Biology subjects

Wu, M.

Publications and source records attributed to Wu, M..

At least 19 recordsLinked to original sources

bioRxiv2026

Digital molecular kinetics enabled by large-scale nanopore arrays for multidimensional biophysical profiling

While widely used, traditional technologies like surface plasmon resonance (SPR) are limited by narrow temporal windows (transient capture and baseline drift), dynamic heterogeneity, and poor physiological temperature performance. Meanwhile, early nanopore approaches are often constrained by limited throughput and heavy reliance on customized modification schemes. Here, we present a digital molecular kinetics (DMK) platform based on large-scale nanopore arrays. By introducing a universal coupling and probe reporting system, DMK achieves broad versatility across diverse molecular pairs, including proteins, peptides, small molecules, DNA, and polymerase complexes. In addition to accurately recovering classical SPR association and dissociation rate constants, by harnessing massive single-molecule event analysis, DMK breaks traditional performance boundaries: it facilitates robust thermodynamic-kinetic profiling across a wide temperature range, resolves distinct conformations in heterogeneous samples, enables ultra-low dissociation rate quantification via maximum likelihood estimation, and reveals energy wells via voltage gradients for binding analysis against environmental perturbations. Furthermore, DMK enables the capture of rapid binding events missed by SPR, offering a new perspective on molecular interaction complexity. This platform offers an effective alternative and upgrade to SPR, opening a digital paradigm for complex molecular analysis and drug discovery.

biophysics↗

bioRxiv2026

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↗

bioRxiv2026

Long-form hibernation-promoting factor coordinates 100S assembly and translational repression

Ribosome hibernation mediated by long-form hibernation-promoting factor (HPF) requires coordination of ribosome dimerization and translational repression, but how these functions are integrated remains unclear. Here, we present cryo-EM structures of native 100S from a deep-sea Bacillus isolate, revealing a conformationally heterogeneous 100S population. Beyond the established roles of the HPF N-terminal domain (NTD) in decoding-center occlusion and the C-terminal domain (CTD) in dimerization, our analyses reveal additional contributions from the Linker and a charged CTD surface near the 16S rRNA 3' terminus containing the anti-Shine-Dalgarno (aSD) sequence. Linker substitutions differentially affect translational repression while retaining 100S formation, with distinct effects of the two Linker segments. Mutation of the charged CTD surface enhances translational repression while retaining robust 100S formation, suggesting an additional role beyond CTD-mediated ribosome dimerization. Functional analyses in an E. coli cell-free translation system further show that the inhibitory activity of individual HPF regions varies with translational context. Together, these findings support a modular model in which the NTD, Linker, and CTD make distinct but interconnected contributions to 100S assembly and translational repression.

biochemistry↗

bioRxiv2026

Resource-access breadth marks protective strains against toxigenic Clostridioides difficile

Antibiotic disruption of gut microbiota creates opportunities for toxigenic Clostridioides difficile. One strategy is to occupy this niche with a non-toxigenic or weakly virulent strain, but even strains that cause little disease may fail to compete during pathogen challenge. We screened 21 sequence type 1 (ST1) isolates for their ability to protect mice co-colonized with toxigenic VPI10463, separating disease potential from protection. Some strains, such as ST1-75, caused little disease and protected, whereas others, such as ST1-68, caused little disease but failed to protect. Metabolomics showed that ST1-75 depleted more proline than ST1-68, whereas another protective strain, ST1-6, had a different metabolic profile; both protective strains nevertheless responded to many substrates. Substrate-utilization profiling revealed that protection across the 21 isolates correlated with amino-acid overlap with VPI10463, but not overall nutrient overlap or shared genome-encoded protein families. Relative amino-acid access explained variation beyond mono-colonization disease potential, and a consumer-resource model showed how nutrient overlap together with additional resource access can support persistence during competition. Additional experiments support that ST1-mediated protection occurs even in the absence of mature B and T cells. These findings distinguish low disease potential from protection, link protection to strain competition, and identify relative resource access as an informative phenotype for prioritizing strains for biotherapeutic testing.

microbiology↗

bioRxiv2026

Systemic tumor-cell reprogramming converts solid tumors into in situ biofactories for immunotherapy

A central challenge in oncology is delivering potent drugs to tumors without harming healthy tissues. We therefore asked whether tumor cells themselves could be genetically programmed to produce therapeutic molecules directly within the tumor. We present LENTRA (LENtiviral Tumor-Reprogramming Activator), an antigen-targeted lentiviral platform that enables selective transduction and genetic modification of tumor cells in vivo. Following intravenous administration, LENTRA achieves tumor restricted expression of immune checkpoint inhibitors, cytokines, or therapeutic enzymes in multiple murine solid tumor models. Local production of anti CTLA 4 or IL 12 triggered potent antitumor responses while avoiding systemic toxicities. Tumor restricted secretion of sialidase enhanced dendritic cell and T cell infiltration, and reprogrammed tumor associated macrophages toward an immunostimulatory phenotype, resulting in tumor regression and durable immune memory, including in tumors with heterogeneous antigen expression. In patient derived tumor explants, LENTRA mediated efficient transduction, immune remodeling, and reduced tumor viability. By engineering tumors to produce therapeutic proteins, LENTRA converts resistant tumors into autonomous therapeutic sources and active immune hubs, achieving local TME reprogramming and systemic antitumor immunity with an improved safety profile.

cancer biology↗

bioRxiv2026

Rethinking the Benign Nature of Class II Lupus Nephritis

Introduction: Class II lupus nephritis (LN) is considered clinically benign, yet up to 50% of patients progress to more severe disease and no molecular characterization exists. We aimed to define the single-cell landscape of Class II LN and identify cellular and transcriptional features associated with kidney outcome. Methods: We performed single-cell RNA sequencing on kidney biopsies from fifteen Class II LN patients (eight de novo, seven regressed from prior proliferative or membranous disease) and six healthy controls, integrated with 155 LN and 30 healthy-control samples from the Accelerating Medicines Partnership in SLE spanning proliferative, membranous, and mixed LN. Findings were correlated with 52-week renal response and supported by urinary proteomics. Results: Despite histologically minimal changes, Class II LN exhibited marked immune cell expansion comparable to proliferative and membranous LN, including CCL3+ CCL4+ intermediate monocytes producing TNF, FOLR2+ SIGLEC1+ macrophages producing TGF{beta} and PDGF, and CD69+ CD8+ effector memory T cells producing IFN{gamma}. Fibroblasts and myofibroblasts were significantly expanded and displayed divergent transcriptional programs: pro-fibrotic and inflammatory myofibroblast modules were associated with worse 52-week outcomes, while interferon-responsive and matrix-remodeling fibroblast programs were associated with improvement. Pathogenic and protective fibroblast populations received overlapping immune-derived signals, suggesting that fibroblast transcriptional state, rather than the identity of incoming signals, shapes the stromal response. Baseline chronicity index captured this stromal heterogeneity and was the clinical parameter most associated with outcome. Urinary proteomics aligned Class II with proliferative rather than membranous disease. Conclusions: Class II LN harbors substantial molecular activity not captured by routine histology. Fibroblast transcriptional programs and baseline chronicity index are candidate correlates of kidney outcome that warrant validation in larger, prospectively followed cohorts.

genomics↗

bioRxiv2026

Spatially resolved gene expression and tumour-microenvironment interactions across malignant transformation in IDH-mutant glioma

Isocitrate dehydrogenase (IDH)-mutant gliomas represent most lower-grade diffuse gliomas in young adults. Although IDH-mutant gliomas initially behave indolently relative to IDH-wildtype counterparts, they undergo inevitable malignant transformation. The mechanisms driving this progression remain poorly defined. We analyzed a unique longitudinal cohort of two patients with IDH-mutant diffuse gliomas, each with matched WHO grade 2, 3, and 4 tumours. Spatial transcriptomics (NanoString GeoMx and 10X Visium), combined with differential expression, spatially variable gene analysis, and gene ontology enrichment, were used to define transcriptional programs underlying progression. Unexpectedly, across both patients, higher-grade tumours demonstrated reduced proliferation at the infiltrative margin as measured by Ki67. Spatial transcriptomic analysis identified an enrichment of invasion-associated genes associated with increasing tumour grade. In an independent bulk RNA-seq cohort, expression of this spatially derived program did not outperform grade-only PFS or OS analysis. These observations underscore the need to develop new metrics that account for spatial evolution that occurs across progression, but escapes detection in bulk analyses and provide the rationale for prioritizing migration-, cytoskeletal- and stress-associated programs for further investigation.

cancer biology↗

bioRxiv2026

Ileal Gpbar1 gates depressive phenotypes via gut to brain "vagal-NTS-PVN"GABAergic axis

Depression represents a typical mental condition, yet whether intestinal metabolic signals drive central neural circuits remains unclear. Here we identify ileal enteric neuronal Gpbar1 as a previously unrecognized peripheral node that coordinates gut-to-brain communication to prevent depression-like behavior through a vagus-dependent, nucleus tractus solitaries (NTS)-paraventricular nucleus (PVN) signaling axis. The enteric plexus Gpbar1 is predominantly expressed on a subpopulation of GAD1-positive GABAergic neurons. Chronic restraint stress suppresses Gpbar1 expression, triggers glycolytic reprogramming and mitochondrial distress in both ileum and hypothalamus. Oral Gpbar1 agonism with INT-777 reverses hypothalamic HK2/TOM20 alterations and behavioral abnormalities by enhanced ileal mTOR/HIF-1 alpah signaling and glycolysis-related metabolite shifts, an effect specifically abolished by subdiaphragmatic vagotomy or chemogenetic silencing of PVN GABAergic neurons. Our findings establish ileal Gpbar1 as a gut-derived metabolic sensor that engages a defined vagal-brainstem-hypothalamic inhibitory circuit to regulate depressive phenotypes, shifting the roadmap from brain-centered to gut-initiated antidepressant mechanisms and unveiling a compelling peripheral therapeutic strategy that bypasses intractable central brain-directed intervention.

neuroscience↗

bioRxiv2026

Physiological folate levels constrain nucleotide synthesis and increase dependence on nucleotide salvage

Proliferating cells must acquire nucleotides to support DNA replication, yet how cells meet these nucleotide demands for proliferation under physiological conditions remains understudied. Here, we investigated how physiological nutrient availability shapes nucleotide acquisition strategies in a mouse model of B-cell acute lymphoblastic leukemia (B-ALL). To assess how environmental nutrients impact nucleotide metabolism, we formulated a mouse plasma-like medium (MPM) that reproduces the circulating metabolite composition of plasma from mice with B-ALL and assessed how this influenced nucleotide metabolism relative to standard culture conditions, where nucleotide acquisition has historically been studied. We find that leukemia cells cultured in MPM acquire nucleotides through salvage pathways, and that select nucleotide salvage pathways are required for proliferation under physiological conditions. Of note, this dependency on nucleotide salvage in plasma-like conditions was not caused by precursor metabolite limitation for de novo synthesis. Instead, we found that physiological folate levels are insufficient to support deoxynucleotide triphosphate (dNTP) synthesis for genome replication, leading to DNA replication stress and impaired proliferation when nucleotide salvage is disrupted. Consistently, dietary folate restriction exacerbates the impaired leukemia progression phenotype of nucleotide salvage-deficient B-ALL cells. Together, these findings demonstrate that access to folates is an endogenous limitation for nucleotide synthesis in plasma-like nutrient conditions, increasing the relevance of nucleotide salvage pathways for leukemia progression. More broadly, this work highlights how micronutrient abundance can influence metabolic dependencies and reveals that folate levels shape nucleotide metabolism under physiological conditions.

cancer biology↗

bioRxiv2026

Dark proteome ensemble superposition gating calibrates biosynthesis of antiviral cocktail

Intrinsically disordered regions (IDRs)-the proteome dark matter-confer dynamic adaptability upon rigid protein scaffolds. How IDRs and their adjacent folded domain (context) modulate enzyme substrate promiscuity and calibrate host-specific immune outputs remains unknown. Addressing this knowledge gap has substantial economic and industrial value in pharmaceutical drug discovery, biotechnological applications, and synthetic biology. Here, we report that the widely studied and conserved radical S-adenosylmethionine enzyme of intrinsic immunity, viperin, has a C-terminal IDR that calibrates synthesis of host-specific antiviral cocktails. We show that a C-terminal tripeptide and its context shape the IDR conformational space (ensemble), keeping active-site entry in a superposition of open and closed states. Consequently, transplanting the rat enzyme C-terminal tripeptide context into its human orthologue alters the antiviral cocktail output. These results revise the prevailing model that vertebrate viperins with identical active-site pockets generate the same antiviral output, establish a new framework in host-specific antiviral responses, and inform IDRs biotechnological applications.

biochemistry↗

bioRxiv2026

Dissecting the TMEM132A-EGFR Dependency to Unlock Translational Therapeutic Opportunities for Pan-Solid Tumor

Solid tumors remain refractory to conventional treatments, yet cell surface proteins, by virtue of their extracellular accessibility and critical roles in tumor signaling, represent an attractive class of targets for precision-targeted therapy. Here, we report that TMEM132A is an essential and previously unrecognized pan-cancer target. TMEM132A interacts directly with EGFR and stabilizes its expression, thereby tethering EGFR at the plasma membrane and sustaining constitutive activation of lipid synthesis. Mechanistically, the TMEM132A-EGFR axis promotes lipogenesis by facilitating SREBP nuclear translocation, which in turn upregulates ACLY and ACSS2 expression to drive acetyl-CoA production and downstream lipid biosynthesis, ultimately disrupting lipid droplet homeostasis. To therapeutically target this axis, we developed a nanobody, LFNanoT132A#3, which effectively blocks the TMEM132A-EGFR interaction, abrogates downstream signaling activation, and potently inhibits proliferation across multiple solid tumor types. Notably, LFNanoT132A also exerts robust antitumor activity against H1975 xenografts, a model resistant to first- and second- generation EGFR inhibitors, underscoring its potential to overcome conventional drug resistance. Our findings establish TMEM132A#3 as a critical node in membrane-tethered oncogenic signaling and metabolic rewiring, and position LFNanoT132A#3 as a promising therapeutic candidate for precision cancer therapy.

cancer biology↗

bioRxiv2026

Immunometabolic Reprogramming by Thyroid-Stimulating Antibodies Drives Orbital Adipogenesis via Histone Lactylation in Thyroid Eye Disease

Thyroid eye disease (TED) is conventionally viewed as an autoimmune inflammatory disorder. However, the metabolic determinants driving orbital tissue remodeling remain largely undefined. Here, we uncover a paradigm-shifting mechanism whereby thyroid-stimulating antibodies (TSAbs) instigate profound metabolic reprogramming in orbital fibroblasts (OFs), driving a switch toward glycolysis and markedly elevating lactate production via the CREB/LDHA axis. Critically, we demonstrate that this TSAbs-induced metabolic perturbation is not a mere byproduct but the principal driver of pathology. Mechanistically, lactate functions as a signaling metabolite that directly potentiates adipogenesis via histone lactylation-dependent transcriptional activation of the master adipogenic regulators PPAR{gamma} and C/EBP. Collectively, our findings underscore metabolic reprogramming as a central pathogenic mechanism in TED, whereby autoimmune cues drive disease progression through metabolic-epigenetic crosstalk. This work substantiates the paradigm of TED as an immune- metabolic disorder.

immunology↗

bioRxiv2026

Human cornea harbors tissue-resident memory T cells shaped by systemic immune activation, age and biological sex

The cornea is classically regarded as an immune-privileged tissue. However, recent studies have identified T cells in the healthy human cornea that are absent in specific pathogen-free (SPF) mice. The identity of these T cells, the systemic cues that drive their establishment, and the molecular mechanisms governing their corneal homing remain unknown. Here, we combine multimodal human data with tractable murine models to characterize the cellular basis of corneal immune surveillance. Immunofluorescence staining and confocal imaging of clinically non-inflamed human donor tissues revealed CD3 T cells within the corneal epithelium. Flow cytometry revealed that these cells were predominantly CD8, with a tissue-resident memory T (TRM) cell phenotype. In vivo confocal microscopy demonstrated that corneal T cell abundance increased with age, particularly in males, suggesting that accumulation is shaped by cumulative systemic immune experience. Whereas young SPF mice were devoid of corneal T cells, infection with pathogens that do not typically target the cornea induced long-lived TRM-like CD8 T cells in the cornea. We identified CXCR6 as required for efficient T cell recruitment to the cornea of viral-infected mice. Together, our human and murine data support a model in which systemic immune history, age and biological sex influence local immune surveillance at the human ocular surface.

immunology↗

bioRxiv2026

WWOX contributes to DNA damage, but not somatic instability in Huntington s disease

Huntingtons disease (HD), caused by a CAG repeat expansion in the huntingtin (HTT) gene, is characterized by progressive neurodegeneration and accumulation of DNA damage with multiple disease-modifier genes involved in DNA repair pathways. Previous studies have implicated ataxia telangiectasia mutated (ATM) signaling in the regulation of genomic stability and DNA damage repair (DDR) pathways in HD. ATM has also been linked to the WW domain-containing oxidoreductase (WWOX), a protein involved in DNA repair and maintenance of genomic stability, through the E3 ubiquitin ligase ITCH. However, whether this signaling pathway contributes to HD pathogenesis remains unknown. Here, we investigated the role of ATM-ITCH-WWOX signaling in HD. Our results revealed no significant alterations in total ATM, phosphorylated ATM (pATM-S1981), or ITCH in HD post-mortem prefrontal cortex (PFC) compared to controls. Although treatment of human neuroblastoma SH-SY5Y cells with HD PFC lysates did not alter pATM-S1981 levels, it increased histone H2AX phosphorylation at S139 ({gamma}-H2AX), a marker of DNA double-strand breaks. This finding suggested the presence of persistent DNA damage signaling independent of canonical ATM activation. Conversely, WWOX levels were increased in both HD PFC and HD embryonic stem cell-derived cortical neurons. Additionally, treatment of SH-SY5Y cells with recombinant human WWOX protein or WWOX overexpression increased {gamma}-H2AX levels, supporting a role for WWOX in promoting DNA damage. To determine whether WWOX contributed to DNA damage in HD, SH-SY5Y cells were treated with HD PFC lysates that were depleted of WWOX. Immuno-depletion of WWOX reduced the ability of HD PFC lysates to increase {gamma}-H2AX, suggesting that WWOX contributes to DNA damage in HD. Finally, overexpression of WWOX in RPE1-AAVS1-CAG115 cells did not affect somatic CAG repeat instability, despite persistent increases in {gamma}-H2AX levels. Collectively, our findings identify WWOX as a contributor to DNA damage in HD, acting independently of the ATM pathway.

neuroscience↗

bioRxiv2026

Among-population variation in the threespine stickleback ( Gasterosteus aculeatus ) liver metabolome: effects of ancestry and environment

Untargeted metabolomics offers a powerful lens for quantifying high-dimensional phenotypic variation within and among species in nature, but has yet to be widely adopted in evolutionary ecology. Some important initial questions are whether metabolome composition differs among populations, and to what extent such variation is genetic or plastic. Here, we use untargeted liquid chromatography tandem mass spectrometry to characterize the relative abundance of 5,939 molecular features of the threespine stickleback (Gasterosteus aculeatus) liver metabolome. Native lake populations differ in metabolome composition, reflecting effects of sex, size, geography, and population ecotype (benthic versus limnetic). Stickleback from these lakes were translocated to found new populations in nine recently fishless lakes, permuting fish ecotypes across benthic and limnetic lake habitats. Several generations later, metabolomes in these experimental populations reflect effects both of their genetic ancestry (e.g., taurocholic acid, a cholane steroid bile acid, was elevated in limnetic-ancestries), as well as their present habitat (e.g., acylcarnitines). Additionally, ecotypes transplanted into a habitat to which they were maladapted exhibited a distinctive metabolomic profile. We conclude that stickleback exhibit both heritable and plastic among-population differences in liver metabolome, which could represent an important phenotypic basis of rapid evolution, population divergence, and perhaps local adaptation.

Molecular Biology↗

bioRxiv2026

Systematic Profiling and Functional Characterization of Alternative Splicing in C. elegans Olfactory Learning

Alternative splicing (AS) is prevalent in neuronal gene expression. However, its function in learning has not been systematically characterized. Here, by profiling pan-neuronal translatome changes during a C. elegans learning paradigm, we show that AS remodels expression of neuronal genes with critical function in learning at the genome-wide scale. Intriguingly, AS operates on a functionally distinct gene set from those showing transcript abundance changes, serving as a separate regulatory layer in response to experience. Specifically, a neuronally enriched worm ortholog of a mitochondrial DNA helicase twnk-1 displays significant learning-associated AS changes, with both isoform types acting in a pair of sensory neurons to regulate learning with distinct functions. AS of twnk-1 modulates a cell-nonautonomous signal from neuronal mitochondria to peripheral tissues to regulate physiological states critical for learning. These results establish AS as a systematic regulator of learning and mechanistically reveal how AS shapes physiological states to facilitate learning.

neuroscience↗

bioRxiv2026

Cross-Modal Benchmarking of Acoustic Prosody and Ventral Striatal BOLD for Depression-Related Anhedonia Classification: A Pre-Registered Study with the ClinicalWhisper Pipeline

Can computational analysis of a brief voice recording classify depression-related anhedonia as effectively as task-based fMRI? We address this question through a pre-registered cross-modal benchmarking study (osf.io/bsvrj) that evaluates two independent classification pipelines against depression-related anhedonia operationalized via self-report. Anhedonia-- the diminished capacity to experience pleasure or motivation to pursue rewards--is a transdiagnostic marker of reward-system dysfunction that predicts treatment resistance in major depressive disorder, yet current assessment requires either expensive functional neuroimaging or subjective self-report scales, neither of which scales to routine screening. We benchmarked two independent classification pipelines: Stream A extracted 88 acoustic prosody features from DAIC-WOZ clinical interviews (n = 142) using the ClinicalWhisper pipeline (Whisper Large-v3, pyannote diarization, OpenSMILE eGeMAPS v02); Stream B extracted nucleus accumbens BOLD activation during a reward task from the UCLA ds000030 dataset (n = 272). Three classifiers (logistic regression, random forest, gradient-boosted trees) were evaluated under stratified 5-fold cross-validation with fixed, pre-registered hyperparameters. Stream A achieved a best AUC-ROC of 0.63 (random forest; permutation p = .049), confirming H1 that acoustic prosody classifies PHQ-8-defined anhedonia above chance at = .05 (uncorrected), though this result does not survive Bonferroni correction for three classifiers (/3 = .017). Bootstrap analysis of {Delta}AUC confirmed non-inferiority relative to Stream B (H2: 95% CI lower bound > -0.10). However, Stream B itself did not achieve above-chance classification (p = .057), so this non-inferiority finding reflects comparable, modest performance across both modalities rather than equivalence to a validated neural biomarker. Pitch variability features (F0) ranked among the top 5 predictors by SHAP value in the gradient-boosted trees model (H3: partially supported). An exploratory combined model (eGeMAPS + recurrence quantification analysis) reached AUC = 0.65 (GBT; p = .032), though this lift was not statistically significant by DeLong test (z = -0.44, p = .66). These results provide initial evidence that vocal prosody, acquired through a standardized, open-source pipeline, carries depression-related information comparable to fMRI-derived ventral striatal activation for binary classification. However, neither streams operationalization isolates anhedonia from general depressive symptomatology, and the cross-modal design compares different constructs across different cohorts. We refer to the classification target throughout as the "anhedonia composite" to acknowledge that PHQ-8 Items 1+2 conflate anhedonia with dysphoria. We discuss these constraints and their implications for the causal framework motivating this work.

neuroscience↗

bioRxiv2026

SARS-CoV-2 BA.3.2.2 is more evasive of neutralization by sera from young children

Dominant SARS-CoV-2 variants have most prominently displayed greater evasion of serum neutralizing antibodies than predecessor strains. BA.3.2, a descendant of Omicron BA.3, carrying 43 additional spike mutations, emerged in 2024, and over the last several months its subvariant BA.3.2.2 has slowly increased in prevalence globally. BA.3.2.2 continues to circulate at lower frequency than the genetically and antigenically distant dominant JN.1 subvariants NB.1.8.1 and XFG. However, concerningly, epidemiologic analyses have suggested that a larger proportion of COVID-19 cases in children are caused by BA.3.2.2 compared to adults, raising the possibility that susceptibility to BA.3.2.2 differs across age groups. Since immune imprinting shapes variant-specific anti-SARS-CoV-2 antibody profiles and children born after 2021 primarily were first exposed to Omicron subvariants, we hypothesized that young children may have lower circulating neutralizing antibody titers against BA.3.2.2 than adults. Using pseudovirus neutralization assays, we measured titers against BA.3.2.2 and other SARS-CoV-2 variants in serum or plasma samples from a total of 36 adults ([≥]18 years old), school-age children (3-10 years old), and infants/toddlers (6-28 months old) in the US. We found that both cohorts of children had lower geometric mean titers against BA.3.2.2 than adults, even though all tested age groups had similar titers against dominant strains NB.1.8.1 and XFG. Together, these findings suggest that susceptibility to emerging SARS-CoV-2 variants may diverge across age groups, perhaps as a result of their different exposure histories. Furthermore, these results highlight the importance of SARS-CoV-2 surveillance and the monitoring of immunity against viral variants across age ranges.

microbiology↗