Scandinavian Journal of Immunology最新文献

Oligoarticular juvenile idiopathic arthritis (oligoJIA) constitutes nearly 60% of all JIA cases. The immune mechanisms involved in the pathogenesis remain incompletely understood. Few proteomic studies have been performed using synovial fluid (SF) samples. We conducted an exploratory analysis of plasma and SF samples to define inflammatory profiles, assess plasma-SF correlation and examine longitudinal variations. Using proximity extension assay (PEA), we profiled 92 immune-related proteins in plasma and Sf from 14 oligoJIA patients (untreated or NSAID-treated) and plasma from 28 age and sex-matched healthy controls. Differentially expressed proteins were analysed using gene ontology (GO) and KEGG pathways via STRING. Plasma proteomic immune profiles from oligoJIA patients were highly overlapping with immune profiles of healthy donors. Six proteins were differentially expressed between the two groups. Overall, plasma and SF protein expressions correlated (r = 0.78), mainly driven by 13 proteins including CCL25, FGF21 and KITLG. However, the differentially expressed proteins in plasma did not correlate with those in SF. Longitudinal analysis of 20 SF and 10 plasma samples from one patient revealed immunosuppressive effects of methotrexate (MTX) with distinct kinetics in plasma and SF. Paired SF samples from five patients revealed that cell chemotaxis was a key feature in early disease, distinguishing it from the persistent phase. Immunoprofiling of SF from patients with oligoJIA identified more disease-relevant characteristics than analysis of plasma samples. Several proteins, but not all, correlated between plasma and SF. Early-phase enrichment of chemotaxis suggests that targeting chemokines may offer therapeutic potential for early disease remission.

Type 1 diabetes (T1D) and celiac disease (CeD) are two chronic autoimmune disorders commonly diagnosed during childhood. In this exploratory study we performed flow cytometric immunophenotyping of various immune cell populations in peripheral blood from children with T1D, CeD, a T1D and CeD comorbidity, and from age-matched healthy references (controls). With extensive flow cytometry panels covering subpopulations of both CD4⁺ and CD8⁺ T cells, as well as monocytes and NK cells, our main finding is a tendency towards a higher degree of activated/exhausted T cells in children with a sole diagnosis of CeD compared with healthy references. This was seen through a higher fraction of CD4⁺ T cells positive for PD-1, CCR5 and CCR10, as well as a higher fraction of CD8⁺ T cells expressing PD-1 and CD39. In contrast, children with CeD showed a lower percentage of naïve CD8⁺ T cells compared with healthy references. Other important findings are a skewed CD4⁺/CD8⁺ ratio for children with a comorbidity compared with references, increased fractions of T regulatory cells (Tregs, CD4⁺CD25⁺CD127^low) for all three diagnosis groups compared with references, and a higher percentage of CD56^dimCD16⁺ NK cells with a corresponding lower percentage in CD56^dimCD16^- NK cells in CeD compared to the T1D and CeD comorbidity. Ultimately, analysis of the peripheral immunological milieu might lead to the development of more efficient tools for diagnosis and monitoring, and better treatment options, for children with T1D, CeD, and the rare combination of T1D and CeD.

Juvenile idiopathic arthritis (JIA) encompasses distinct inflammatory subtypes such as polyarticular (pJIA), oligoarticular (oJIA), systemic onset (sJIA) and enthesitis-related arthritis (ERA). The molecular mechanisms underlying these subtypes remain unclear. This study aimed to investigate the differential protein expression in synovial fluid (SF) across these subtypes of JIA using high-throughput proteomics to identify potential diagnostic biomarkers. SF samples were collected from 48 children (45 JIA and 3 non-inflammatory controls). Samples underwent protein extraction, iTRAQ labelling and LC-MS/MS analysis. A total of 282 proteins were identified. Differentially expressed proteins were analysed using fold change (FC) relative to control samples within each iTRAQ set. Principal component analysis (PCA), gene ontology (GO) and KEGG pathway enrichment analyses were performed to assess the biological significance of the identified proteins. Proteins showing > 5FC were prioritised for clustering and biomarker identification. Distinct proteomic signatures were observed across the studied JIA subtypes. PCA revealed the heterogeneity of protein expression in different subtypes of JIA. S-100, Septin-7, MMP-16 proteins were commonly upregulated in the studied subtypes of JIA except oJIA. Haptoglobin was upregulated in all except sJIA. The specific proteins expressed in various subtypes include pyruvate dehydrogenase phosphate in pJIA, haptoglobin-related and fibrinogen proteins in ERA, apolipoprotein and Nck-associated protein in sJIA and leucine-rich alpha-2-glycoprotein in oJIA. GO analysis revealed enrichment in immune-related biological processes, including complement activation, humoral immune response and antigen binding. The differential SF proteomic signatures observed in the studied JIA subtypes indicate different pathogenic mechanisms in JIA.

Systemic lupus erythematosus (SLE) is an example of an autoimmune disease manifesting itself in an aberrated immune response directed against nuclear, cytoplasmic and cell-surface antigens. Among patients, symptoms are frequently intensified in females during their active reproductive years, pinpointing the interaction between reproductive and immune systems. Hence, it is urgent to address the question of how SLE can influence female fertility and the impact of hormones on disease manifestation. Mouse models of SLE are suitable tools for studying in detail the interactions of different systems and the impact of lupus development on the process of oogenesis. Lupus-like symptoms were induced through intraperitoneal injection of hydrocarbon oil pristane in healthy Balb/C mice. A short protocol for hormonal stimulation of humans was adapted for mice. Methods used to follow the immune status of the experimental animals were flow cytometry, ELISpot and ELISA, while the variety of autoantibodies, histology and quality of oocytes were characterised using fluorescent microscopy. A single i.p. injection of pristane induced production of autoantibodies and proteinuria, depositions of IgG-containing immune complexes in the kidneys and ovaries, increased the percentage of pro-inflammatory immune cell subtypes, and the number of plasmacytes secreting anti-dsDNA IgG antibodies. The hormonal stimulation of lupus mice altered ANA immunofluorescence imaging patterns, increased the total number and the percentage of well-developed oocytes, increased glomerular atrophy, and decreased mesangial proliferation in the kidneys. The exhibited impairments of oocytes in lupus mice provide evidence for a disturbed local microenvironment as a result of altered disease course.

The initial aim of this study on Balb/C mice was to investigate the putative effects on feeding and appetite of isopentenyl pyrophosphate (IPP) and E-4-hydroxy-3-methyl-but-2-enyl pyrophosphate (HMBPP), also known as phosphoantigens (pAgs). HMBPP was recently shown to increase blood meal appetite in malaria mosquitoes. Both IPP and HMBPP are metabolites produced by the normal gut microbiota and apicomplexan parasites such as Plasmodium. To explore potential effects on appetite, male and female mice were treated by gavage with these metabolites, and body mass and gene expression were monitored in brain, stomach and small intestine at 3 h and 7 weeks. Body mass gain did not clearly differ between pAg-treated and water control mice. However, beginning between 4 and 7 weeks, the salivary glands of IPP-treated males began to swell. With the autoimmune Sjögren disease (SjD) in mind, we subsequently investigated the salivary glands after 1, 4 and 7 weeks of IPP treatment. Fast gene set enrichment analysis (FGSEA) of marginal zone B-cell (MZB) transcripts from salivary glands, together with B-cell infiltration in both sexes at 4 weeks, suggested similarities to SjD pathology. Using ELISA, we measured serum autoantibodies against Ro52, Ro60 and La. Multivariate analysis at 7 weeks showed treatment-associated trends: levels of anti-Ro52 and anti-La tended to increase in IPP-treated males, but not in females. Notably, IL-6 serum levels displayed a sex-dependent pattern, and PCA analyses of transcriptomic data from brain, stomach and small intestine-though with some exceptions-also indicated differential responses to pAgs between males and females.

Current characterisation of cat dander/hair extracts used for allergy diagnosis or allergen-specific immunotherapy is mainly standardised towards the major allergen Fel d 1, while other allergens such as the lipocalin Fel d 7 are insufficiently characterised in such allergen products. This study aimed to produce recombinant Fel d 7 (rFel d 7) and murine IgG monoclonal antibodies (mAbs) specific to it for quantification in allergen extracts and assess the potential of the mAbs in inhibiting patients' IgE in functional assays. rFel d 7 was expressed in E. coli, purified by Ni-affinity and ion exchange chromatography, and physicochemically characterised by circular dichroism, Fourier-transform infrared spectroscopy, dynamic light scattering and mass spectrometry. Twenty hybridoma cell lines producing Fel d 7-specific mAbs were generated and sandwich ELISA was established for the quantitation of Fel d 7. Six different cat allergen extracts from different manufacturers and prepared from different sources were analysed and the concentration ranged from 0.02 μg/mg to 22.59 μg/mg. A mAb pool recognising non-overlapping epitopes inhibited the binding of human IgE-antigen complex formation (63.7% highest inhibition) and IgE-Fel d 7 cross-linking and consequent degranulation of basophilic cells (57.2% highest inhibition). We demonstrate the vast difference of Fel d 7 content in different cat allergen extracts, highlighting the necessity of improved standardisation of cat allergen extracts. The inhibition results showed that the analysed mAbs effectively inhibit rFel d 7 binding to human IgE, an assay we recommend for assessing the potency of allergen extracts as part of extract standardisation.

Systemic Lupus Erythematosus (SLE) is a chronic autoimmune disease characterised by heterogeneous clinical manifestations and varying degrees of organ involvement. The CD40-CD40 Ligand (CD40L) pathway is implicated in autoimmune responses, with elevated levels of soluble CD40L (sCD40L) observed in SLE patients. This study investigates sCD40L as a biomarker for disease activity and its utility in stratifying patients for CD40L-targeted therapies. Plasma levels of sCD40L were quantified in SLE patients (n = 169) and healthy controls (n = 100). Correlations between sCD40L levels and disease activity measures were analysed using Spearman's correlation and logistic regression. K-means clustering grouped patients based on sCD40L concentrations, and principal component analysis (PCA) was performed to assess relationships among disease activity variables. SLE patients exhibited significantly higher sCD40L levels (median 2.2 ng/mL) than healthy controls (median 0.81 ng/mL; p = 0.0079). Elevated sCD40L levels correlated weakly with higher SLE Disease Activity Index (SLEDAI) scores (p = 0.0418), positive Anti-Nuclear Antibody status (p = 0.0133), increased IgG levels (p = 0.0148) and decreased lymphocyte counts (p = 0.0327). Clustering analysis and PCA revealed that patients with higher sCD40L levels tended to have increased disease activity, elevated anti-dsDNA antibody concentrations, and higher C-reactive protein (CRP) levels. Elevated sCD40L levels in SLE patients correlate with disease activity markers, suggesting its potential as a biomarker for monitoring disease progression and severity. Additionally, sCD40L may aid in stratifying patients who could benefit from CD40L-targeted therapies within a treat-to-target framework. Further longitudinal studies with larger cohorts are warranted to validate and explore the role of sCD40L in personalised SLE treatment strategies.

Acute cellular rejection (ACR) remains a common complication post-liver transplantation despite standardised immunosuppressive regimens. Identifying patients at high risk of ACR is challenging, and new tools for prediction are needed. This study aimed to investigate if proportions of circulating T cells as well as different stages of maturation, exhaustion, and activation of T cells pre-transplantation are associated with ACR in liver transplant recipients within the first year post-transplantation. In the prospective ImmuneMO:SOT cohort study, we recruited participants listed for liver transplantation at Copenhagen University Hospital-Rigshospitalet who subsequently underwent liver transplantation. Before transplantation, we collected blood for extensive immune cell profiling using the standardised DURAClone flow cytometry panel and investigated if proportions of CD4⁺ and CD8⁺ T cells, including Th17, Treg, and memory T cell subsets, as well as their activation and exhaustion states were associated with ACR within 1 year post-transplantation. We included 40 liver transplant recipients, of whom 60% were male and had a median age of 50 years. ACR occurred in 37.5% of liver transplant recipients. We found no associations between investigated proportions of T cell subsets, including CD4⁺ (p = 0.25), CD8⁺ (p = 0.43), Th17 (p = 0.61), or Treg cells (p = 0.54) and ACR. This was consistent across activated and exhausted T cells as well as memory T cell subsets. Our findings suggest that proportions of pre-transplant circulating T cells have limited predictive value for post-transplantation ACR. Investigating if other circulating immune cell populations pre-transplantation are associated with ACR after liver transplantation is warranted.

Traditional organ transplantation relies on the Self-Non-self (SNS) model of immunity, focusing on donor-recipient compatibility and aggressive immunosuppression to prevent acute rejection. Although effective early, this strategy does not prevent chronic rejection and cannot account for operational tolerance, failure of perfectly HLA-matched grafts, or the occasional spontaneous acceptance of a fully mismatched organ. The adaptation model of immunity offers a different lens. In the thymus, "central adaptation" programs T cells to recognise self-peptide-MHC (pMHC) so they can later recognise different tissues to facilitate tissue repair and homeostasis. Whether a graft thrives or fails depends on how quickly this self-oriented circuitry can operate. Autografts and isografts arrive with their own extracellular-matrix (ECM) "memory", and recipient T cells immediately recognise their pMHC, triggering tissue-remodelling responses. Allografts must adapt to new ECM-a transition that is associated higher levels of graft injury allowing indirect antigen presentation. Until adaptation is complete, recipient T cells mount cytotoxic rather than reparative responses because of antigen cross-presentation, during which the graft relies on donor-derived tissue-resident memory T cells (T_RM) to maintain integrity. Therapeutically, interventions that preserve or expand graft-borne T_RM, or that pharmacologically enhance adaptation-receptor signalling, could hasten this donor-to-host reprogramming. By replacing blanket immunosuppression with targeted promotion of tissue-remodelling immunity, the adaptation model charts a path toward long-term graft survival without the lifelong risks of today's regimens.