after spinal cord injury. Together, these findings establish Axl-dependent perivascular cell phagocytosis as a therapeutic target for CNS repair.

neuroscience↗

PlasChain: an algorithm for improving long plasmid reconstruction from metagenome assemblies

BackgroundPlasmids play a critical role in horizontal gene transfer and the spread of antibiotic resistance. However, recovering complete plasmid sequences from metagenomic samples remains highly challenging due to extensive repeat content, structural heterogeneity, and large variation in plasmid size. Existing methods typically identify plasmids from metagenome assemblies by exploiting coverage differences or detecting minimum-weight cycles in assembly graphs. While effective for dominant plasmids, these approaches often fail to recover low-abundance and long plasmids. ResultsHere we present PlasChain, a novel algorithm designed to improve plasmid assembly and identification from complex metagenomic data. Building upon the cycle-peeling strategy of SCAPP, PlasChain incorporates contig path information and a cycle-merging procedure to prevent long plasmids from being fragmented into multiple shorter cycles. In addition, PlasChain jointly leverages paired-end read alignments, sequence composition patterns, and coverage variation to filter out assembly artifacts and reduce false positives. We evaluated PlasChain against state-of-the-art plasmid assemblers, including SCAPP and metaplasmidSPAdes, using a diverse set of simulated and real metagenomic datasets. Across nearly all benchmarks, PlasChain demonstrates superior performance in recovering long plasmids while maintaining competitive accuracy in assembling short plasmids. Furthermore, analysis of real metagenomic samples shows that PlasChain is capable of assembling previously uncharacterized plasmids, including putative megaplasmids that are typically underrepresented in current plasmid databases. ConclusionsPlasChain is a novel graph-based plasmid assembler that improves the recovery of long plasmids from short-read metagenomic data. Evaluation on diverse simulated and real metagenomic datasets demonstrates that PlasChain consistently outperforms existing plasmid assemblers, especially for long plasmid reconstruction. These results highlight the potential of PlasChain to facilitate comprehensive characterization of plasmid diversity, antimicrobial resistance, and horizontal gene transfer in complex microbial communities. The source code and testing data of PlasChain are freely available at https://github.com/SDU-ACG-Lab/PlasChain. Supplementary InformationThis manuscript is accompanied by a supplementary file.

bioinformatics↗

Hologenomics of xylotrophic bivalves reveals a minimalist, remote-acting evolutionary strategy of wood digestion

Wood constitutes the largest reservoir of biogenic carbon on Earth, yet remarkably few animals can exploit it. While terrestrial wood-feeders like termites rely on highly diverse gut microbiomes, xylotrophic marine bivalves have evolved a fundamentally different approach: a spatially segregated system where intracellular gill symbionts produce enzymes that act remotely within a nearly sterile cecum. However, the genetic and evolutionary basis of this unique symbiosis remains largely elusive. Here, we integrate hologenomics, transcriptomics, and biochemistry of a shallow-water shipworm (Teredo navalis) and a deep-sea borer (Xyloredo sp.). We find that despite diverging approximately 147 million years ago and occupying drastically different habitats, these bivalves maintain a strictly conserved ancestral karyotype and a shared genomic architecture for wood digestion. Our models reveal a clear host-symbiont division of labor. The host genome is specialized for lignin modification and targeted enzyme transport, whereas a highly streamlined symbiont community is responsible for core polysaccharide degradation. Central to this minimalist strategy is a lineage-specific GH5-GH6 dual-catalytic enzyme. By sharing amino acids across proximal binding pockets, this fusion protein unites endo- and exo-cellulase activities, enabling highly synergistic cellulose cleavage without the need for complex microbial communities. Ultimately, our comparative analysis with terrestrial models demonstrates that these marine invertebrates achieve efficient biomass degradation not through microbial expansion, but through extreme functional streamlining and molecular innovation, offering a distinct evolutionary paradigm for marine carbon cycling.

evolutionary biology↗

Histological assessment of integrated human cortical organoid grafts after controlled cortical impact

Rodent models are a mainstay of traumatic brain injury (TBI) research, including investigations into the pathophysiology and treatment of this condition. However, there are fundamental molecular and cellular differences between rodent and human neurons, as well as other cells of the brain. Brain organoids derived from human pluripotent stem cells recapitulate key features of the human brain and have been used to model a variety of neurological disorders. Here, we developed a novel in vivo model of human TBI based on controlled cortical impact (CCI) injuries of human organoid grafts transplanted into the brains of young adult rats. Cortical organoids derived from human induced pluripotent stem cells (iPSCs) were grown for 50-60 days in vitro before transplantation into rat visual cortex. Injures were performed 2 months later, and histological outcomes were examined at 7 or 30 days after injury. Injury cavities in the integrated grafts were identified at both endpoints with a progression toward larger cavities sizes with time. The injured human tissue exhibited evidence of neuroinflammation with elevated numbers of IBA1+ cells and axonal injury with APP+ cells. There was evidence of increased cell proliferation in the injured grafts acutely after injury that decreased with time. The injured grafts also showed evidence of phosphorylated tau aggregates and accumulation of PNAG, a polysaccharide associated with microbial pathogens. These results support the feasibility of using human organoid grafts in rats as a model of TBI, potentially including the study of long-term neurodegeneration and microbial penetration of the brain after injury.

neuroscience↗

OLD sentinel: an abortive tRNase surveys phage replication and DNA defects in RecBCD-compromised cells

OLD, an abortive immunity protein from prophage P2, consists of an ABC ATPase sensor and a TOPRIM nuclease effector -- a core architecture shared by a large protein family, including components of antiphage systems Gabija, PARIS, Septu, and Lamassu. OLD was originally identified for its lethality in recB-deficient cells and inhibition of bacteriophage {lambda} infection, but the mechanisms governing its activation have remained elusive. Here, we present the cryo-EM structure of an inactive OLD tetramer and show that destabilization into dimeric form opens the TOPRIM catalytic site, stimulating tRNA cleavage. This activity arrests translation, a phenotype rescued by phage-encoded tRNAs. We demonstrate that OLD activation is not strictly RecBCD-dependent: OLD binds aberrant DNA structures in recB-deficient cells, but activation during infection requires recognition of single-stranded DNA hairpins at the phage replication origin. Collectively, our findings reveal how host and phage DNA processing factors create a complex landscape controlling OLD-mediated immunity.

molecular biology↗

Slc25a34-Mediated Mitochondrial-to-Cytoplasmic AMP Transport Activates Brown Adipose Tissue Thermogenesis

Metabolites are emerging as signaling molecules that mediate cellular function, extending beyond their well-established roles in metabolic pathways. Members of the solute carrier (SLC) family mediate metabolite transport across cellular compartments, raising the possibility that these proteins may sense environmental stimuli and regulate cellular biological processes by triggering signaling cascades linked to metabolite transport. This study investigated the response of the SLC25A family, a unique set of inner mitochondrial membrane-localized transporters, to cold as an environmental stimulus in mediating metabolic reprogramming; and whether this reprogramming, driven by the metabolites transported by SLC25A proteins, subsequently promotes the activation of thermogenesis in brown adipocytes. After screening members of the SLC25A family for their responsiveness to cold stimuli and brown adipose tissue (BAT) activation, we found that Slc25a34 was robustly induced under these conditions. We further demonstrated that Slc25a34 mediates the transport of adenosine monophosphate (AMP), derived from de novo glucose synthesis, from mitochondria to the cytosol. This transport potentiates AMP-activated protein kinase (AMPK) signaling and glycolytic flux in brown adipocytes, both of which facilitate BAT thermogenesis during cold exposure. Intriguingly, cold exposure directly promoted the activation of peroxisome proliferator-activated receptor gamma (PPAR{gamma}), which transcriptionally upregulated Slc25a34 expression. More importantly, genetic ablation of Slc25a34 impaired BAT thermogenesis. Thus, our study reveals a novel cold-induced metabolite-sensing pathway, where Slc25a34-mediated AMP transport between mitochondria and the cytosol serves as a critical signal for activating BAT thermogenesis. These findings provide compelling evidence that metabolite transport across cellular compartments acts as a key driver of cellular physiology, thereby offering novel insights into metabolite-based therapeutic strategies for metabolic diseases. HighlightsO_LISlc25a34 is cold-responsive and transcriptionally regulated by PPAR{gamma}. C_LIO_LISlc25a34 functions specifically to mediate the mitochondrial-to-cytosolic transport of AMP in brown adipocytes. C_LIO_LIMitochondrially sequestered de novo synthesized AMP acts as a signaling reservoir, and its Slc25a34-mediated efflux to the cytosol activates AMPK and glycolysis, supporting BAT thermogenesis. C_LI

cell biology↗

Critical Scaling Laws and Universality Classes in Biomolecular Condensates

Biomolecular condensates are widespread cellular self-assembled structures with essential functions. There are suggestions of condensates formed by different proteins being near criticality. However, systematic investigation of the criticality of condensates is absent, and critical exponents defining their universality class have not been found. Here, using long-time simulations, we show that condensates exhibit typical critical phenomena, including scale-free spatiotemporal correlations, critical slowing down, divergence of correlation length and dynamic scaling. From these scaling behaviors, a set of critical exponents is determined. Based on dynamic critical exponent, diverse condensates can be divided into two distinct universality classes, arising from differences in their molecular components and interaction types.

biophysics↗

PIGMENT: A deep learning framework for Porcine Immunohistochemistry seGMENTation

Traumatic brain injury produces widespread axonal damage can be assessed histologically using amyloid precursor protein (APP) immunohistochemistry, which labels injured axonal profiles at cellular resolution [1, 2]. However, quantification of APP pathology remains a major bottleneck: annotation is manual, time-consuming, spatially localized, and variable across raters, limiting scalability and reproducibility. This limitation is particularly important in studies that use histology as a reference for neuroimaging or other tissue-level measurements, where cellular APP pathology must be quantified in a spatial form that can be aligned with imaging abnormalities. Here, we introduce PIGMENT, an annotation-efficient deep-learning framework for automated segmentation and quantification of APP-positive pathology in porcine white matter histology. PIGMENT uses a compact SegFormer-B0 architecture trained on 525 expert-annotated 512 x 512-pixel tiles from four APP-stained sections across three pigs. Because APP-positive profiles are sparse, fragmented, stain-variable, and morphologically diverse, PIGMENT combines limited expert labels with APP-specific augmentation designed to model variation in APP-positive intensity, size, continuity, fragmentation, and local tissue context. We evaluated PIGMENT using an instance-level detection rate that measures whether discrete APP-positive components are localized. Across held-out APP-stained data, PIGMENT achieved a mean instance-level detection rate of 0.86. Across the configurations tested, the highest mean detection rate was achieved by a training set that included sections from different animals, suggesting that annotation diversity may be an important factor under limited-label conditions. By extending limited high-confidence expert annotations into whole-section APP burden maps, PIGMENT provides a scalable framework for characterizing the extent and spatial distribution of traumatic axonal injury. These maps may support future studies that align histological injury burden with imaging-derived measures.

neuroscience↗

Systemic viral vector vaccination induces brain resident memory T cells to drive anti-glioblastoma immunity

Glioblastoma is a lethal brain tumor that is unresponsive to current cancer immunotherapeutic approaches, including immune checkpoint blockade (ICB). This suggests that initial priming of T cells, rather than their expansion and licensing as effectors, is a restricting feature in this tumor setting. To overcome the limited initiation of CD8+ T cell responses, we employed a strong heterologous prime-boost vaccination with the simian adenovirus ChAdOx1 and poxvirus modified vaccinia Ankara (MVA). Vaccination conferred therapeutic efficacy against orthotopic, immune checkpoint-blockade (ICB)-refractory SB28 murine glioblastoma. Vaccination was effective against both the murine tumor antigen, P1A, and a newly identified glioblastoma-associated antigen, Gpr149. Additional treatment with ICB provided no additional benefit. Systemic ChAdOx1/MVA vaccination induced robust infiltration of antigen-specific T cells in tumor-challenged brains, the majority of which exhibited a CD103+CD69+CD8+ tissue-resident memory (TRM)-like phenotype. These cells were polyfunctional, durable in brains with sustained tumor control, and mediated tissue-specific immunological memory. Moreover, intracranial adoptive transfer of glioblastoma-derived antigen-specific TRM-like cells was sufficient to protect naive recipients from subsequent orthotopic tumor challenge. Together, these findings establish that viral vector vaccination can generate tumor-specific TRM-like cells that mediate effective anti-glioblastoma immunity, providing a rationale for clinical evaluation of ChAdOx1/MVA-based strategies in glioblastoma.

immunology↗