Abstract Genome-resolved virome analysis remains inaccessible for many samples, including those with clinical relevance, because viral nucleic acid recovered after enrichment is often too scarce to support de novo genome assembly. As a result, many analyses are limited to sparse read-level detection, which cannot recover divergent viruses, resolve strains, or interpret gene-level variation. Here, we developed Low Biomass Viral Sequencing (LBV-Seq), a workflow that couples low-input viral sample handling with modified primary template-directed amplification and short- or long-read sequencing to enable de novo reconstruction of DNA and RNA viral genomes from sub-femtogram to nanogram inputs. LBV-Seq reproducibly captures the same relative community composition, amplifies diverse viruses, and achieved broad genome coverage across nearly all targets regardless of viral genome structure, Baltimore class, abundance, or input mass. Short-read assemblies recovered near-complete genomes from femtogram-scale inputs. Long-read sequencing provided orthogonal support for genome structure, with PacBio HiFi reads spanning large portions of viral genomes and, in some cases, complete small viral genomes. Applied to virus-enriched human duodenal biopsy eluates, LBV-Seq provided proof-of-feasibility for recovering both bacteriophage and eukaryotic viral genomes from low-input biopsy-derived material. In the eluates tested, LBV-Seq recovered co-occurring Alphatorquevirus and Betatorquevirus genomes estimated to be present at roughly 10 copies/µL and at viral masses below 0.1 fg/µL. LBV-Seq enables genome-resolved virome analysis in samples previously limited to detection-based viromics, supporting viral discovery and strain-resolved analyses in settings where viral mass is low, including viruses enriched from human tissue biopsies.
Distinct senescent β-cell senotypes differentially drive islet aging and dysfunction
ABSTRACT Biological aging greatly impacts the body’s ability to handle glucose, and represents a major risk factor the development and progression of type 2 diabetes (T2D). Nonetheless, despite advances in cellular senescence research and the development of new senolytic therapies, the heterogeneity of cellular senescence in the human endocrine pancreas, as well as its roles in normal aging, remains to be elucidated at the single-cell level. Here, we performed single-cell–resolved spatial proteomics and transcriptomics on intact pancreas from 26 donors (ages 20–80) and multiplexed single-cell RNA sequencing and functional assays on dispersed islets from 14 donors (ages 34–69). We identify two discrete SnC subpopulations distinguished by relative expression of CDKN1A and CDKN2A. CDKN1A ⁺ senescent cells (SnCs) exhibit loss of β-cell identity, impaired insulin secretion, and a proinflammatory SASP associated with increased islet immune infiltration. In contrast, CDKN2A ⁺ SnCs retain transcriptional identity and functional competence, with lower inflammatory signaling. Together, these findings identify heterogeneous and functionally divergent senotypes in the human pancreas, distinguishing an adaptive ( CDKN2A ⁺) from a maladaptive ( CDKN1A ⁺) senescence program, thus providing a mechanism-guided framework for senescence-targeted therapies in T2D.
Editorial: Mitochondrial dysfunction in cellular and molecular mechanisms of brain aging
ABSTRACT Background High-titer glutamic acid decarboxylase 65 (GAD65) antibodies are found in patients with GAD65 antibody-associated neurological disorders, including stiff-person syndrome (SPS), GAD65 cerebellar ataxia (CA), and GAD65 epilepsy. Given the intracellular localization of the antigenic target, a direct pathogenic role for GAD65 autoantibodies is unlikely. Instead, the autoantibody may be a biomarker for the existence of pathogenic anti-GAD65 autoreactive CD8 + T cells. Methods PBMC-derived dendritic cells (DCs) from 20 GAD65 antibody-positive patients with neurological manifestations (SPS, n=10; CA, n=7; epilepsy, n=3) and 15 healthy controls were pulsed with full-length GAD65 protein, full-length GAD67 protein, overlapping 15-mer peptide pools spanning GAD65 and GAD67, individual GAD65 15-mer peptides, or GAD65 9-mer peptides selected from predicted class I binding hotspots. T cell activation was quantified by flow cytometry-based activation-induced marker (AIM) assays using CD69 upregulation. Class I and class II HLA haplotypes were determined by high resolution typing. NetMHCpan v4.2c was used to generate residue-level peptide:HLA binding density maps across GAD65, and candidate 9-mers were validated for HLA binding by peptide:MHC monomer affinity testing. GAD65-peptide-HLA-restricted CD8 + T cells were identified by co-staining with two separately assembled tetramers carrying the same peptide:HLA complex on different fluorophores (APC and BV421), with double-positive events scored as antigen-specific. HLA-restricted cytotoxicity was measured by coculture of patient CD8 + T cells with GAD65-expressing HEK-293T cells reconstituted with defined HLA class I alleles using AAV-delivered Cre-dependent HLA-2A-eGFP cassettes. Results CD8 + T cells from GAD65 antibody-positive patients showed increased activation in response to DCs pulsed with full-length GAD65 relative to healthy controls (P=0.0157, Welch’s t-test), whereas responses to GAD67 did not differ significantly between groups. CD4 + T cells responded to both GAD65 (P=0.0004) and GAD67 (P=0.0051). Peptide pool screening of GAD65 identified discrete CD8 + and CD4 + immunogenic regions, with refinement using individual 15-mers localizing CD8 + activity to multiple subdomains within GAD65 (205-300) , GAD65 (316-435) , and GAD65 (447-520) . HLA class I haplotyping in 16 non-Hispanic White GAD65 + patients revealed enrichment of HLA-B*08:01 (3.0-fold) and HLA-B*40:01 (4.1-fold) relative to USA NMDP European Caucasian reference frequencies (both BH q < 0.05), with suggestive enrichment of HLA-C*03:04 (2.9-fold; q = 0.09). Additionally, 44% of patients carried the HLA-A*01:01, HLA-B*08:01, and HLA-C*07:01 8.1 ancestral haplotype, approximately four-fold higher than the expected population frequency. Dual-fluorophore tetramer staining identified CD8 + T cells in GAD65 + subjects that bound a subset of HLA-A*11:01- and HLA-B*08:01-restricted GAD65 9-mers, with the clearest disease-skewed signals localized to GAD65 (213-221) , GAD65 (257-265) , and GAD65 (529-537) . In an HLA-reconstituted target-cell killing assay, CD8 + T cells from an HLA-B*08:01-positive GAD65 + patient mediated antigen- and HLA-restricted depletion of GAD65-expressing HEK-293T cells, with HLA-restricted target loss also observed in single-donor experiments across additional HLA-A, -B, and -C contexts. Conclusions Patients with GAD65 antibody-associated neurological disorders harbor circulating CD8 + T cells that recognize discrete HLA class I-restricted GAD65 peptides and that are capable of cytotoxicity against GAD65-expressing HLA-matched target cells. We characterize the immunogenetic and cellular features of class I-restricted CD8 + T cell responses in GAD65 autoimmunity, including overrepresentation of the 8.1 ancestral haplotype, complementing the historical focus on antibodies and CD4 + T cell help, and we provide a panel of validated GAD65 peptide:HLA tetramers for prospective isolation, clonotypic analysis, and longitudinal monitoring of candidate pathogenic CD8 + T cell populations across the GAD65 antibody-associated neurological disease spectrum.
Multiple sclerosis (MS) is an immune-mediated chronic inflammatory and degenerative disease of the central nervous system (CNS). Typically occurring in young and middle-aged individuals, untreated MS can have high rates of disability and recurrence, thereby imposing a significant burden on the patient, their family, and society. Many factors are implicated in the etiology of MS, with the relationship between Epstein-Barr Virus (EBV) infection and the development of MS being the subject of extensive research recently. When the human body experiences a decline in immune function, it may trigger reactivation of EBV, and this reactivation is also believed to increase the risk of onset or relapse of MS. Currently, the phenomenon of cross-reactivity resulting from molecular mimicry following EBV infection (including reactivation status) is theorized as a contributing etiology. EBV-mediated abnormalities in T cells and B cells also play a key role in the development of MS. However, the underlying mechanisms have not been thoroughly understood. Meanwhile, the limited availability of effective treatment options for MS, in particular MS progression, underscores the urgent need for novel therapeutic strategies. Here, we discuss the pathophysiological mechanisms underlying MS, specifically emphasizing the relationship between EBV infection and the disease pathology. Furthermore, we introduced relevant pharmacological targets in order to propose a broader range of therapeutic alternatives for individuals diagnosed with MS.
Editorial: Neuroinflammation in postoperative cognitive dysfunction and related disorders
Study objective: To characterize physiologic autonomic dysfunction in humans after chronic spinal cord injury (SCI) relative to uninjured controls and to identify autonomic correlates to neuroimmune deficits. Hypothesis: Individuals with greater autonomic dysfunction after SCI will have more pronounced immune dysfunction, which will be further influenced by sympathetically mediated increases in catecholamine levels. Methodology: Both uninjured controls and individuals with SCI completed a battery of autonomic physiology tests aimed at characterizing preservation of supralesional/sublesional sympathetic activation and global sympathetic inhibition. The autonomic testing battery included 3-minute hand and foot cold pressor tests, 3 Valsalva maneuvers with goal expiratory pressure of 30 mmHg, a novel bladder pressor test (5 minutes of sustained bladder pressure at 35 cmH20 with room temperature sterile water infusion), paced breathing at 0.25 Hz for heart rate/blood pressure variability, and successive doses of bolus intravenous phenylephrine (Oxford technique). A subset of individuals in both cohorts had baseline and cold pressor stressed levels of catecholamines/cortisol drawn and immunologic assessments. Peripheral blood mononuclear cells were extracted from this baseline sample and assessed with flow cytometry for cellular exhaustion markers (CD69, PD-1, TIGIT, TIM-3). Antigen recall response, with/without primed exposure of catecholamines was also completed to identify how sympathetic activation variably impacted functional immune performance with exposure to viral peptides. Data: n=35 uninjured controls; n=29 individuals with SCI Summary of Results: When compared to uninjured controls, individuals with SCI demonstrated significant autonomic dysfunction in all three domains, with decreased supralesional sympathetic activation (Valsalva pressure recovery time, p< 0.0001), abnormal sublesional sympathetic activation (increased bradycardia, p< 0.0001), and impaired sympathetic inhibition (larger dose/body-weight adjusted increase in mean arterial pressure, p=0.0006). As expected, autonomic dysfunction in those with SCI existed on a continuum, with some having largely normal autonomic regulation and others exhibiting profound deficits. Principal component analysis confirmed these three domains as the primary drivers of variability. Cellular exhaustion markers were increased in those with SCI, with positive correlation (R2=0.42) between degree of global autonomic dysfunction (Z-score over 2.0) and CD3+ CD8+ T-cell TIM-3 immunologic exhaustion markers. Antigen recall response was impaired in those with SCI and autonomic dysfunction on physiologic testing, with pronounced decrement in response when catecholamines were added (mean 57% of response lost in CD69 T-cells to Epstein-Barr virus antigen exposure, 53% lost to Flu antigen). Conclusions: In humans with SCI, early evidence supports that individuals have greater autonomic dysfunction and that this is correlated to increased immunologic deficits. Funding Sources: NIH K23HD102663, R01NS115126 This abstract was presented at the American Physiology Summit 2026 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.
Evaluation of Regorafenib in Newly Diagnosed and Recurrent Glioblastoma: GBM AGILE Phase II/III Bayesian Randomized Platform Trial
PURPOSE GBM AGILE (ClinicalTrials.gov identifier: NCT03970447 ) is a phase II/III Bayesian adaptive platform registration trial testing multiple arms against a common control; the primary end point is overall survival (OS). Regorafenib, a multikinase inhibitor, showed OS benefit in recurrent (RD) glioblastoma in the phase II REGOMA trial and entered GBM AGILE as the first investigational arm. METHODS Patient subtypes included in the regorafenib arm of GBM AGILE were newly diagnosed unmethylated (NDU) and RD glioblastoma. Prospective defined sets of subtypes, or arm signatures, were NDU, RD, and all (NDU + RD). As the first investigational arm in GBM AGILE, regorafenib was equally randomized to the control arm. Treatment in the control arm is temozolomide + radiotherapy (in newly diagnosed) or lomustine (in RD). Efficacy was assessed by OS hazard ratio (HR), arm/control, and demonstrated when the Bayesian probability of benefit (HR <1.00) was ≥98%. Analysis was performed monthly for limited efficacy, which occurs when the Bayesian predictive power is <25% for all signatures, and determines stopping enrollment. Follow-up continued for 12 months after accrual stopped. RESULTS When the predictive power was <25% in all predefined signatures for regorafenib, accrual stopped for limited efficacy. The final analysis did not demonstrate OS improvement in the regorafenib arm in RD nor NDU glioblastoma. Median HRs were 1.05 (NDU), 1.07 (RD), and 1.07 (all) with final probabilities of benefit (HR <1.00) of 0.421 (NDU), 0.312 (RD), and 0.296 (all). Regorafenib was associated with increased toxicity relative to control. CONCLUSION GBM AGILE did not show superiority of regorafenib over control in RD (lomustine) or NDU (temozolomide + radiotherapy) glioblastoma, yet caused increased toxicities. Regorafenib has been removed from National Comprehensive Cancer Network guidelines as a treatment option for RD.