Dendritic cells (DCs) are rare in human blood, often requiring enrichment prior to analysis. Here, we benchmark commonly used pan-DC enrichment methods by comparing recovered DC subset composition to exvivo references. While all approaches capture major DC populations, recovery is partial and exhibits method-dependent, subset-specific biases. These differences alter the apparent DC composition and may influence downstream analyses. Created with BioRender.com.

This study aimed to characterise the expression and functional heterogeneity of CD49f across CD4+ T cell subsets in human peripheral blood, and to investigate alterations in regulatory T cells (Tregs) and CD4+ T cells in patients with systemic lupus erythematosus (SLE), together with their clinical relevance. A total of 43 newly diagnosed, treatment-naïve SLE patients and 21 age- and sex-matched healthy controls were enrolled. Peripheral blood mononuclear cells were analysed by flow cytometry to assess CD49f expression in CD4 + FoxP3+ Tregs and non-Treg CD4+ T cells. Phenotypic and function-related markers were compared between CD49f + and CD49f- subsets. IL-10 production was evaluated as a functional readout in CD49f-defined Treg subsets. Associations between CD49f-related populations and clinical parameters were analysed, and receiver operating characteristic (ROC) curve analysis was performed to explore their potential clinical relevance. CD49f expression was higher in CD4 + FoxP3+ Tregs than in other CD4+ T cells. CD49f + CD4+ T cells exhibited increased CD226 and decreased CD45RA expression, consistent with an activated phenotype. CD49f + Tregs were enriched in the CD45RA-FoxP3int subset and showed higher CD226 but lower GZMB and Helios expression, indicating attenuated suppressive phenotypic features. In healthy controls, CD49f + Tregs displayed significantly higher IL-10 production than CD49f- Tregs, whereas this functional distinction was lost in SLE patients. The proportions of CD49f + subsets were significantly increased in SLE and correlated with multiple clinical indicators. ROC analysis revealed moderate discriminative performance of CD49f-related subsets, with AUC values ranging from 0.640 to 0.786. In conclusion,CD49f identifies distinct phenotypic and functional states within CD4+ T cells and Tregs. CD49f + CD4+ T cells exhibit activation features, while CD49f + Tregs show phenotypic attenuation accompanied by functional heterogeneity that is preserved in health but disrupted in SLE. Increased CD49f expression in SLE reflects immune imbalance and suggests potential value as a cellular immunological marker rather than a standalone diagnostic tool.

Over the past several decades, cure rates for paediatric hematologic malignancies have improved due to advances in cancer therapy. However, numerous obstacles limit the therapeutic efficacy of paediatric solid tumours, including the tumour's immunosuppressive microenvironment and the lack of specific tumour antigens for targeted therapy. Cancer vaccines, a form of immunotherapy, have been under development for more than half a century. Advances in immunology, materials science, sequencing technologies and bioinformatics have revolutionised cancer vaccine development, achieving substantial success in the prevention and treatment of solid tumours. Despite these achievements, the application of cancer vaccines developed for adults is not fully transferable to paediatric solid tumours because of differences in immune status and metabolic capacity. In clinical practice, most solid tumour vaccines designed for adults are applied directly to paediatric patients without modifications tailored to the unique features of the paediatric immune system. Limited attention has been given to designing cancer vaccines with improved efficacy and reduced toxicity for children and infants. This review discusses paediatric solid tumour vaccines from the immune system against tumour to different antigen types of cancer vaccines, illustrating the unique cancer-immunity cycle of young people and some potential strategies for vaccine modification. Additionally, it discusses the application of paediatric solid tumour vaccines through clinical trial data for conditions such as neuroblastoma, brain tumours and sarcomas. Challenges and potential solutions for enhancing vaccine efficacy, minimising side effects and broadening clinical applications are also addressed.

This schematic illustrates the role of endoplasmic reticulum (ER) stress and PERK inhibition in modulating pancreatic cancer cell fate. ER stress activates the PERK pathway, which contributes to tumor cell survival. Pharmacologic inhibition of PERK, as depicted, leads to two downstream effects: decreased cellular proliferation and increased apoptosis. The diagram highlights the therapeutic potential of PERK-targeting strategies in disrupting cancer cell growth and promoting programmed cell death.

The function of innate immune sensors is intricately shaped by their spatial distribution within cells. cGAS (cyclic GMP-AMP synthase), a key cytosolic DNA sensor, illustrates this principle through its unexpected localisation to diverse organelles-including the nucleus, micronuclei, mitochondria, and plasma membrane. In these compartments, cGAS assumes distinct regulatory states and executes specialised functions. For instance, chromatin-bound nuclear cGAS remains inactive under homeostasis but contributes to genome maintenance during genotoxic stress, whereas mitochondrial or micronuclear cGAS links damage signals to inflammation and cell death. This review synthesises recent advances in the spatial regulation of cGAS, focusing on mechanisms such as membrane interactions and post-translational modifications. We further reframe cGAS as a multifunctional regulator in infection, cancer, autoimmunity, and ageing, and introduce a unifying 'location code' framework. This framework proposes that the combined influence of PTMs, protein interactions, and membrane affinities dictates cGAS localisation, functional output, and pathological outcomes, thereby paving the way for spatially informed therapeutic interventions.

Mycobacterium tuberculosis (Mtb) effectively suppresses host immunity to ensure its survival. We have earlier shown that the Acr1 protein of Mtb can inhibit the differentiation of dendritic cells (DCs). Consequently, in the current study, we examined the role of Acr1 in mitigating autoimmunity. Initially, we observed that Acr1 skews the differentiation of DCs into functionally competent myeloid-derived suppressor cells (MDSCAcr1) that chiefly secrete immunosuppressive molecules, expand regulatory T cells (TregAcr1) and attenuate inflammatory responses. Further, MDSCAcr1 suppress Th17 cells. Acr1 expanded MDSCs with a concurrent increase in myelin oligodendrocyte glycoprotein (MOG)-specific Tregs and a decline in Th17 cells in a murine experimental autoimmune encephalomyelitis (EAE) model and prevented the onset of the disease. These results were further validated in the prophylactic model of EAE. Mechanistically, Acr1 activates Tregs and MDSCs via the TLR-4 pathway, implicating innate immune recognition in Mtb-induced suppression. The results indicate a potential role of Acr1 against autoimmune diseases.

A pivotal strategy in immuno-oncology is the initiation and modulation of adaptive immune responses. Ubiquitin carboxyl-terminal hydrolase L1 (UCHL1), known for its role in protein homeostasis and functionality, is implicated in tumorigenesis. However, its part in the antitumor immunity mediated by CD8+ T cells in lung adenocarcinoma (LUAD) is not yet clear. We harnessed bioinformatics to evaluate the clinical relevance of UCHL1 in LUAD, performed IHC to detect the expression of UCHL1 in LUAD tissue, and utilised qPCR to assess UCHL1 levels in LUAD cells, exploring its correlation with the presence of CD8+ T cells. The effects of UCHL1 on CD8+ T cell vigour have been investigated using lactate dehydrogenase and enzyme-linked immunosorbent assay kits, as well as flow cytometry. The contribution of UCHL1 to ferroptosis was examined with ferrous ion and manganese dioxide assay kits, alongside western blot. Furthermore, we utilised bioinformatics software UbiBrowser and Hdock, in conjunction with co-immunoprecipitation (Co-IP), immunofluorescence, and IP methods, to dissect the interaction between UCHL1 and FHL2. Rescue experiments further clarified the mechanism by which UCHL1 modulates FHL2 in tumour immunity. Invivo experiments confirmed the promoting effect of UCHL1 on tumour growth. Elevated UCHL1 levels in LUAD tissues and cells were observed. Dampening UCHL1 triggered ferroptosis in LUAD cells, which in turn ramped up CD8+ T cell activity and enhanced their tumour-killing potential. Mechanistically, UCHL1 was shown to deubiquitinate the downstream factor FHL2, and knocking down FHL2 could counteract the immunosuppressive effects induced by high UCHL1 levels on CD8+ T cells. UCHL1 inhibitor LDN57444 significantly inhibited tumour growth in mice. Therapies aimed at the UCHL1/FHL2 axis could be effectively paired with immunotherapies, opening new avenues in cancer treatment strategies.

Enolase-1 (ENO1) is a moonlighting protein with multiple functions. When expressed on the cell surface, ENO1 binds plasminogen (PLG) and promotes cell migration by facilitating plasmin (PLM)-mediated extracellular matrix degradation. Here, we observed that inflammatory stimulation significantly upregulated ENO1 expression on the neutrophil surface, both invitro and invivo. An anti-ENO1 monoclonal antibody (mAb), 7E5, which blocks the ENO1-PLG interaction, effectively suppressed neutrophil invasion invitro. In mouse models of acute inflammation, including lipopolysaccharide (LPS)-induced lung injury and necrotic cell challenge, 7E5 treatment markedly reduced neutrophil recruitment and neutrophil extracellular trap (NET) formation. Similarly, the PLG inhibitor tranexamic acid (TXA) attenuated neutrophil recruitment, confirming the critical role of the PLG/PLM system in neutrophil migration. These findings highlight ENO1 as a key regulator of inflammation and neutrophil infiltration. Targeting ENO1 with antibodies could be a promising strategy to mitigate tissue damage caused by excessive neutrophilic inflammation.

Follicular helper T (Tfh), B and regulatory T (Treg) cells are involved in the pathogenesis of chronic rejection (CR) after transplantation. Dihydroartemisinin (DHA) is an antimalarial drug with anti-inflammatory activity; however, the effects and mechanisms of DHA on Tfh, B and Treg cells have not been comprehensively elucidated. The aim of this study was to investigate the effect of DHA on Tfh, B and Treg cells and its preventive effect on CR. Invitro assays demonstrated that DHA not only blocks the induction of Tfh cells and alleviates their supportive effect on B cell differentiation but also directly suppresses B cell activation, differentiation and antibody production. Additionally, DHA promotes the induction of Treg cells and enhances their stability in an inflammatory environment. Invivo studies showed that DHA effectively alleviated CR by suppressing neointimal hyperplasia, myocardial injury and interstitial fibrosis and reducing inflammatory cell infiltration and C4d deposition in allografts. Moreover, DHA decreased the levels of Tfh, germinal centre Tfh, B, germinal centre B, IgG-producing and plasma cells in recipients but increased Treg cell levels in recipients and allografts. Mechanistically, we confirmed that DHA inhibits Tfh cells by blocking IL-2-inducible T cell kinase signalling, suppresses B cells by blocking Bruton's tyrosine kinase signalling, and enhances Treg cells by blocking mTOR signalling while promoting STAT5 signalling. In conclusion, our results verified that DHA inhibits Tfh and B cells and enhances Treg cells to attenuate CR in mice, highlighting its potential applicability in the development of robust treatment options.

Variation in microbiome composition is linked to differences in intestinal immune phenotypes and can be leveraged to identify microbiome-driven contributions to phenotypes of interest. Furthermore, such variation has been associated with differing inter-individual susceptibility to the development of inflammatory bowel disease (IBD), a chronic inflammatory disease of the gastrointestinal tract that is driven by dysfunctional immune-microbiome interactions. Here, we identified that differences in microbiome composition in C57BL/6 mice from two commonly used commercial vendors, Charles River (CR) and Jackson (JAX) Laboratories, were associated with variation in the intestinal immune phenotype, with CR mice having greater Th17 levels and faecal IgA. In turn, CR mice demonstrated enhanced susceptibility to the dextran sulfate sodium (DSS)-induced model of colitis compared to JAX mice. Co-housing studies revealed that CR mice could transmit enhanced susceptibility to colitis to JAX mice, implicating differences in microbiome composition as drivers of disease susceptibility. Faecal metabolomics studies using targeted mass spectrometry revealed several metabolites differentially enriched in colitis-susceptible and colitis-resistant mice. Correlation analysis uncovered metabolites that were both negatively and positively associated with colitis severity. Taken together, our study leveraged natural microbiome variation to identify gut microbial metabolites with the potential to predict the severity of IBD. Importantly, we further establish susceptible and non-susceptible murine microbial communities that represent a tractable system in which to further uncover microbiome contributions to IBD in the DSS-colitis model.