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PubMed2026

Assembly and Characterization of the First Complete Mitochondrial Genome of Tussilago farfara L.: Insights into Biological Functions and Phylogenetic Relationships within the Asteraceae Family.

Tussilago farfara L., a member of the Asteraceae family, is an economically valuable species due to its edible and medicinal properties. To elucidate the structural characteristics, genetic mechanisms, and evolutionary pathways of the organelle genomes of T. farfara, we sequenced, assembled, and annotated its mitochondrial genome for the first time. The complete mitochondrial genome of T. farfara spans 306,024 bp and contains 33 mitochondrial protein-coding genes (PCGs), 3 rRNAs, and 22 tRNAs. Analysis of the nucleotide substitution rate and genetic diversity revealed that most mitochondrial genome genes may have undergone purifying selection, indicating a slow evolutionary rate and a relatively conserved genomic structure. We further identified 13 fragments of chloroplast-derived DNA integrated into the mitochondrial genome, evidencing intracellular gene transfer. Collinearity analysis showed that Arctium lappa shares the most extensive mitochondrial homologous sequences and the highest sequence similarity with T. farfara. Phylogenetic analysis based on the mitochondrial genome helped to clarify the evolutionary and taxonomic position of T. farfara within the Asteraceae family. The mitochondrial genome sequence of T. farfara provides a valuable genomic resource for species identification and for evolutionary studies within the Asteraceae family.

Genome, Mitochondrial↗

PubMed2026

DNM1L depletion leads to accelerated heteroplasmy shifting of m.10191C allele through ATG7-dependent pathways.

Nucleotide composition bias in mitochondrial DNA (mtDNA) makes the heavy strand prone to form a DNA secondary structure called a guanine quadruplex (G4). This secondary structure has been shown to inhibit polymerase processivity in vitro. We previously identified pathogenic mtDNA variants that lead to increased G4-forming propensity, including a T to C mutation at m.10191 (m.10191 T > C) that causes Leigh syndrome. Cells treated with G4 binding agent (G4BA) berberine show a reduction in m.10191C pathogenic heteroplasmy levels. To help better understand the underlying mechanism behind berberine-induced heteroplasmy shift, we examined the relationship between mitochondrial fission and berberine-mediated shift. Here we show that knockdown of the fission factor DNM1L leads to an accelerated heteroplasmy shift towards the healthy mtDNA allele, lowering m.10191C by 10% in 3 weeks, compared to the 5 weeks required for berberine alone. The specific mechanism involves ATG7, as knockdown of ATG7 is able to partially delay this accelerated heteroplasmy shift. Taken together, we show that DNM1L knockdown is able to accelerate berberine-induced m.10191C heteroplasmy shifting through an autophagy-related mechanism.

Humans↗

PubMed2026

In Situ Hybridization and RT-PCR Detection of Nervous Necrosis Virus in Fourfinger Threadfin, Eleutheronema tetradactylum, in Taiwan.

Between April and July 2020, suspected outbreaks of nervous necrosis virus (NNV) infection were observed in fourfinger threadfin (Eleutheronema tetradactylum) fingerling hatcheries in Pingtung County, southern Taiwan. Affected fish exhibited spiral swimming behaviour and abdominal distension, resulting in mortality rates between 50% and 100%. Histopathological examination showed severe vacuolation in the brain and ocular tissues, with large oval and/or irregular basophilic cytoplasmic inclusion bodies in the brain. Phylogenetic analysis of the viral replicase (RNA1) and capsid protein (RNA2) genes revealed high nucleotide sequence identities among the isolates in this study, with sequence similarity rates of 96.9%-99% for RNA1 and 98.2%-99.0% for RNA2 compared to RGNNV reference strains available in the NCBI GenBank database. This is the first detection of betanodavirus in fourfinger threadfin in Taiwan, using RT-PCR and ISH. A positive correlation between elevated water temperatures and disease severity indicates the need for year-round surveillance and genomic analysis to clarify the epidemiology of FTNNV. The data suggest that infected eggs may facilitate the vertical transmission of Betanodavirus. Crucially, utilising virus-free broodstock, alongside routine health screening and environmental control, is essential for mitigating NNV risks in fourfinger threadfin aquaculture.

Animals↗

PubMed2026

Molecular Determinants and Therapeutic Targeting of Stop Codon Readthrough in Eukaryotic Translation.

Accurate translation termination is essential for proteome integrity and in eukaryotes is primarily governed by the release factors eRF1 and eRF3, which ensure precise recognition of stop codons and efficient release of nascent polypeptides. However, proteome integrity is challenged by mutations that generate premature termination codons (PTCs), leading to truncated, nonfunctional proteins and degradation of the aberrant transcript via nonsense-mediated mRNA decay (NMD). Collectively, these events account for ∼1800 human genetic diseases. Translational readthrough, the process by which near-cognate tRNAs decode stop codons and allow ribosomes to continue elongation beyond the stop codon, represents a possibility to suppress PTCs and restore full-length protein synthesis. Initially discovered in viruses as a mechanism to expand coding capacity, readthrough is now recognized as a regulated feature of eukaryotic gene expression influenced by both cis-acting sequence elements and trans-acting factors. Recent evidence highlights the remarkable context dependence of readthrough, revealing variation across transcripts, tissues, and developmental stages. In this review, we examine the molecular determinants that define stop codon recognition and readthrough efficiency, with particular emphasis on nucleotide context. We further discuss the mechanisms and binding sites of small molecules that promote PTC readthrough, and summarize the clinical development landscape of readthrough-inducing compounds for the treatment of diseases caused by nonsense mutations.

Humans↗

PubMed2026

Uncovering hidden complexity in the Apis mellifera mitotranscriptome: a polyadenylation-centered perspective.

Mitochondrial transcription is gaining increasing attention as researchers seek to better understand the full coding potential of mitochondrial DNA (mtDNA). Emerging evidence suggests that mtDNA may encode additional elements beyond classical oxidative phosphorylation genes, pointing to a more complex transcriptional architecture than previously recognized. In this study, we explored the mitochondrial transcriptome of Apis mellifera (Insecta: Hymenoptera), with a particular focus on polyadenylation-associated features. Our analysis revealed that both sense and antisense transcripts undergo polyadenylation, although transcript abundance and poly(A) tail lengths varied markedly across mitochondrial genes. Several transcripts exhibited alternative isoforms, either extended or truncated, frequently including intergenic regions. These regions may represent functional non-coding elements or structural variants rather than conventional untranslated regions (UTRs). Interestingly, some transcripts also contained non-templated nucleotide additions particularly cytosine residues immediately upstream of the poly(A) tails. Monocistronic units that included portions of downstream intergenic regions were among the most abundantly represented, suggesting a possible regulatory role for these sequences. To experimentally validate our in silico findings, we performed RT-qPCR to assess relative gene expression and applied 3' RACE-PCR to define transcript boundaries. These approaches confirmed the presence of multiple transcript isoforms and supported the involvement of polyadenylation in shaping mitochondrial RNA diversity. Together, our findings reveal a previously underappreciated level of complexity in the A. mellifera mitochondrial transcriptome and highlight the potential regulatory significance of polyadenylation dynamics and intergenic region transcription.

Animals↗

PubMed2026

Whole genome sequencing of unusual Hepatitis C virus subtypes and drug resistance analysis during direct-acting antiviral therapy in India.

INTRODUCTION AND OBJECTIVES: Pangenotypic direct-acting antivirals (DAA) are effective against highly prevalent Hepatitis C virus (HCV) subtypes, but have been clinically validated almost exclusively in high-income countries. Unusual HCV subtypes may carry natural polymorphisms, potentially impacting DAA susceptibility. We conducted full-genome characterization and resistance analysis of unusual HCV subtypes in patients receiving DAA treatment. PATIENTS AND METHODS: In this prospective hospital-based study, eligible patients were screened for anti-HCV antibodies and active infection was confirmed by diagnostic 5'NCR-based HCV RNA detection. Genotyping was performed by core region sequencing, and viral load quantified by real-time PCR. For whole genome sequencing, multiplex primers were designed using alignments of global reference sequences. Sequencing was carried out using the Oxford Nanopore Technology platform. Phylogenetic analysis used multiple sequence alignment and the HCV-GLUE resource for resistance-associated substitution (RAS) analysis. RESULTS: Predominant genotype was genotype 3 in 64.3% (n = 45); genotype 6 in 21.4% (n = 15); and genotype 1 in 14.2% (n = 10). Unusual HCV subtype 6xa was detected in two patients and showed no NS5A resistance mutations. One genotype 3b patient relapsed at 24 weeks post-DAA treatment completion and carried NS5A resistance-associated substitutions 30 K and 31 M both at baseline and at relapse, conferring high-level resistance to NS5A inhibitors. CONCLUSION: This is the first report from India of whole genome sequencing of HCV subtype 6xa. The identification of NS5A resistance mutations in the 3b relapse case underscores challenges for global HCV elimination strategies.

Humans↗

PubMed2026

Systematic review of the mutations in the active antigenic site Ø of the prefusion F protein of the Respiratory Syncytial Virus (RSV) following the implementation of monoclonal antibody prophylaxis.

BACKGROUND: Monoclonal antibody (mAb) nirsevimab, which targets the antigenic site Ø of the prefusion F protein (pre-F) of RSV, was introduced for RSV prophylaxis in several countries. METHODS: A systematic search was conducted between January 1, 2022, and July 31, 2026 for studies analyzing substitutions within the epitope of pre-F RSV protein, which is the target of nirsevimab, after the implementation of the mAb. We searched across PubMed, Scopus, Web of Science and ClinicalTrial.gov for studies involving children with confirmed RSV infection, that conducted genomic analysis. RESULTS: Seven studies (five observational and two randomized controlled trials) including 2156 RSV-positive samples (RSV-A: 1347, RSV-B: 809) were analyzed. RSV-A strains showed limited variability within antigenic site Ø, with K65R being the most common substitution and K209E being the only intermediate-resistance RSV-A substitution. RSV-B strains demonstrated substantially higher substitution frequencies, particularly involving I206M, Q209R, and S211N. Most identified substitutions appeared to represent naturally occurring polymorphisms and retained susceptibility to nirsevimab, while multiple RSV-B substitutions and combinations involving residues 64-68 and 204-208 demonstrated reduced susceptibility or high-level resistance. Resistance-associated variants were detected in 28 of 2156 (1.3%) RSV-positive samples and exclusively among nirsevimab breakthrough infections. In a sub-analysis restricted to nirsevimab-treated individuals, resistance-associated variants were significantly more frequent among RSV-B than RSV-A (9.8% vs 0.5%; p < 0.001). CONCLUSION: Most substitutions that were detected within the nirsevimab antigenic site reflect ongoing natural RSV evolution and do not significantly affect nirsevimab susceptibility. However, detection of resistance-associated variants highlights the importance of continuous genomic and phenotypic surveillance.

Humans↗

PubMed2026

Form and function of actin impacts actin health and aging.

The actin cytoskeleton is a fundamental and highly conserved structure that functions in diverse cellular processes, yet its direct contribution to organismal aging remains unclear. Here, we systematically interrogated how genetic and pharmacologic perturbations of actin structure and function influence lifespan and various hallmarks of aging in Caenorhabditis elegans. Whole-animal and tissue-specific knockdown of actin and key actin-binding proteins (ABPs)-arx-2 (Arp2/3), unc-60 (cofilin), and lev-11 (tropomyosin)-led to premature disruption of filament organization, reduced lifespan, and tissue-specific physiological defects. Actin dysfunction also displayed a more "aged" transcriptome using previously validated transcriptomics clocks, and broadly exacerbated many age-associated phenotypes, including mitochondrial dysfunction, lipid dysregulation, loss of proteostasis, impaired autophagy, and intestinal barrier failure. Pharmacological destabilization with Latrunculin A mirrored genetic knockdowns, while mild stabilization with Jasplakinolide modestly extended lifespan, emphasizing that optimal and finely tuned actin function is critical for healthy aging. Finally, analysis of human genome-wide association data revealed that common ACTB polymorphisms correlate with differences in age-related decline in gait speed, suggesting some links between aging and actin across organisms. Taken together, our results provide a comprehensive and publicly accessible resource that maps, for the first time, how changes in actin integrity correlate with diverse aging phenotypes across tissues. This descriptive framework is intended to enable future mechanistic discovery by offering a deep, unbiased dataset that can be integrated with emerging studies to define how actin dynamics can potentially influence aging.

actin↗

PubMed2026

Conserved host-exclusive oligonucleotide motifs enriched in pathogenic genes of human oncogenic viruses.

Comparative viral genomics can reveal sequence-level constraints influencing virus-host interactions. Relative minimal absent words (rMAWs) are short oligonucleotide motifs present in viral genomes but completely absent from the host, potentially reflecting selective pressures related to host adaptation and immune evasion. Using the EAGLE algorithm and the GRCh38 human reference genome, we systematically screened for prevalent rMAWs (prMAWs) across six major human oncogenic viruses: Epstein-Barr virus (EBV), hepatitis B virus (HBV), hepatitis C virus (HCV), human papillomavirus (HPV), human T-cell leukemia virus type 1 (HTLV-1), and human herpesvirus 8/Kaposi's sarcoma-associated herpesvirus (HHV-8/KSHV). highly conserved 11- and 12-bp prMAWs were identified in EBV, HBV, HTLV-1, and HHV-8/KSHV, with sequence prevalences ranging from 91.5% to 97.9%. Conversely, no short prMAWs were detected in HCV or HPV, likely reflecting differences in genome architecture, mutation rates, and long-term host adaptation to the human host. Importantly, the identified host-exclusive motifs exhibited non-random genomic distribution and were preferentially embedded within viral genes central to replication, persistence, immune modulation, and oncogenesis, including EBNA-1 (EBV), HBx (HBV), Tax-associated regions (HTLV-1), and lytic replication genes of HHV-8/KSHV. Notably, all detected prMAWs were enriched in GC nucleotides and exhibited marked CpG over-representation, suggesting sequence constraints associated with epigenetic regulation and viral persistence. Collectively, these highly conserved, host-exclusive signatures offer promising, candidates for sequence-directed approaches in the diagnosis, monitoring, and investigation of virus-associated cancers.

Humans↗

PubMed2026

Sexual selection purges mutation load, but not overall genetic diversity, decreasing vulnerability to extinction.

Theory suggests sexual selection will enhance population viability by purging deleterious alleles. However, direct genomic evidence for this fundamental idea is scarce and contradictory. We combined long-term experimental evolution with whole-genome resequencing to directly test how sexual selection affects mutation load, genomic divergence, and extinction risk in small populations (maximum Ne = 40) of Tribolium castaneum. After 156 generations, populations evolving under strong sexual selection carried substantially fewer deleterious alleles than populations under weak sexual selection, based on both individual-level estimates of missense and nonsense variants and population-level Rxy analyses, indicating more efficient purging of deleterious alleles. In contrast, nucleotide diversity and runs of homozygosity were similar across treatments, indicating that purging acted most strongly on deleterious variation, and that reduced mutation load in these small populations under strong sexual selection was not explained by demographic effects. Importantly, population-level mutation load estimates best explained extinction risk under inbreeding, directly linking sexual selection to purging and population viability. Genome scans of high and low sexual selection populations revealed peaks of divergence, which included genes involved in courtship, sex discrimination, and seminal fluid proteins. Our results provide direct genomic evidence that sexual selection can reduce mutation load without eroding standing genetic diversity and thus adaptive potential, while driving adaptive divergence in reproductive traits. This beneficial purging may help explain the widespread prevalence of sexual reproduction in nature despite inherent costs and have important ramifications as to how we manage populations of conservation concern.

Animals↗

PubMed2026

Genomic and Molecular Interaction Analysis of NodD1 in a Novel Bradyrhizobium yuanmingense sp. B64 Isolate for Nodulation and Symbiosis of Legume Plants.

Rhizobial bacteria are known for their ability to fix nitrogen for leguminous plants and their essential function for sustainable agriculture. This study characterizes the taxonomic status and functional potential of the Bradyrhizobium B64 isolate using integrated genomic and molecular approaches. The whole genome of the B64 isolate was sequenced via Illumina paired-end technology. Species delimitation was performed using average nucleotide identity (ANI) and digital DNA-DNA Hybridization (dDDH). The NodD1 protein structure was modeled using AlphaFold3 and validated by Ramachandran plot analysis. Molecular docking was then conducted to evaluate interactions between NodD1 and four signaling flavonoids: Apigenin, Daidzein, Genistein, and Naringenin. Genomic analysis revealed a maximum ANI of 94.4% and dDDH values between 51.4 and 62.4%. Since these values fall below the standard prokaryotic thresholds (ANI < 95%; dDDH < 70%), the B64 isolate is identified as a novel species. Physiological assays confirmed nitrogen fixation (1.97 ppm), IAA production (3.67 ppm), and phosphate solubilization (26.10 ppm). Structural validation showed 100% of NodD1 residues in allowed regions, ensuring high model reliability. Docking simulations demonstrated strong binding affinities across all flavonoids, with binding free energies ranging from - 8.8 to - 9.0 kcal/mol. Daidzein exhibited the highest thermodynamic stability (- 9.0 kcal/mol), whereas apigenin showed the most extensive residue interaction network. The B64 isolate is a novel Bradyrhizobium species with a high symbiotic capacity. The stable NodD1-flavonoid interactions provide a molecular basis for efficient nodulation, positioning B64 as a promising candidate for developing lipo-chitooligosaccharide (LCO)-based biofertilizers.

Bradyrhizobium↗

PubMed2026

Development and protective efficacy of a live attenuated vaccine candidate against goose astrovirus.

Goose astrovirus (GAstV) is a significant pathogen affecting goslings by inducing visceral gout, yet no commercial vaccine is currently available. This study involved the serial passaging of the GAstV-GXNN strain in LMH cells to investigate alterations in viral replication, genomic stability, and pathogenicity, as well as to assess the potential of a vaccine candidate. The findings indicated that the viral titer increased progressively with each passage, reaching 107.35 TCID50/mL by the 120th passage (GAstV-GXNNP120). Whole-genome sequencing revealed the presence of 6, 19, 26, and 28 nucleotide mutations at the 30th, 60th, 90th, and 120th passages, respectively. Pathogenicity assays demonstrated a reduction in virulence with successive passages, culminating in the complete attenuation of GAstV-GXNNP120, which did not induce clinical signs or lesions in one-day-old goslings. Following five successive passages in goslings, the attenuated strain exhibited stable genetic characteristics without any reversion to virulence. Goslings aged one day, inoculated with GAstV-GXNNP120 at dosages ranging from 102.0 to 105.0 TCID50, developed neutralizing antibodies by the third day post-vaccination. Antibody levels increased in a dose-dependent manner, peaking at day 21 and remaining elevated through day 42. Challenge experiments utilizing the virulent GAstV-GXNN strain revealed that groups vaccinated with doses of 103.0 TCID50 and above achieved complete protection. These groups exhibited no clinical symptoms or pathological damage post-challenge, and both tissue viral loads and virus shedding levels were significantly reduced compared to the control group. Consequently, the minimum effective vaccination dose was established at 103.0 TCID50. These results provide a crucial foundation for the development of a live attenuated GAstV vaccine.

Animals↗

PubMed2026

Single-cell transcriptomics reveals heterogeneous stress responses and Mg2+-mediated survival mechanisms in Lactobacillus delbrueckii subsp. bulgaricus during freeze-drying and storage.

Maintaining the viability of lactic acid bacteria during dehydration and subsequent storage remains a significant challenge. Here, we employed single-cell RNA sequencing to reveal the heterogeneous stress responses of Lactobacillus delbrueckii subsp. bulgaricus, identifying seven distinct transcriptional clusters across the liquid culture, freeze-drying, and storage phases. The dominant clusters in the freeze-drying and storage were not completely consistent, showing significant functional differentiation. Genomic stability may be important for survival during freeze-drying and storage, while intracellular energy homeostasis appears important for viability during storage. The magnesium transporter mgtB was highly expressed in clusters tolerant to freeze-drying and storage, suggesting a critical role for Mg2+ homeostasis. Further experimental validation confirmed that Mg2+ treatment significantly bolstered stress resistance, increasing immediate post-freeze-drying survival by over 2-fold (up to 92.90%) and post-storage survival by over 5-fold (up to 5.98%). Proteomic data indicated that Mg2+ supplementation correlated with the maintenance of several biological functions potentially relevant to bacterial survival during freeze-drying and storage, including DNA repair, translation, and central carbon metabolism. These findings provide a map of microbial stress resistance through population heterogeneity and offer a potential strategy that may be adapted for enhancing the stability of other industrial lactic acid bacteria products.

Freeze Drying↗

PubMed2026

Protein persulfidation emerges as a conserved component of the redox response to DNA damage.

Genotoxic stress is frequently accompanied by alterations in cellular redox homeostasis; however, the mechanisms linking redox regulation to the DNA damage response (DDR) remain incompletely understood. Here, we investigated the early redox response to DNA damage induced by methyl methanesulfonate (MMS) in Saccharomyces cerevisiae, focusing on cysteine oxidative post-translational modifications (PTM). We show that activation of the DNA damage response is accompanied by rapid redox changes that occur in the absence of a generalized oxidative stress response. MMS exposure promotes selective remodeling of cysteine oxidative modifications, characterized by decreased free thiols, robust induction of protein persulfidation, and comparatively modest changes in sulfenylation. These alterations are accompanied by increased intracellular hydrogen sulfide levels, supporting the involvement of reactive sulfur species in the cellular response to DNA damage. Proteome-wide analyses revealed that cysteine oxidative modifications preferentially target proteins involved in central metabolism, nucleotide biosynthesis, and genome maintenance. Consistent with these observations, MMS-induced genotoxic stress promotes metabolic adaptation characterized by increased mitochondrial respiration, elevated ATP production, and mitochondrial morphological remodeling, linking bioenergetic adaptation to redox regulation. Importantly, perturbation of intracellular redox balance using N-acetylcysteine compromises survival under DNA-damaging conditions, supporting a functional role for redox signaling during the DDR. Finally, MMS treatment also induces protein persulfidation in mammalian cells. Moreover, exposure to etoposide, a mechanistically distinct genotoxic agent that induces DNA double-strand breaks through topoisomerase II inhibition, showed a similar trend, suggesting that protein persulfidation may not be restricted to alkylation-induced DNA damage. Together our findings identify protein persulfidation as a prominent component of the redox response to DNA damage and provide new insight into the functional interplay between mitochondrial metabolism, cysteine-based redox regulation, and genome maintenance.

Oxidation-Reduction↗

PubMed2026

Recovering membrane interaction kinetics of single molecules from 3D tracking data.

Interactions between cytosolic biomolecules and the bacterial inner membrane are fundamental to many cellular processes, yet directly measuring their binding kinetics in living cells remains challenging. Conventional 2D single-molecule tracking analyses can be insufficient, particularly when membrane association does not markedly alter the diffusion rate. Here, we present a method to recover membrane interaction kinetics from 3D single-molecule trajectories in rod-shaped bacteria. Using simulated 3D tracking data, we identify membrane-associated motion by quantifying how well short trajectory segments follow the circular curvature of the cell membrane. The resulting measure is further analyzed using a hidden Markov modeling framework, enabling robust discrimination between cytosolic and membrane-bound states and capturing the dynamics of state transitions without requiring diffusion-rate changes or direct colocalization with membrane markers. This work establishes a general framework for extracting membrane interaction kinetics from 3D single-molecule tracking data in live bacteria and highlights the value of realistic microscopy simulations for quantitative interpretation and systematic bias assessment.

Kinetics↗

PubMed2026

Deciphering CD8+ T cell exhaustion in human cancers through single-cell and spatial transcriptomics.

Exhausted CD8+ T cells (Tex) within the tumor microenvironment (TME) represents a critical barrier limiting anti-tumor immune responses. Tex cells are characterized by upregulated inhibitory immune checkpoint receptors, reduced cytotoxicity, and functional heterogeneity. Their genomic features and regulatory networks remain poorly defined, and only a minority of patients respond to immune checkpoint blockade (ICB) therapy. Single-cell RNA sequencing (scRNA-seq), through high-resolution transcriptomic profiling, has revealed diverse Tex subpopulations, identified subpopulation-specific marker genes and regulatory pathways. Spatial transcriptomics has further mapped the spatial distribution of Tex and their interaction networks with immune cells, tumor cells, and stromal cells, elucidating the impact of spatial heterogeneity on Tex functionality. Current studies indicate that the exhausted state of Tex is dynamic and modifiable, with functional differences among subpopulations closely associated with tumor progression and therapeutic response. However, the genomic characteristics, epigenetic regulation, and spatial interaction mechanisms of Tex require further exploration. This review summarizes recent advances in high-resolution omics technologies for precisely dissecting Tex heterogeneity, functional features, and interactions with other cells. It emphasizes the central value of optimizing Tex-targeted tumor immunotherapy strategies, providing theoretical foundations and directional guidance for developing more effective anti-tumor immunotherapies.

Humans↗

PubMed2026

Decoding tumor immune microenvironment heterogeneity by single-cell and spatial multi-omics: From immunotherapy resistance to translational biomarkers.

Immune checkpoint blockade has transformed cancer therapy, yet primary and acquired resistance remain major clinical challenges. Increasing evidence indicates that immunotherapy resistance cannot be fully explained by tumor-intrinsic alterations or conventional biomarkers such as PD-L1 expression, tumor mutational burden, or microsatellite instability. Instead, therapeutic response is shaped by the tumor immune microenvironment (TIME) as a heterogeneous, spatially organized, and dynamically evolving ecosystem. Single-cell omics has revealed diverse immune and stromal cell states, including progenitor and terminally exhausted T cells, suppressive myeloid programs, B-cell/TLS-associated immune-reactive states, and CAF-mediated exclusion phenotypes. Spatial transcriptomics, spatial proteomics, and imaging-based approaches further demonstrate that these cell states assemble into distinct immune niches, including immune-inflamed, T-cell-excluded, myeloid-suppressive, metabolic/hypoxic, and TLS-associated niches. These spatial ecosystems determine whether antitumor immune cells can access malignant cells, receive antigen-presenting support, or become restrained by stromal, vascular, metabolic, and myeloid barriers. In this review, we summarize how single-cell and spatial multi-omics redefine TIME heterogeneity in immunotherapy resistance, highlight ligand-receptor communication networks linking cell states to spatial immune dysfunction, and discuss emerging translational biomarkers for patient stratification. We further propose that future immunotherapy biomarkers should evolve from static single-marker assays toward longitudinal, spatially resolved, and interpretable multi-omics models that guide precision combination immunotherapy.

Humans↗

PubMed2026

Single-cell transcriptome revealed the aberrant keratinocytes activation in antigen presentation in atopic dermatitis.

BACKGROUND: Atopic dermatitis (AD), a common chronic inflammatory skin disease, has been extensively studied using single-cell genomics. However, keratinocytes, as key effector cells in AD, have underlying mechanisms remain incompletely understood and require further investigation. METHODS: We integrated single-cell transcriptomic data from skin tissues of healthy controls, chronic active AD patients, spontaneously healed AD (SHAD) patients, and an ovalbumin-induced AD mouse model. The study particularly emphasized the gene expression and cellular dynamics of keratinocytes across the different groups, as well as their interactions with immune cells. RESULTS: Compared to healthy controls, we observed significant changes in the keratinocyte transcriptome, cellular state, and keratinocyte-immune cell ligand-receptor interactions in AD skin, particularly the marked activation of genes involved in antigen processing and presentation. Interestingly, such gene activation was not observed in keratinocytes from the ovalbumin-induced AD mouse model, despite its phenotype closely resembling human AD. Furthermore, in SHAD, we identified a recovery of both the ligand-receptor interaction patterns and antigen processing and presentation genes, accompanied by a notable shift in the transcriptome. This involved a significant downregulation of genes related to cytoplasmic transcription and oxidative phosphorylation. Notably, this pattern was not observed in the self-healing mouse model following the removal of ovalbumin stimulation. CONCLUSION: Our results suggest that the persistent activation of antigen processing and presentation pathways in keratinocytes may be a key driver of chronic inflammation in AD. Therefore, redirecting anti-allergic therapeutic strategies from solely targeting immune cells to targeting of keratinocyte-mediated antigen presentation may offer a more effective approach. Furthermore, we raise concerns about the use of ovalbumin-induced mouse models to recapitulate human chronic AD, as the underlying mechanisms may differ significantly.

Dermatitis, Atopic↗