The cellular biology of macrophages underpins the multitude of roles that these cells undertake under homeostatic and inflammatory conditions. Macrophages populate all tissues where they contribute to organ physiology while acting as sensors of health and triggering inflammation in response to organ dysfunction, trauma and infection. Sharing key characteristics such as a highly developed endocytic compartment, secretion of growth factors and cytokines, motility and antigen presentation, macrophages undergo specific adaptations in each niche guided by environmental clues that result in diverse phenotypes that support tissue-specific roles such as iron recycling, synaptic pruning, bone reabsorption and processing of lung surfactant.This review will provide an overview of macrophage biology and heterogeneity that underpin their contribution to homeostasis and inflammation to illustrate their importance as therapeutic targets in a wide range of inflammatory diseases.

Collapse of self-tolerance toward peripheral nervous system antigens initiates chronic inflammatory demyelinating polyneuropathy. This breakdown likely recurs, driving disease onset and flare-ups, providing a window to predict progression before symptoms worsen, yet the mechanisms behind self-tolerance maintenance or disruption remain underexplored. Using a transgenic mouse model with Schwann cell-restricted ovalbumin expression and adoptive transfer of ovalbumin-reactive CD8 T cells, we demonstrate that maintenance of immune tolerance to peripheral nervous system antigens is linked to PD1-axis activity. This is characterized by PD1-axis induction, exhaustion, abortive proliferation and deletional tolerance of the transferred cells within the lymph node environment. Complementary in vitro co-culture demonstrated that lymph node stromal cells ectopically present ovalbumin, as evidenced by proliferation of ovalbumin-reactive CD8 T cells, pointing to cooperation of antigen presentation and PD1-axis activity to maintain peripheral nervous system self-tolerance. To assess whether PD1-axis involvement in peripheral nervous system tolerance extends to human autoimmunity, we analysed a cohort of 110 chronic inflammatory demyelinating polyneuropathy patients, identifying significantly elevated soluble PD1, PD-L1 and TIM-3 levels compared with healthy controls. Further, in typical chronic inflammatory demyelinating polyneuropathy, soluble PD1, PD-L1 and LAG-3 revealed consistent low-to-moderate negative correlations (|r| ≈ 0.3-0.5, P < 0.05) with disease severity. Atypical chronic inflammatory demyelinating polyneuropathy patients displayed no significant associations, likely reflecting cohort heterogeneity and limited sensitivity of clinical measures rather than a lack of biological relevance. Exploratory correlation network analyses reveal increased numbers of immune-checkpoints forming inter-correlated networks in chronic inflammatory demyelinating polyneuropathy compared with healthy controls, suggesting engagement of a broader immune- checkpoint regulatory axis. Through this multilayered translational approach-from early immune decision-making in a mouse model to patient data-we offer a fresh perspective on the immunopathogenesis of chronic inflammatory demyelinating polyneuropathy, implicating the PD1-axis as an influential hub within a broader inter-connected immune-checkpoint network.

Rotaviruses A (RVA) are the most common cause of diarrhea-related death in children under the age of five. Because RV vaccines are live attenuated, their use is limited. This work aimed to develop a multi-epitope vaccination against RVA using reverse vaccinology approaches. The viral protein 6 (VP6) was targeted for predicting B-cell and T-cell epitopes, and the best epitopes from its conserved regions were linked by appropriate linkers; additionally, 50S ribosomal protein L7/L12 was inserted as an adjuvant to the vaccine's N-terminus. The designed vaccine revealed satisfactory antigenicity, allergenicity, toxicity, and physicochemical characteristics. The molecular docking and molecular dynamics (MD) simulation showed strong binding interactions between the vaccine and toll-like receptor 4 (TLR4), signifying improved antigen presentation efficacy. The vaccine immunity simulation showed a significant rise in immunoglobulins and cytokines. Furthermore, the vaccine candidate showed a high likelihood of successful expression in Escherichia coli (E. coli). Our findings suggest that the multi-epitope vaccine candidate exhibits significant potential; however, experimental evaluations are necessary to determine its ability to stimulate the immune system.

Epigenetic modulators may sensitize platinum-resistant ovarian cancer (PROC) to immune checkpoint inhibition by reprogramming the tumor microenvironment. We report clinical and translational findings from a phase II non-randomized study of pembrolizumab and oral azacitidine in 34 women with PROC (NCT02900560). Key eligibility criteria included age 18 years or older, performance status of 0-1, measurable disease, platinum-resistant disease and histologically confirmed epithelial ovarian cancer, fallopian tube carcinoma or primary peritoneal carcinoma. Primary endpoints included safety, tolerability, overall response rate (ORR) and disease control rate (DCR). Secondary endpoints included CA-125 response. The effect of combined epigenetic and immunotherapy was evaluated by transcriptomic analyses of 72 serially biopsied tumors. We show that the combination is moderately well tolerated and most common grade 3-4 adverse events are gastrointestinal side effects and anemia. ORR is 2.9% and DCR is 50%; with 3 of the 27 evaluable patients attaining a CA-125 response. Differential gene expression analyses reveal an upregulation of inflammatory and cytolytic genes and co-inhibitory checkpoints 6 weeks on-therapy. Upregulation of interferon signaling, antigen presentation and immune cell adhesion and migration gene sets are prominent on-therapy, together with an increase in density of CD8 + T-cells. Patients with a CA-125 and/or clinical response show an enrichment of adaptive and conserved immune response gene sets on-therapy. Our findings highlight the potential of epigenetic modulators to re-shape the tumor microenvironment of PROC toward a more inflammed phenotype and may point to approaches to augment immunotherapy response.

Tumor-derived extracellular vesicles (TEVs) are promising autologous cancer vaccines due to their intrinsic tumor-associated antigens. However, their translation is hindered by immune evasion and the lack of non-invasive tools to monitor vaccination efficacy in vivo. Here, we report a self-reporting nanovaccine engineered by coating TEVs under microfluidics with pH-sensitive manganese dioxide (mTEV). This surface biomineralization on TEVs chemically block inhibitory ligands such as CD47, promoting dendritic cell (DC) uptake and degrades under lysosomal conditions to expose tumor antigens and release Mn2+. The released Mn2+ activates the cGAS-STING pathway and simultaneously enhances T1-weighted magnetic resonance imaging (MRI) contrast, enabling visualization of DC trafficking. In ovarian cancer models, mTEVs drove robust DC maturation, antigen presentation, and cytotoxic T cell responses, effectively suppressing tumor growth and peritoneal dissemination. Importantly, early MRI signals in draining lymph nodes correlated with treatment outcomes, providing a non-invasive predictive biomarker of vaccine efficacy. This dual-functional nanovaccine platform integrates immune activation with in vivo tracking, offering a precision strategy for cancer immunotherapy.

Ankylosing spondylitis (AS) and enthesitis-related arthritis (ERA) are autoimmune bone diseases characterized by prominent heterotopic ossification and are both poor prognosis. The pathological mechanisms of these diseases remain poorly understood. After single-cell RNA-seq and TCR profiling, we used flow cytometry and multiplex immunofluorescence to quantify and map specific immune cell subsets within lesions of early rheumatoid arthritis and ankylosing spondylitis (AS), analyzing a total of 33 patient specimens. Furthermore, we identified a peptide from versican, a chondroitin sulfate proteoglycan of ligament, to establish AS mouse model. In the novel model, immune-cell quantification, spatial mapping, and targeted therapies were applied to elucidate the pathogenic roles of key cellular subpopulations. Conventional type 1 dendritic cells (cDC1s) were enriched in the joints of patients with ERA and exhibited a high level of MHC I antigen presentation, which robustly interact with CD8+ T cells. Moreover, cDC1s, harboring the molecular of MHC I antigen presentation, were detected in spinal ligament tissue of patients with AS. In mice, versican-derived peptide combined with type II collagen stably and efficiently elicits a model exhibiting hallmark enthesitis and heterotopic ossification. In this model， cDC1s and IL-17A+CD8+ T cells were highly enriched in the ligamentous synovial tissues. Blocking the recruitment of cDC1s through XCL1 neutralizing antibody alleviates arthritis symptoms in vivo. Thus, cDC1s promote autoimmune reactions and osteoarticular lesions through IL-17A+CD8+ T cells. Targeting cDC1 represents a novel therapeutic target for bone remodeling arthritis.

Impaired dendritic cell (DC) recruitment, maturation, and antigen presentation within the immunosuppressive tumor microenvironment (TME) critically limit the efficacy of cancer immunotherapies. Strategies attempt to restore DC function using systemically administered granulocyte-macrophage colony-stimulating factor (GM-CSF) are constrained by poor tumor accumulation and dose-limiting toxicity. Herein, we developed a biosynthetic, ultrasound-triggered in situ cancer vaccine based on a hybrid nanoplatform (OMVsGM-Lip@Ce6) that integrates GM-CSF-expressing bacterial outer membrane vesicles (OMVsGM) with pH/ultrasound-responsive liposomes encapsulating the sonosensitizer chlorin e6 (Ce6). In the acidic TME, the hybrid vesicles destabilize, enabling localized release of biosynthetically loaded GM-CSF. Subsequent local ultrasound irradiation activates Ce6 to generate reactive oxygen species (ROS), inducing immunogenic cell death (ICD) and thereby promoting the in situ release of tumor-associated antigens (TAAs) and damage-associated molecular patterns (DAMPs). These endogenous danger signals, together with pathogen-associated molecular patterns (PAMPs) intrinsically carried by OMVs, synergize with locally delivered GM-CSF to enhance DC recruitment, expansion, and maturation, ultimately facilitating efficient antigen presentation and priming of tumor-specific T-cell responses. This biosynthetic OMVs-based platform thus realizes spatially controlled GM-CSF delivery and self-adjuvanted in situ cancer vaccination, effectively remodeling the immunosuppressive TME and eliciting robust systemic antitumor immunity to overcome resistance to immunotherapy.

We compared duodenal biopsies showing active celiac disease (CeD) to normal controls using single-cell RNA sequencing, cyclic immunofluorescence, RNAScope, and proximity ligation assays. There is increased infiltration of villous but not crypt epithelium T cells bearing either αβ or γδ T cell receptors (TCRs) in CeD. Both T cell subsets are activated cytotoxic T lymphocytes (CTLs) and are the predominant mucosal source of IFNγ. In response to this IFNγ, villous but not crypt enterocytes show an IFNγ signature, including nuclear phospho-STAT1 protein, class II HLA molecules and IFNγ-inducible chemokines known to recruit CTLs (e.g., CCL3, CCL4, CXCL10, and CXCL11) and receptors for these chemokines are expressed on the infiltrating CTLs. Villous enterocytes also display increased HLA-E and HLA-B mRNAs and proteins. Bioinformatic analyses (NICHES) and proximity ligation assays show frequent binding of both αβ and γδ TCRs with enterocyte HLA-E or HLA-B, but not HLA-DR. In contrast, NKG2C, proposed as an alternative trigger of CTL activation, is infrequently expressed and shows few interactions with HLA-E. Our data suggest that activated intraepithelial CTLs produce IFNγ which recruits additional CTLs and increases antigen-dependent killing of villous epithelium using either conventional or HLA-E antigen presentation.

Estrogen receptor (ER) positive breast cancer is the most prevalent subtype, commonly responsive to endocrine therapies. Immune checkpoint inhibitors (ICIs) have limited efficacy in ER-positive disease, highlighting the need for the development of combination immunotherapies for these patients. We previously established that nitroso-N-methylurea-induced mammary tumors in outbred Sprague-Dawley rats mimic immune evasive mechanisms and the heterogeneity of ICI response observed in patients. We identified a "luminal growing" gene signature in ER-positive tumors, which correlated with tumor growth and immune-related differences. Here, we evaluated targeting candidates from this signature KMT5B/C and IKBKE using inhibitors A-196 and IKBKEi respectively, alongside anti-estrogen (fulvestrant) and a TGFβ blocking antibody (NIS793), both individually and in combination with αPD-L1, within this rat model. Fulvestrant emerged as the most effective treatment, inducing regression of most existing tumors and reducing on-treatment tumor burden when combined with αPD-L1. A-196, while ineffective as a monotherapy, demonstrated enhanced response when combined with αPD-L1. Comprehensive tumor profiling through polychromatic flow cytometry and single-cell RNA sequencing revealed that A-196 induced a luminal-to-basal shift in tumor epithelial cells, enhancing antigen presentation, whereas epithelial-to-mesenchymal transition was linked to fulvestrant resistance. Our findings underscore the value of the rat mammary tumor model for preclinical studies in ER-positive breast cancer and advocate for the further validation and potential clinical development of KMT5B/C inhibitors to enhance the efficacy and broaden the applicability of ICI therapy in cancer patients.

Osteosarcoma, the most prevalent primary malignant bone tumor in children and adolescents, remains a formidable clinical challenge due to its high metastatic potential and limited therapeutic progress over the past three decades. While surgery combined with multi-agent chemotherapy has improved outcomes for patients with localized disease, prognosis for those with recurrent or metastatic osteosarcoma remains poor. Although immunotherapy has revolutionized cancer care across multiple malignancies, its efficacy in osteosarcoma has been modest, largely owing to an immunosuppressive tumor microenvironment, functional T cell exhaustion, and pronounced antigenic heterogeneity. Recent advances in T cell–based strategies, including MHC-independent γδ T cells, immune checkpoint inhibitors targeting PD−1/PD−L1 and CTLA−4, and chimeric antigen receptor (CAR) T cells directed against antigens such as HER2, GD2, and B7−H3, have demonstrated encouraging preclinical activity but limited clinical translation. Emerging evidence suggests that impaired antigen presentation, suppressive immune cell populations, and inadequate T cell trafficking collectively restrict therapeutic efficacy. This review summarizes recent mechanistic and translational advances in T cell–directed immunotherapy for osteosarcoma and proposes future directions to improve clinical outcomes.

Oncolytic viruses (OVs) represent a promising strategy in cancer immunotherapy, as they selectively infect and lyse tumor cells while simultaneously triggering robust antitumor immune responses. By inducing immunogenic cell death, OVs enhance tumor antigen presentation and initiate a systemic immune response, effectively transforming the tumor microenvironment from an immune-suppressive state to an immune-permissive state. In addition to exerting direct oncolytic effects, OVs modulate key tumor-associated biological processes, including tumor angiogenesis and extracellular matrix remodeling, disrupting tumor progression and metastasis. Notably, recent advances have highlighted the therapeutic potential of combining OVs with conventional and emerging cancer treatments, such as chemotherapy, radiotherapy, immune checkpoint inhibitors, adoptive cell therapy, and epigenetic-targeted drugs. These combination strategies demonstrate synergistic effects by improving tumor selectivity, increasing antitumor immunity, and overcoming treatment resistance. Nevertheless, persistent challenges, such as viral dissemination dynamics, therapy resistance, and regulatory complexities, impede the broad clinical implementation of oncolytic virus therapy (OVT). In this Review, we illustrate recent advancements and innovative therapeutic strategies in OVT within the context of contemporary cancer treatment paradigms. First, we outline the historical evolution and key milestones in OVT development. We then discuss the classification of OVs and their multimodal mechanisms that target tumorigenesis, metastasis, disease recurrence, and therapy resistance. Finally, we evaluate the clinical research progress of OVT applications, focusing on their integration with other therapies, analyze the translational barriers hindering clinical implementation, and propose evidence-based future directions for optimizing cancer treatment.

Hyperbranched polycation-based hierarchical assembles as vaccine carrier for cascaded antigen delivery and enhanced immunity response.

Optimizing bridging radiotherapy prior to CAR-T cell therapy: An evidence-based approach.

The development of allele-specific KRAS inhibitors underscores the importance of understanding the distinct tumor biology associated with common KRAS mutations, G12D and G12C, in genetically engineered mouse models (GEMMs) of non-small cell lung cancer (NSCLC) and patient samples. Lung tumors driven by the most common KRAS mutation, G12C, show delayed onset and slower progression compared with those driven by KRAS G12D in patients and mice. G12C tumors display lower proliferation and increased immune cell engagement, the latter of which is consistent with observations in patient tumors. Allele-specific KRAS G12C/D inhibitors effectively suppress the growth of respective autochthonous lung tumors. However, G12D-driven tumors relapse more rapidly than G12C-driven tumors in autochthonous models, reflecting greater intrinsic aggressiveness. Given this aggressive clinical behavior, we focused on elucidating the mechanism of action and strategies to potentiate KRASG12D inhibition in nonimmunogenic and immunogenic lung cancer models. G12D inhibition enhances tumor antigen presentation, activates T cells, and enables antigen-specific cytotoxicity, leading to efficacy with immune checkpoint blockade combination. This combination induces durable immune memory in immunogenic models but not in nonimmunogenic settings. Our findings underscore key differences between KRAS G12D and G12C mutations in shaping lung cancer biology, reveal distinct resistance dynamics under long-term targeted therapy, and uncover immune-mediated mechanisms specific to KRASG12D inhibition with direct clinical and translational relevance.

Recent research has challenged a long-held view of the brain as an immune-privileged organ, revealing active immunosurveillance with therapeutic relevance. Using a new genetically engineered mouse model of ZFTA-RELA ependymoma, a childhood brain tumor, we characterized an immune circuit between the tumor and antigen-presenting hematopoietic stem and progenitor cells (HSPCs) in the skull bone marrow. The presentation of antigens by HSPCs to CD4+ T cells biased HSPC lineages toward myelopoiesis and polarized CD4+ T cells to regulatory T cells, culminating in tumor immunotolerance. Remarkably, normalizing hematopoiesis with a single infusion of antibodies directed against cytokines enriched in the cerebrospinal fluid of mice bearing ZFTA-RELA ependymomas, choroid plexus carcinomas or group 3 medulloblastoma-all aggressive childhood brain tumors-disrupted this process and caused profound tumor regression. These findings demonstrate the existence of a skull bone marrow-tumor immunological interface and suggest that modulating the local supply of myeloid cells could represent a less toxic therapeutic strategy for aggressive childhood brain tumors.

Holosteans (gars and bowfins) have emerged as valuable models for understanding early vertebrate evolution, offering insights into diverse topics ranging from genomic architecture to molecular processes. These lineages also exhibit unusual features in their immune response, combining molecular elements seen in both tetrapods and ray-finned fishes. However, the immune repertoire of holosteans remains relatively unexplored. Here, we investigate the evolution of PSMB8, a core component of the immunoproteasome responsible for cleaving intracellular proteins into peptides for presentation by MHC class I molecules. We identify two holostean PSMB8 types-S type and K type-that are unique among vertebrates. These types likely cause significant biochemical changes to the S1 binding pocket involved in antigen cleavage which could result in the presentation of novel peptides by MHC class I. Integrating comparative analyses across major ray-finned fish lineages demonstrates that bowfins and gars independently evolved the PSMB8 S type within separate PSMB8 paralog lineages, while the PSMB8-K type is an evolutionary novelty found only in gars. Our results provide new perspectives into PSMB8 haplotypes and their role in peptide antigen processing, offering unique insights into the molecular evolution of the vertebrate immunity and antigen presentation.

Mycobacterium tuberculosis (Mtb) employs multiple strategies to evade host immunity, including disruption of antigen presentation. Dendritic cells (DCs) are crucial for effective antigen presentation and T-cell activation. In this study, we show that the mycobacterial protein ESAT-6 impairs monocyte to DC differentiation, with reduced expression of the DC markers CD209 and CD1a. ESAT-6 treatment elevated IL-6 and IL-10 levels, but blocking the biological activity of these cytokines failed to restore DC differentiation. Mechanistically, ESAT-6 suppressed phosphorylation of p65, establishing that ESAT-6 impairs DC differentiation by inhibiting NF-κB activation, a function dependent on the last six amino acids of its C-terminal domain. This mechanism may represent a novel immune evasion strategy employed by Mtb to subvert host adaptive immune responses during infection.

Loss of TREM2 impairs microglial function and exacerbates retinal neurodegeneration in glaucoma.

Hepatocellular carcinoma (HCC) remains a major global health burden, partly due to the lack of physiologically relevant in vitro models that accurately recapitulate early host-virus interactions and immune responses. Human Hepatocyte Line 5 (HHL-5) is an immortalized hepatocyte cell line that retains key liver-specific functions. This study aimed to characterize the phenotypic, genetic, and metabolic features of HHL-5 cells and evaluate their suitability as a non-cancerous hepatic model, in comparison with the HCC cell line HepG2. Morphological and phenotypic assessment of cells showed smaller cell and nuclear areas and slower proliferation with markedly longer doubling time of HHL-5 cells than HepG2 cells. Genomic analyses using whole-exome sequencing revealed enrichment of immune-related pathways in HHL-5 cells, including antigen processing and presentation, whereas HepG2 cells showed predominance of DNA replication pathways. Metabolomic profiling of cells by nuclear magnetic resonance spectroscopy showed hepatocyte-like oxidative profiles of HHL-5 cells, in contrast to the glycolytic phenotypes of HepG2 cells. Moreover, Western blotting for selected proteins showed reduced expression of oncogenic and stress-response markers, including c-Myc, pSTAT3, pNrf2, and select cytochrome P450 enzymes. Our findings support HHL-5 cells as a robust non-cancerous in vitro model for investigating liver diseases, viral infection, and early events in hepatocarcinogenesis. Not applicable.

Current understanding of B cell heterogeneity in diffuse large B cell lymphoma (DLBCL) and its functional impact on disease progression remains incomplete. This study applies single-cell RNA sequencing to identify and characterize a distinct proliferation-related B cell subpopulation in DLBCL, aiming to address this knowledge gap. We utilized dataset GSE182434 from the Gene Expression Omnibus (GEO) database for the analysis, with the aim of identifying genes that are specifically highly expressed in different cell clusters. The copy number variation analysis was performed using B cells of normal samples as the control. Thereafter, the cell-cell communication analysis was implemented to reveal the potential ligand-receptor pairs, and the functional enrichment analysis was performed to uncover the enriched pathways. Further, the potential transcription factors-target genes networks were plotted via SCENIC analysis, and a series of validation assays were implemented using DLBCL cells. The single-cell landscape of DLBCL revealed a reduced proportion of B cells, CD8+ T cells, and naïve T cells. Malignant B cells exhibited chr1q amplification and chr6 deletion, with genes in these regions linked to immune suppression and impaired antigen presentation, respectively. Further subclustering identified a proliferative B cell subcluster (subcluster 2) enriched in nucleotide metabolism and cell cycle pathways. This subcluster was characterized by elevated XBP1 activity, regulating ER stress response, and downregulation of SPIB, RELB, and IRF factors involved in lymphocyte activation and interferon signaling. Functionally, XBP1 silencing suppressed DLBCL cells proliferation and invasion. Cell communication analysis revealed crosstalk between this B cell subpopulation and CD8+ T/NK cells via MIF-(CD74+CXCR4) and LTA-TNFRSF pathways. This analysis has identified and characterized the proliferation-related B cells in DLBCL, which may provide some ideas for the treatment strategies in immune-oncology and cellular therapies.