Biology subjects

Altman, M.

Publications and source records attributed to Altman, M..

7 recordsLinked to original sources

bioRxiv2026

Association of CRP and synovial fluid HMGB1 with Pain in Oligoarticular and Polyarticular Juvenile Idiopathic Arthritis: a cross-sectional study

BackgroundPain is one of the most prevalent and distressing symptoms in juvenile idiopathic arthritis (JIA) and often persists despite treatment. Damage-associated molecular patterns (DAMPs), such as high mobility group box 1 (HMGB1) and S100A8/A9, have been implicated in inflammatory activation and nociceptive sensitization, but their associations with pain are not fully characterized in JIA. MethodsPlasma and paired synovial fluid (SF) samples were obtained from patients with oligoarticular and polyarticular JIA from the Juvenile Arthritis Biobank (JABBA). A discovery cohort (n = 79) was used to investigate associations between biomarkers and pain, and these associations were subsequently examined in a validation cohort (n = 38). Levels of HMGB1, S100A8/A9, IL-6, IL-8, C2C, and TRAP5b were measured using ELISA. Associations between biomarkers and patient-reported pain scores were assessed using multivariable linear regression analyses. ResultsPlasma and SF levels of most biomarkers did not show significant correlations, except for TRAP5b, which demonstrated a moderate correlation. In the discovery cohort, as multivariable linear regression analyses, both CRP and SF HMGB1 ({beta} = 1.14, 95% CI: 0.21-2.08; {beta} = 1.54, 95% CI: 0.06-3.01 respectively in fully adjusted model) were independently associated with higher pain scores. SF S100A8/A9 ({beta} = 1.00, 95% CI: 0.10-1.89) was additionally associated with pain in fully adjusted models. Sensitivity analyses confirmed the robustness of these findings. These associations were further supported in the validation cohort. ConclusionsPain in JIA is associated with both systemic CRP and local alarmin markers, with SF HMGB1 showing a particularly robust association. These findings highlight the importance of local joint HMGB1 in pain mechanisms and suggest a potential role for DAMP-mediated pathways in persistent pain in JIA.

immunology↗

bioRxiv2026

Hippocampal Neuroinflammation and Altered Peripheral Neurobiological Protein Profile in Experimental Arthritis and Systemic Juvenile Idiopathic Arthritis

BackgroundChildren with juvenile idiopathic arthritis (JIA) are reported to exhibit increased rates of symptoms affecting emotional regulation and behavior. However, underlying biological mechanisms remain unclear. Neuroinflammation in the central nervous system (CNS) can be triggered by peripheral immune effects and may contribute to these observations. In this study, we aimed to investigate if neurobiological alterations are present in systemic JIA (sJIA), and if CNS neuroinflammation occurs during arthritis, and to explore the potential mechanisms involved. MethodsPlasma samples from patients with active sJIA (n = 16) and sex- and age-matched healthy controls (HCs, n = 16), together with paired samples from the same sJIA patients during inactive disease (n = 12), were analyzed using Olink proteomics to determine the peripheral neurobiological and inflammation protein profiles. Clinical data was retrieved from the Swedish Pediatric Rheumatology Register and medical charts. CNS Neuroinflammatory responses and underlying mechanisms were further explored through in vivo and in vitro experiments. FindingsActive sJIA patients exhibited altered neurobiological protein profiles compared with HCs. These alterations correlated with higher scores of pain and life impact in patients, suggesting that the altered profiles may reflect neurofunctional changes in the patients. Notably, the neurobiological protein profile remained altered even during the inactive phase of the disease. In chronic arthritic mice, microglial activation and impaired neurogenesis were observed in hippocampus, with no significant cortical changes. RNA-seq analysis implicated mitochondrial dysfunction and oxidative stress in mediating neuroinflammation during chronic arthritis in mice. Heme oxygenase 2 (HMOX2) was identified as a peripheral biomarker indicating hippocampal microglia activation. Combined neurobiological and inflammation profiling in sJIA patients implicated Interleukin-6 (IL-6) and Interleukin-18 (IL-18) as key drivers of hippocampal microglia activation during arthritis. InterpretationChronic arthritis is associated with neuroinflammation and altered neurobiological protein profiles in sJIA. HMOX2 emerges as a promising plasma biomarker of CNS changes. IL-6 and especially IL-18 are indicated as key drivers of neuroinflammatory processes. These findings offer insights for clinical monitoring and targeted therapies. FundingThis study was funded by grants from the Swedish Research Council and The Swedish Rheumatism Association. Research in contextO_ST_ABSEvidence before this studyC_ST_ABSChildren with juvenile idiopathic arthritis (JIA) have increased rates of emotional and behavioral disturbances compared with healthy peers. Systemic inflammation and chronic arthritis are suspected to affect the central nervous system, but biological mechanisms in systemic JIA (sJIA) are poorly understood. Added value of this studyIn this study, we demonstrate patients with sJIA have a distinct plasma neurobiological protein profile compared with healthy controls, which correlate with higher pain and life impact scores. In chronic arthritic mice, hippocampal microglial activation, impaired neurogenesis, and mitochondrial dysfunction with oxidative stress are presented. By combining patient and mouse data, we identify heme oxygenase 2 (HMOX2) as a candidate plasma biomarker of hippocampal neuroinflammation and implicate IL-6, and especially IL-18, as key mediators linking chronic arthritis to neurobiological changes. Implications of all the available evidenceThis study provides molecular evidence that neurobiological alterations in sJIA patients and supports incorporating neurobiological and neuropsychiatric monitoring into the clinical follow-up of children with sJIA. We highlight the mechanistic targets and measurable biomarkers (e.g. HMOX2) for future studies and trials aiming to modulate neuroinflammation in chronic arthritis. This study may inform the development of personalized treatment strategies, including IL-18-directed therapies, for patients at risk of neurological or psychosocial complications.

immunology↗

bioRxiv2025

Partial Inhibition of Viral Replication Machinery Enhances Recombination in Herpes Simplex Viruses

Herpes simplex viruses (HSV-1 and HSV-2) are widespread human pathogens, most commonly causing oral and genital lesions. These DNA viruses use recombination as a major driver of evolution. Intragenomic and intergenomic recombination events can be detected both in vivo and in vitro. As viral recombination is tightly linked to replication, deciphering mechanisms that specifically effect recombination remains a challenge. Here, we employed a triple-fluorescent color recombination assay to identify homology mediated and non-canonical recombination events between co-infecting HSV-1 strains. We developed a deep learning model that detects and classifies progeny plaques according to their colors. This setup enabled us to perturb the infection process using small molecule inhibitors targeting either viral or host proteins. We identified that inhibitors that reduce infectious viral progeny, increased viral homology mediated recombination. The antiviral drugs, including acyclovir, also increased recombination between HSV-1 and HSV-2 and aberrations in the progeny viral genomes. Taken together our results indicate that commonly used anti-herpes drugs increase intraspecies and interspecies recombination rates and genetic rearrangements. SignificanceHerpes simplex viruses cause significant morbidity in all human populations. Current therapies rely primarily on antivirals that target viral replication. Viral recombination plays a key role in replication and evolution of these dsDNA viruses. To better characterize the viral recombination process, we introduce a fluorescence-based HSV-1 recombination assay coupled with deep learning-based plaque classification, enabling high-throughput quantification of recombination rates. We found that clinically relevant moderate concentrations of commonly used antiviral replication inhibitors, enhance homology-mediated intraspecies recombination, HSV-1/HSV-2 interspecies recombination, as well as the accumulation of defective genomes. We conclude that partial inhibition of the herpes replication complex can promote viral diversification, with potential implications for HSV evolution and drug resistance.

microbiology↗

bioRxiv2025

Inflammation-profiling reveals activated pathways and biomarkers with predictive potential in oligoarticular JIA

ObjectiveWe set out to profile the immune mechanisms active in treatment-naive oligoarticular JIA (oJIA) to improve understanding of its immunopathogenesis, to identify potential biomarkers that can aid diagnosis, predictions and correlate with clinical disease parameters. MethodsUsing Olink proteomics (Inflammation Panel), we defined and compared the inflammation profiles of 38 plasma and 62 synovial fluid (SF) oJIA samples, 38 plasma samples from healthy age- and sex-matched controls (HC), 12 SF samples from non-arthritic controls and 26 SF samples from knee injury patients. Clinical data were retrieved from the Swedish Pediatric Rheumatology Quality Register. ResultsPlasma profiles of oJIA and HC were largely overlapping, with IL6 and MMP-1 upregulated in oJIA. In SF, 48 differentially expressed proteins (DEPs) were identified in oJIA, highlighting immune pathways like leukocyte migration, cell chemotaxis and adaptive immunity. Comparative analysis revealed 13 proteins specific to oJIA. Correlations were found between DEPs in oJIA SF and clinical parameters (cJADAS-71, pain, health impact score). Plasma IL6 and MMP-1 showed strong correlation with disease activity and pain, respectively. CXCL9, CXCL10 and CXCL11 were identified as potential predictive biomarkers for disease progression. ConclusionsThe overlap in plasma inflammation profiles of oJIA and HCs suggests local rather than systemic inflammation in oJIA, underlining the need for synovial fluid-based immunopathogenesis studies. Adaptive immune signatures in oJIA SF distinguished it from knee injury patients, offering potential for diagnostic application. Increased CXCL9, CXCL10 and CXCL11 in SF were associated with chronic disease progression and could serve as prognostic biomarkers and early treatment targets.

immunology↗

bioRxiv2024

Protein structure, a genetic encoding for glycosylation

Unlike DNA, RNA, and protein biosynthesis, dogma describes glycosylation as primarily determined by intrinsic cellular limitations, such as glycosyltransferase expression and precursor availability. However, this cannot explain the commonly-observed differences between glycans on the same protein. By examining site-specific glycosylation on diverse human proteins, we detected associations between protein structure and glycan structure, broadly generalizable to human-expressed glycoproteins. Through structural analysis of site-specific glycosylation data, we found protein-sequence and structural features consistently correlated with specific glycan features. To quantify these relationships, we present a new amino acid substitution matrix describing "glycoimpact", i.e., the association of primary protein structure and glycosylation. High-glycoimpact amino acids co-evolve with glycosites, and glycoimpact is high when estimates of amino acid conservation and variant pathogenicity diverge. We report thousands of disease variants near glycosites with high-glycoimpact, including several with known links to aberrant glycosylation (e.g., Oculocutaneous Albinism, Jakob-Creutzfeldt disease, Gerstmann-Straussler-Scheinker, and Gauchers Disease). Finally, glycoimpact quantification is validated by studying oligomannose-complex glycan ratios on HIV ENV, differential sialylation on IgG3 Fc, differential glycosylation on SARS-CoV-2 Spike, and fucose-modulated function of a tuberculosis monoclonal antibody. Finally, to test the causality of protein-glycan associations, we created 5 glycoimpact-designed novel Rituximab variants, 4 of which substantially changed glycoprofiles as predicted. In all, we report that site-specific glycan biosynthesis is influenced by underlying protein structure, enabling glycan structure prediction and genetic sequence-guided glycoengineering.

genetics↗

bioRxiv2020

TOLLIP promotes durable alveolar macrophage-mediated immunity during Mycobacterium tuberculosis infection by resolving cellular stress from lipids.

Relative deficiency of TOLLIP expression in monocytes is associated with increased tuberculosis (TB) susceptibility in genetic studies, despite antagonizing host innate immune pathways that control Mycobacterium tuberculosis (Mtb) infection. In this study, we investigated the mechanisms by which TOLLIP influences Mtb immunity. Tollip-/- mice developed worsened disease, consistent with prior genetic observations, and developed large numbers of foam cells. Selective TOLLIP deletion in alveolar macrophages (AM) was sufficient to induce lipid accumulation and increased Mtb persistence 28 days after infection, despite increased antimicrobial responses. We analyzed sorted, Mtb-infected Tollip-/- AM from mixed bone marrow chimeric mice to measure global gene expression 28 days post-infection. We found transcriptional profiles consistent with increased EIF2 signaling. Selective lipid administration to Tollip-/- macrophages induced lipid accumulation, and Mtb infection of lipid laden, Tollip-/- macrophages induced cellular stress and impaired Mtb control. EIF2 activation induced increased Mtb replication within macrophages, irrespective of TOLLIP expression, and EIF2 kinases were enriched in human caseous granulomas. Our findings define a critical checkpoint for TOLLIP to prevent lipid-induced EIF2 activation and demonstrate an important mechanism for EIF2 signaling to permit Mtb replication within macrophages.

immunology↗

bioRxiv2020

A modular framework for the development of targeted Covid-19 blood transcript profiling panels

Covid-19 morbidity and mortality are associated with a dysregulated immune response. Tools are needed to enhance existing immune profiling capabilities in affected patients. Here we aimed to develop an approach to support the design of focused blood transcriptome panels for profiling the immune response to SARS-CoV-2 infection. We designed a pool of candidates based on a pre-existing and well-characterized repertoire of blood transcriptional modules. Available Covid-19 blood transcriptome data was also used to guide this process. Further selection steps relied on expert curation. Additionally, we developed several custom web applications to support the evaluation of candidates. As a proof of principle, we designed three targeted blood transcript panels, each with a different translational connotation: therapeutic development relevance, SARS biology relevance and immunological relevance. Altogether the work presented here may contribute to the future expansion of immune profiling capabilities via targeted profiling of blood transcript abundance in Covid-19 patients.

immunology↗