small molecules

2026-09-23 | GHSR and TLR4 collectively promote hepatic inflammation and aberrant repair in alveolar echinococcosis.

Alveolar echinococcosis (AE) is a fatal zoonotic parasitic disease that causes progressive hepatic injury through chronic inflammation, aberrant proliferative repair, and liver fibrosis. GHSR and TLR4 individually regulate hepatic inflammation and proliferation; however, their synergistic roles in Echinococcus multilocularis (E. multilocularis)-induced AE remain unclear. Wild-type (WT), GHSR-knockout (GHSR-/-), and TLR4-knockout (TLR4-/-) murine AE models were established, and comprehensive evaluations of hepatic pathology, cell proliferation, macrophage polarization, inflammatory factors, and hepatic proteomic profiles were performed at 12 weeks post-infection. Knockout of either GHSR or TLR4 alleviated AE-induced hepatic lesions, fibrosis, and liver dysfunction. Mechanistically, their deletion suppressed PI3K/Akt-mediated proliferation and TLR4/MyD88/NF-κB-mediated inflammation, reduced M1/M2 macrophage infiltration, decreased pro-inflammatory cytokines (IL-6, TNF-α, and TGF-β1), and elevated anti-inflammatory IL-10. A positive expression correlation between GHSR and TLR4 was confirmed in AE, Proteomics further verified their coordinated modulation of hepatic inflammation and aberrant repair. Collectively, upregulated GHSR and TLR4 jointly promote Echinococcus multilocularis-associated hepatic damage via sustaining persistent inflammation and dysregulated proliferative tissue repair. This study demonstrates coordinated pro-pathological involvement of GHSR and TLR4 in AE progression and provides in vivo and proteomic evidence supporting the exploration of targeted interventions against parasitic liver disorders.

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2026-09-23 | Albendazole Treatment of Alveolar Echinococcosis in a Trial Based on a Cross Sectional Ultrasound Study in Kyrgyzstan.

Human alveolar echinococcosis (AE) is a potentially fatal parasitic disease. In the low-resource country of Kyrgyzstan, it is essential to develop protocols to manage the large number of AE cases being diagnosed. A randomised trial was undertaken to explore the hypothesis that subjects with small AE lesions, detected by ultrasound, a wait and see approach could be adopted. Alternatively, subjects could be managed by albendazole and avoid invasive surgical treatment. One group of subjects with small P1N0M0 lesions was treated with albendazole. A second group remained untreated. A third group, with larger lesions, was either treated with albendazole or referred for surgical intervention. Patients were monitored for up to 2.5 years by ultrasound every 3-4 months. Subjects in the wait and watch group were switched to albendazole treatment if their lesions progressed. The study was registered at clinicaltrials.com. Registration number NCT07182305. Of the 97 subjects initially assigned to the wait and watch group, 22 had signs of lesion progression and were placed on albendazole therapy. Subjects on continuous albendazole therapy demonstrated a reduction in the mean lesion size during the course of the study. In hyperendemic areas of AE, wait and see for small lesions or combined with albendazole therapy is a realistic approach to the management of AE cases. Frequent follow up with imaging every 3-4 months is essential to monitor any disease progression.

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2026-09-08 | The application of imaging mass cytometry in the immune microenvironment of alveolar echinococcosis.

Hepatic alveolar echinococcosis (HAE) is a chronic parasitic disease caused by infection with the larval form of Echinococcus multilocularis, characterised by the formation of invasive lesions in the liver, which involve the proliferation of immune system cells in response to the pathogen. Although surgical resection is the treatment of choice, patients in advanced stages often lose the opportunity for surgery, and drug therapy has limited efficacy. The immune microenvironment plays a key role in tumour progression, but its spatial heterogeneity in HAE has not yet been systematically elucidated. Tissue samples for this study were obtained from the tissue proximal to the lesion and matched distal liver tissue from three patients with HAE. Imaging mass cytometry (IMC) analysis was performed using an antibody panel comprising 28 immunological markers. PhenoGraph clustering and t-SNE dimensionality reduction techniques were applied to classify and visualise single-cell data, and to analyse spatial interactions between cells. Both the tissue proximal to the lesion and the distal liver tissue exhibited significant immune cell infiltration and marked spatial heterogeneity. The tissue proximal to the lesion was characterised primarily by activated CD8+ T cells (Cluster 3/19) and CD56+ NK cells (Cluster 17/18), presenting an immune-activated state and forming tertiary lymphoid structure (TLS)-like structures. B cells (Cluster 1) were reduced in number in the proximal lesion, whilst macrophages (Cluster 6) showed significant colocalisation with B cells, suggesting that macrophages may regulate B cell function through processes such as antigen presentation. This study utilised IMC technology to reveal the complex landscape and heterogeneity of the HAE immune microenvironment, providing new targets and insights for the development of immunotherapeutic strategies for this disease.

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2026-09-06 | Poly(hydroxybutyrate) nanoparticle-encapsulated albendazole enhances in vivo efficacy against the Echinococcus multilocularis germinal layer.

Alveolar echinococcosis (AE), caused by the larval stage of Echinococcus multilocularis, is a severe zoonosis requiring prolonged anthelmintic therapy. Albendazole (ABZ) remains the treatment of choice; however, its poor aqueous solubility and low systemic bioavailability limit therapeutic efficacy and necessitate prolonged high-dose regimens. Improving the delivery of existing antiparasitic drugs therefore represents a valuable therapeutic strategy. This study evaluated the in vivo chemoprophylactic and therapeutic efficacy of an innovative nanomedicine formulation comprising ABZ encapsulated in poly(hydroxybutyrate) (PHB) nanoparticles synthesized by electrospraying. The resulting formulation demonstrated high reproducibility, adequate drug loading, and stable physicochemical characteristics suitable for in vivo evaluation. Efficacy was assessed in an experimental murine model of intraperitoneal alveolar echinococcosis using chemoprophylactic and therapeutic protocols. In the chemoprophylactic study, ABZ-loaded PHB nanoparticles significantly reduced cyst weight compared with the untreated control group and induced extensive ultrastructural damage to the germinal layer, outperforming the ABZ suspension. In the therapeutic protocol, the polymeric nanocarrier system significantly impaired metacestode tissue viability relative to the untreated control. Notably, despite the lack of a statistically significant difference in the cyst weights compared to the ABZ suspension, the nanoparticle treatment induced far more pronounced ultrastructural alterations in the germinal layer. This severe damage, characterized by a marked reduction in germinative cells, effectively compromised the regenerative capacity and proliferative potential of the metacestode tissue. In conclusion, the electrosprayed PHB nanocarrier system represents a promising biopharmaceutical strategy to optimize ABZ delivery, enhancing its therapeutic performance against experimental alveolar echinococcosis without requiring increased drug dosages.

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2026-08-31 | Repurposing niclosamide ethanolamine for alveolar echinococcosis reveals a disconnect between in vitro efficacy and in vivo outcome in the intraperitoneal infection model.

Echinococcosis is a zoonotic disease caused by cestodes of the genus Echinococcus. Alveolar echinococcosis (AE), caused by E. multilocularis, primarily affects the liver and shows infiltrative, tumor-like growth of the metacestode stage. If untreated, AE is lethal. AE remains a neglected disease with current treatments based on albendazole or mebendazole that are parasitostatic, and not curative, underscoring the need for more effective therapies. Niclosamide is a chlorinated salicylanilide derivative with proven activities against intestinal helminths but is inactive against tissue-dwelling helminths due to poor absorption and limited bioavailability. In this study, we repurposed niclosamide ethanolamine (NEN), a formulation with improved systemic exposure, for the treatment of E. multilocularis infection in vitro and in vivo. We assessed the in vitro efficacy of niclosamide and NEN against E. multilocularis metacestode vesicles (IC50 < 0.2 µM) and primary parasite cells (IC50 < 0.3 µM), with active concentrations largely corresponding to NEN levels reachable in the liver. Metabolic analysis suggested that NEN acts as a mitochondrial uncoupler. Electron microscopy showed that NEN-treatments induced profound structural damage in the metacestode vesicle tissue, but mitochondrial ultrastructure was not notably affected. In mice intraperitoneally infected with E. multilocularis, NEN was orally administered during 9 weeks either alone, or in combination with albendazole. Pharmacokinetic analyses showed that NEN reached blood level concentrations above 1 µM. However, the parasite burden in NEN-treated mice was not significantly reduced under the conditions used in this study. Although niclosamide and NEN demonstrated potent activity against E. multilocularis in vitro, this efficacy did not translate in the mouse model. The lack of in vivo activity could be attributed to several factors such as infection model, limited drug uptake by the parasite in the animal, or the rapid metabolization of the compound. Future studies should explore novel niclosamide derivatives and formulations to enhance efficacy against AE in vivo.

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cell therapies

2026-09-04 | The CNTN1/Gilz pathway mediates the therapeutic effect of mesenchymal stem cells on Echinococcus multilocularis-induced hepatic inflammation and fibrosis.

Mesenchymal stem cells (MSCs) exhibit potent immunomodulatory properties, yet their precise mechanisms in alleviating Echinococcus multilocularis-induced hepatic inflammation and fibrosis in Alveolar Echinococcosis (AE) remain elusive. This study aimed to elucidate the immunoregulatory mechanisms underlying MSCs therapy in AE. Using an AE mouse model, we demonstrated that MSCs administration significantly ameliorated liver histopathology, attenuated fibrosis, and restored liver function. Molecular analyses revealed that AE infection promoted a pro-inflammatory profile (elevated RORγt and IFN-γ) while suppressing regulatory factors (FOXP3, TGF-β1, IL-10, CNTN1, and Gilz), effects that were robustly reversed by MSCs treatment. In vitro, co-culture of CNTN1-knockdown MSCs with E. multilocularis antigen-stimulated CD4+ T cells demonstrated that CNTN1 deficiency impaired MSCs-mediated immunoregulation, decreased IL-10 secretion, and disrupted the Th17/Treg balance. Mechanistically, dual-luciferase reporter assays confirmed that CNTN1 directly activates the Gilz promoter. Collectively, our findings identify the CNTN1/Gilz signaling axis as an essential mediator of MSCs immunomodulation, providing novel mechanistic insights into the therapeutic efficacy of MSCs against E. multilocularis-induced hepatic injury.

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2026-03-09 | Alveolar echinococcosis drives functional reprogramming of hepatic CD8+ T cells.

Alveolar echinococcosis (AE), caused by the larval stage of Echinococcus multilocularis, exhibits infiltrative, tumor-like behavior in the liver and persists within its tolerogenic immune environment. Although T cells are central to host defense, the stage-specific remodeling of their lineage states during AE remains unclear. A secondary AE infection model was established by portal vein injection of approximately 1,000 viable protoscoleces in C57BL/6 mice. Liver tissues collected at 3 days (3 dpi) and 3 months (3 mpi) post-infection were analyzed using single-cell RNA sequencing (scRNA-seq), flow cytometry, and multiplex immunofluorescence to characterize T-cell subset composition, transcriptional programs, and potential interactions with dendritic cells (DCs). scRNA-seq of 78,290 high-quality cells identified 13 immune and non-immune populations and revealed strong temporal shifts in hepatic immunity. Early infection featured macrophage-driven inflammation with reduced T-cell proportions, whereas late infection showed marked expansion of both T cells and DCs. CD8+ T-cell profiling demonstrated the establishment of a diversified compartment composed of cytotoxic, effector-memory, and exhausted subsets. These subsets exhibited coordinated transcriptional remodeling, including upregulation of regulatory genes (Btg1, Tnfaip3, Junb, Nr4a1) and downregulation of early-induced inflammatory and metabolic genes, indicating adaptation to sustained antigen exposure. Spatial imaging further revealed ring-like accumulation of CD11c+ DCs around lesions with adjacent clustering of CD8+ T cells, and ligand-receptor analysis highlighted Thy1-Adgre5 as a prominent DC-T-cell interaction axis. AE infection drives a transition from acute inflammation to chronic immune regulation through extensive lineage diversification and functional reprogramming of CD8+ T cells. Spatially organized DC-T-cell interactions likely contribute to maintaining a regulated yet immunologically active microenvironment, providing insights for targeting chronic-stage immune responses in AE.

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2026-02-06 | The gut microbiota mediates depression-like behaviors in mice with chronic Echinococcus multilocularis infection.

Alveolar echinococcosis (AE), a chronic parasitic disease caused by Echinococcus multilocularis (E. multilocularis), remains poorly characterized with respect to central nervous system (CNS) involvement, and its long-term effects on mental health have not been systematically investigated. In this study, we established a BALB/c mouse model of chronic E. multilocularis infection and applied an integrative framework combining behavioral assessments, histomorphological analyses (hematoxylin-eosin staining, Nissl staining, and transmission electron microscopy), cytometric bead array (CBA), and multi-omics approaches (16S rRNA sequencing, metagenomics, and untargeted metabolomics) to investigate infection-induced neuroimmune-gut microbiota interactions. Chronically infected mice exhibited pronounced depression-like behavioral phenotypes, accompanied by hippocampal neuronal nuclear membrane atrophy and disrupted microglial homeostasis. Both peripheral and central inflammatory profiling revealed elevated levels of pro-inflammatory mediators, particularly IL-6 and MCP-1, suggesting coordinated systemic immune activation and neuroimmune alterations. Notably, fecal microbiota transplantation (FMT) from infected donors was sufficient to induce depression-like behaviors in recipient mice, supporting a contributory role of infection-associated gut microbiota alterations in behavioral abnormalities. Integrated multi-omics analyses further revealed a marked reduction in Lactobacillus abundance in infected mice, which was positively correlated with decreased levels of key metabolites within the tryptophan/5-hydroxytryptamine (5-HT) metabolic pathway. Collectively, these findings suggest that chronic E. multilocularis infection may be associated with depression-like behaviors through gut microbiota dysbiosis and related metabolic perturbations. This study provides initial insights into the potential mechanisms underlying neuropsychiatric complications in AE and proposes a conceptual framework for future investigations into early intervention and microbiota-targeted therapeutic strategies.

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2025-09-20 | Alveolar Echinococcosis Mimicking Perihilar Cholangiocarcinoma Leading to Liver Transplant: A Case Report.

BACKGROUND Alveolar echinococcosis (AE) is a slowly progressive parasitic disease that primarily affects the liver and resembles primary or secondary liver neoplasms. Differentiating AE from other primary or secondary liver malignancies is of paramount importance, due to differing therapeutic approaches. The disease is uncommon in developed countries. Initial extrahepatic manifestation mimicking a primary biliary neoplasm is extremely rare. A broad differential diagnosis and low disease prevalence make the diagnosis of primary biliary AE extremely challenging. CASE REPORT We present a 32-year-old male patient with perihilar AE and no significant past medical history. The initial clinical presentation and radiological findings were compatible with the diagnosis of perihilar cholangiocarcinoma (Klatskin tumor). The patient subsequently underwent extensive invasive diagnostic procedures, including endoscopic ultrasound and endoscopic retrograde cholangiopancreatography, which led to choledochal perforation and biliary leakage, necessitating urgent surgical procedure, along with exploration, evacuation of enlarged lymph nodes, and subsequent histopathological examination. None of the procedures provided definitive evidence of malignancy. Only an ultrasound-guided percutaneous biopsy followed by histopathological examination revealed AE. Albendazole treatment and close follow-up were initiated. Subsequently, the patient experienced recurrent episodes of acute cholangitis. Recurrent cholangitis and perihilar biliary involvement, precluding radical surgical resection, necessitated liver transplantation. Ultimately, the patient underwent orthotopic liver transplantation from a brain-dead donor, with a favorable outcome. CONCLUSIONS Liver transplantation is a definitive treatment option for selected patients with perihilar liver involvement precluding radical resection of parasitic mass and recurrent episodes of acute cholangitis.

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2025-09-03 | Efferocytosis-Driven M2 Macrophage Impairs Fibrotic Encapsulation and Promotes Echinococcus multilocularis Growth in Cotton Rats (Sigmodon hispidus).

Alveolar echinococcosis, caused by Echinococcus multilocularis, exhibits significant species-dependent susceptibility. This study compared the early hepatic tissue responses to E. multilocularis in highly susceptible cotton rats (Sigmodon hispidus) and laboratory mice (DBA/2 and AKR/N). Following oral administration of E. multilocularis eggs, cotton rats developed a greater number of hepatic lesions within 2 weeks, whereas mice required 4 weeks to develop smaller lesions. Histopathology revealed accelerated multilocular cyst formation in cotton rats. Unlike mice, which formed dense collagenous layers isolating cysts, cotton rats lacked adventitial layers despite similar fibrotic thickness. Immunohistochemistry revealed abundant CD206+ macrophages at cyst peripheries in cotton rats, engaging in efferocytosis of apoptotic neutrophils with expression of TGF-β, galectin-3, and VEGF. Efferocytic macrophages expressed collagen-degrading enzymes (cathepsin K and MMP9) and the growth factor FGF2. These findings suggest that efferocytosis by neutrophils drives macrophages toward an anti-inflammatory M2 phenotype, leading to immune evasion, ineffective fibrotic encapsulation, and parasitic growth. Given the wide distribution of cotton rats in the Americas and the expanding range of E. multilocularis, their hypersusceptibility raises significant public health concerns as rodents could serve as an intermediate host. These insights may inform new strategies for host-parasite interactions and the control of alveolar echinococcosis.

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proteins

2026-08-14 | Human leukocyte extract enhances albendazole efficacy against Echinococcus multilocularis in mice by reducing parasitic microRNAs, myeloid and lymphoid immunosuppressive cells.

Echinococcus multilocularis induces a serious zoonotic infection in humans and growth of metacestodes is associated with immunosuppression and tolerance. Current treatment relies almost exclusively on albendazole, a parasitostatic drug with variable clinical efficacy. Human low molecular weight leukocyte extract (HLE) has been shown to modulate innate and adaptive immunity at various diseases and can serve as promising and safe adjuvant to chemotherapy. In the present study we investigated the effects of albendazole (ABZ), human leukocyte extract (HLE) and their combination on murine alveolar echinococcosis, developing in the peritoneal cavities, by monitoring cysts weight, levels of circulating parasitic miRNAs, cytokine levels by ELISA and qPCR, the proportions of lymphoid and myeloid cells in spleens and peritoneal cavities by flow cytometry and proliferation of T and B lymphocytes and NO production ex vivo. Albendazole therapy moderately reduced cyst mass, selectively altered circulating parasite-derived miRNA levels in line with moderate decrease of IL-10 and TGF-β and myeloid-derived suppressor cells without the effects on suppressed T and B cells proliferation and high NO production. HLE in combination with ABZ significantly reduced peritoneal cyst growth and these two therapies markedly decreased circulating parasite derived microRNAs and expression of T- and B-regulatory cells lineage-specific transcription factors. These molecular changes were accompanied by a marked restoration of T and B lymphocyte proliferation, significant decline of regulatory IL-10 and TGF-β cytokines and immunosuppressive myeloid cells and MHC IIlow (M2) macrophages in spleens and peritoneal cavities, where HLE and ABZ + HLE interventions suppressed NO production and altered cytokine expression. The effect probably involved NF-κB downregulation, preventing excessive inflammation while enhancing ABZ efficacy. HLE as adjuvant enhanced albendazole efficacy against Echinococcus multilocularis infection in mice via reduction of T regulatoty type of response and MDSC expansion and shift of systemic and local immunity toward balanced Th1/Th2- biased profiles. The marked reduction in circulating parasite-derived miRNAs identifies a previously unrecognised mechanism that may contribute to the immunomodulatory effects of HLE and highlights these molecules as potential biomarkers of therapeutic response. Collectively, these results propose HLE as a promising adjunct immunotherapeutic candidate capable of counteracting parasite-induced immunosuppression and potentiating benzimidazole chemotherapy.

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2026-06-25 | Localization of the Complement C1q-Binding Site on Echinococcus multilocularis Calreticulin Identified by Peptide Mapping.

Alveolar echinococcosis is a life-threatening zoonotic parasitic disease caused by infection of Echinococcus multilocularis larvae. To survive within the host's immune milieu, E. multilocularis has evolved sophisticated immune evasion strategies, including the expression of immunomodulatory proteins that regulate the host immune response. Our previous studies have demonstrated that E. multilocularis calreticulin (EmCRT) possessed strong binding ability to human complement component C1q to inhibit C1q-initiated complement activation and biological functions. To further elucidate the mechanism by which EmCRT mediates C1q inactivation and immune evasion, the precise C1q-binding site on EmCRT was identified and analyzed in this study through expression of overlapping fragments and synthesis of overlapping peptides covering the identified functional fragment. The fragment expression and functional assay narrowed down the C1q-binding site to the EmCRT-S1 fragment located between amino acids 140 and 204 of EmCRT. The precise binding site was further pinpointed to the P5 peptide (EmCRT160-174 aa) by testing the synthetic peptides covering this region. The binding of peptide P5 to C1q markedly suppressed the activation of the C1q-mediated classical complement pathway and C1q-induced neutrophil chemotaxis, production of reactive oxygen species, cathepsin G, and myeloperoxidase. These findings suggest that the C1q-binding P5 peptide of EmCRT may serve as a potential target for the development of vaccines against echinococcosis or therapeutic drugs for complement-associated inflammatory or autoimmune diseases.

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2026-04-16 | The Interaction Between Echinococcus multilocularis Calreticulin S-Domain and Human Complement C1q Inhibits C1q-Dependent Immune Functions

EmCRT is a calreticulin secreted by Echinococcus multilocularis during its infection in host, playing an important role in evading host immune attack as a survival strategy. Our previous study has demonstrated that recombinant EmCRT (rEmCRT) was able to bind to C1q and lectin to interfere with host classical and lectin complement activation pathway, respectively. However, the C1q-binding site on EmCRT and the associated immune evasion mechanism remain unknown. In this study, the C1q-binding site on EmCRT was determined through molecular docking analysis and fragment expression to be localized to the S-domain (EmCRT-S) between Lys140 at the N-domain and Gln292 at the P-domain. The recombinant EmCRT-S protein (rEmCRT-S) was subsequently expressed in bacteria. Functional analysis confirmed that rEmCRT-S was able to bind to human C1q and inhibit C1q-initiated complement activation at the similar level to the full-length rEmCRT, resulting in the reduction in C4b/C3b deposition and antibody-sensitized sheep red blood cell hemolysis. Furthermore, rEmCRT-S binding to C1q suppressed THP-1-derived macrophage chemotaxis and ROS generation. Given that the identified functional domain EmCRT-S provides similar complement regulatory functions to the full-length EmCRT, this domain is a more feasible and practical target for vaccine development against E. multilocularis infection or for inflammatory and autoimmune diseases.

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2026-01-21 | IL-22-STAT3-CD155 axis in alveolar echinococcosis: a pivotal role in immune exhaustion and therapeutic potential.

Alveolar echinococcosis (AE), a lethal zoonosis caused by Echinococcus multilocularis (E.m) infection, is characterized by immune exhaustion that facilitates parasite evasion of host immunity and sustains chronic infection. The role and mechanisms of Interleukin-22 (IL-22), a key immunomodulatory cytokine, in E.m-induced immune responses remain unclear and warrant investigation. Liver tissue samples from AE patients and E.m-infected mouse models were utilized to investigate IL-22 expression dynamics during AE progression and its correlation with disease progression. Recombinant IL-22 (rIL-22) stimulation and IL-22-binding protein (rIL-22BP) blockade were integrated to comprehensively assess the role of IL-22 through Western blotting, immunohistochemistry (IHC), and enzyme-linked immunosorbent assay (ELISA). Pathological alterations in infected mice were quantified via hematoxylin and eosin (H&E) and Sirius Red staining to evaluate the potential of IL-22 as a therapeutic target. Flow cytometry and in vitro co-culture systems were further employed to identify the cellular sources of IL-22 and elucidate its regulatory effects on CD155 expression in hepatocytes. IL-22 expression was significantly upregulated in liver tissues from both AE patients and E.m-infected mice, positively correlating with disease progression. Compared with the infection group (Em), rIL-22 stimulation exacerbated parasitic burden, increasing lesion number and fibrotic area. Conversely, rIL-22BP blockade effectively attenuated pathology, significantly reducing lesion burden and fibrotic area. Mechanistically, in vitro co-culture experiments demonstrated that macrophage-derived IL-22 activated STAT3 signaling in hepatocytes, upregulating CD155 expression, which is a key mechanism underlying E.m-induced immune exhaustion. rIL-22BP treatment disrupted IL-22-CD155 intercellular crosstalk, promoting CD8+ T-cell recruitment to lesions and reversing their exhausted state. Our study demonstrates that the IL-22-STAT3-CD155 axis, mediated by macrophage-hepatocyte crosstalk, drives the establishment of an immune-exhaustive microenvironment during E.m infection. Mechanistically, macrophage-derived IL-22 induces CD155 upregulation in hepatocytes via IL-22RA1/STAT3 signaling. Critically, rIL-22BP blockade disrupts this axis, reversing the immunosuppressive cascade, restoring CD8+ T-cell effector functions, and remodeling the immune microenvironment. This intervention ultimately enhances host-mediated clearance of E.m.

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2025-06-11 | Activation of the Wnt signaling pathway and its role in epithelial-mesenchymal transition and hepatic fibrosis in alveolar echinococcosis.

This study examined the effects of Echinococcus multilocularis infection on the activation of the Wnt signaling pathway in hepatocytes, its association with epithelial-mesenchymal transition (EMT), and its role in E. multilocularis-induced hepatic fibrosis. Hepatic lesion tissues were obtained from 20 patients with clinically diagnosed alveolar echinococcosis (AE). These tissues were categorized into near-lesion and distant-from-lesion groups. Additionally, a murine model of AE infection was developed through the injection of E. multilocularis protoscoleces. The mice were divided into control, Wnt pathway enhancement (Wnt3a), and Wnt pathway inhibition (DKK1) groups. Four weeks post-infection, AAV-EGFP, AAV-Wnt3a-EGFP, or AAV-DKK1-EGFP vectors were administered, followed by tissue collection four weeks later. Both human and murine liver tissues were analyzed using Masson's trichrome, hematoxylin and eosin (H&E), and Sirius red staining, as well as immunohistochemical and western blot analyses to assess protein expression levels associated with EMT and fibrosis. Elevated expression levels of Wnt3a, β-catenin, N-cadherin, Col1a1, α-SMA, Vimentin, CTGF, and TGF-β were observed in tissues adjacent to human AE lesions and in the Wnt3a-treated mouse group. Conversely, E-cadherin expression was low. Immunohistochemical analysis demonstrated lower expression of Wnt3a, β-catenin, and other EMT- and fibrosis-related proteins in perilesional areas in human tissues and in the DKK1-treated mouse group, while increased E-cadherin expression was elevated. Inflammatory cell infiltration and fibrosis were observed near human lesions, whereas the DKK1-treated mouse group exhibited significantly reduced fibrosis. The Wnt signaling pathway plays a key role in the development of hepatic fibrosis associated with AE infection. Its activation is positively correlated with EMT and the increased expression of fibrogenic markers, including Collagen I, CTGF, and TGF-β, thereby contributing to the progression of hepatic fibrosis in hepatic AE.

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antibodies

2026-09-25 | PD-L1+ neutrophils at the invasive margin drive contact-dependent CD8+ T cell exhaustion in hepatic alveolar echinococcosis.

Hepatic alveolar echinococcosis (HAE), a lethal chronic helminth infection caused by Echinococcus multilocularis, is characterized by pronounced local immune evasion and progressive CD8+ T cell exhaustion at the parasite?host invasive margin. However, the spatial cellular network and core regulatory subsets driving this localizedimmunosuppression remainpoorly understood. We performed high-resolution spatial immune profiling of the lesion invasive margin (collagenous layer tissue, CLT) and paired distal normal liver tissues (DLT) from 12 HAE patients by integrating imaging mass cytometry, single-cell RNA sequencing, and multiplex immunofluorescence. The underlying molecular mechanism was validated via in vitro co-culture assays with or without Transwell physical separation, and the therapeutic potential was further confirmed in a delayed?treatment HAE mouse model using neutrophil depletion(anti-Ly6G) or PD-L1 blockade (anti-PD-L1). Spatial multi-omics identified a specific subset of APC-like PD-L1 neutrophils exclusively enriched at the HAE invasive margin, which showed striking spatial co-localization and frequent membrane-to-membrane contacts with PD-1 CD8 T cells. In vitro, activated CD8 Tcells potently induced PD-L1 upregulation on neutrophils; reciprocally, PD-L1 neutrophils significantly suppressed T cell effector function (downregulating GZMB, IFN-γ, and TNF-α) and upregulated exhaustion-associated transcription factors TOX and NR4A1 via a contact-dependent PD-L1/PD-1 pathway, effects largely abolished by Transwell separation. In the HAE mouse model, both neutrophil depletion and PD-L1 blockade significantly reduced parasite burden, alleviated liver inflammation and fibrosis, and restored CD8 T cell cytotoxicity; notably, neutrophil depletion achieved superior therapeutic efficacy compared with PD-L1 monotherapy. Collectively, our findings demonstrate that PD-L1-expressing neutrophils at the HAE invasivefront contribute importantly to localized CD8 T cell exhaustion via direct cell-cell contact, anddisrupting this crosstalk represents a promising targeted strategy to restore host protective immunity against parasitic infection.

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2026-06-17 | ST2 blockade modulates IL-33-driven immune responses and is associated with reduced hepatic fibrosis in alveolar echinococcosis.

Infection with Echinococcus multilocularis causes alveolar echinococcosis (AE), a severe parasitic disease characterised by progressive hepatic infiltration and fibrosis. Current treatment options remain limited, and the immune-mediated mechanisms underlying fibrosis are not fully understood. This study investigated the role of the IL-33/ST2 axis in AE-associated immunopathology and evaluated the effects of ST2 blockade in an experimental model. A murine model of AE was established in C57BL/6 mice, which were allocated to untreated infected, anti-ST2-treated infected and uninfected control groups. Liver pathology and fibrosis were assessed using haematoxylin and eosin staining, Masson's trichrome staining and transmission electron microscopy. Immune and fibrotic markers were analysed by immunohistochemistry and immunofluorescence. In parallel, liver samples from patients with AE were examined to evaluate translational relevance. Systemic cytokine profiles were quantified to assess immune modulation. Analysis of human AE liver samples showed an increased expression of IL-33/ST2 and associated immune and fibrotic markers, consistent with findings in the experimental mouse model. In infected mice, ST2 blockade significantly reduced metacestode lesion size and hepatic tissue invasion. This was accompanied by reduced fibrosis, as indicated by lower expression of α-smooth muscle actin, collagen I, matrix metalloproteinase-9 and tissue inhibitor of metalloproteinases-1. Anti-ST2 treatment was also associated with reduced hepatic infiltration of CD4⁺ T cells, B cells and M2 macrophages, along with decreased systemic levels of IFN-γ, TNF-α, IL-4, IL-13, IL-17 and IL-1β. ST2 blockade reduced metacestode growth and was associated with attenuated hepatic inflammation and fibrosis, supporting a role for IL-33/ST2 signalling in AE progression. Given the concurrent reduction in parasite burden, further studies are needed to determine whether the anti-fibrotic effects of ST2 inhibition are independent of parasite control.

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2026-05-25 | Imaging mass cytometry of the immune microenvironment in alveolar echinococcosis.

Alveolar echinococcosis (AE), caused by Echinococcus multilocularis, is a severe parasitic disease exhibiting tumor-like growth and profound immune evasion. The spatial organization and immunosuppressive mechanisms within the human AE lesion microenvironment remain poorly characterized. High-dimensional imaging mass cytometry (IMC) was performed on liver tissue sections from six patients with histologically confirmed AE, comparing lesion-proximal (close liver tissue, CLT) and lesion-distal (distant liver tissue, DLT) regions. This approach enabled simultaneous profiling of immune cell infiltration, spatial heterogeneity, immune checkpoint expression, and microenvironmental architecture. Complementary immunofluorescence and immunohistochemistry were used to evaluate age-related differences in neutrophil subsets between pediatric and adult patients. Sixteen immune cell types were resolved by IMC, revealing distinct spatial distributions: CD15- neutrophils and CD4+ effector memory T (Tem) cells accumulated in partially necrotic zones; M1/M2 macrophages and dendritic cells formed ring-like structures around cytotoxic T lymphocyte (CTL)-rich areas; CD4+ and CD8+ effector T cells exhibited dispersed circular patterns. M2 macrophages showed a negative correlation with T cells-suggesting T cell exhaustion-and a positive association with CD15+ neutrophils but not CD15-neutrophils. Immune checkpoint molecules were generally expressed at low levels in CLT, with focal PD-1/PD-L1 co-expression, broad CD47 distribution, rare NKG2A+ cells, and TIGIT enrichment in innate NK cells. Based on the TIMELASER classification system, the AE immune microenvironment was categorized into three subtypes: marrow-enriched immunosuppressive, stroma-enriched immunosuppressive, and immune-resident. Significantly higher densities of both CD15+ and CD15- neutrophils were observed in CLT of pediatric patients compared to adults. This study provides the first spatially resolved map of the immune landscape in human AE, revealing dynamic immunosuppressive niches shaped by myeloid-lymphoid crosstalk and checkpoint regulation. These findings offer new insights into early immune evasion mechanisms and potential targets for host-directed therapeutic strategies.

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2026-03-12 | The critical window for host defense: macrophage trogocytosis eliminates Echinococcus multilocularis at the early establishment stage

Introduction The ability of Echinococcus multilocularis (E.m) to establish infection depends on evading host immune clearance during the early stages. This study investigated the mechanisms by which host macrophages eliminate E.m during this critical window. Methods We utilized a mouse infection model with fluorescently labeled protoscoleces to observe early immune dynamics in vivo . Histopathological analysis was performed to characterize lesion phenotypes. The mechanism of parasite killing was further explored using in vitro co-culture experiments and scanning electron microscopy (SEM). Results Rapid immune cell infiltration and parasite clearance in the liver were observed within 24 hours post-infection. Histopathological analysis revealed two distinct lesion phenotypes: "Progressive Lesions," characterized by a failure of macrophage infiltration and parasite transformation into vesicles, and "Regressive Lesions," marked by high macrophage density and complete parasite elimination. In vitro experiments demonstrated that macrophages mediated protoscolex killing through complement-dependent trogocytosis, a process requiring active serum components. SEM confirmed direct macrophage-parasite contact and trogocytosis as the primary mode of elimination. Discussion These findings highlight the pivotal role of macrophage trogocytosis in early host defense against E.m infection and provide new insights into the mechanisms of innate immunity in parasitic clearance.

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2026-03-06 | CCR8 orchestrates an immunosuppressive niche in the liver to promote Echinococcus multilocularis infection.

Echinococcus multilocularis (E. m) infection causes alveolar echinococcosis (AE), a serious zoonotic disease characterized by invasive larval growth in the liver. The parasite establishes a chronic infection, suggesting effective modulation of host immunity. Here, we investigated the role of the CCR8/CCL1 chemokine axis in shaping the hepatic immune microenvironment during E.m infection. In infected wild-type (WT) mice, chronic infection specifically activated the hepatic CCR8/CCL1 axis, which was associated with a marked accumulation of FOXP3+ regulatory T cells (Tregs). Notably, although CCR8+ T cells expanded numerically, their production of effector (IFN-γ, TNF-α, and perforin) was significantly impaired. In contrast, infected CCR8-knockout (KO) mice developed smaller hepatic lesions, exhibited a reduction in liver weight, and had significantly lower serum ALT levels. Mechanistically, CCR8 deficiency enhanced the effector functions of CD4+ and CD8+ T cells, skewing the immune response towards a Th1 phenotype, and partially reversed the immunosuppressive milieu. Our findings establish that the CCR8/CCL1 axis drives the formation of an immunosuppressive niche in the liver by recruiting both Tregs and functionally suppressed CCR8+ T cells, thereby facilitating parasite immune evasion. This study not only elucidates a pivotal mechanism of immune escape in AE but also identifies CCR8 as a promising novel immunotherapeutic target for this neglected tropical disease.

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2026-08-24 | Cage-assembled antigenic particle vaccine (CAP-V) orchestrates coordinated antigen-responsive immunity and protection against alveolar Echinococcosis

Alveolar echinococcosis (AE) i s a life-threatening zoonotic disease caused by the larval stage of Echinococcus multilocularis ( E. multilocularis ). It is characterized by the tumor-like invasive growth pattern and limited treatment options. Although immunoprophylaxis represents a promising strategy, it is difficult to achieve sufficient immune activation without disrupting Th1/Th2 immune homeostasis. Here we report a cage-assembled antigenic particle vaccine (CAP-V) that leverages a self-assembling protein nanocage to elicit protective antiparasitic immunity. CAP-V is constructed using an engineered circularly permuted E2 (CPE2) scaffold to display the full-length E. multilocularis 14-3-3 antigen through either genetic fusion or post-assembly SpyCatcher–SpyTag conjugation. Both vaccine sequence formulations assemble into homogeneous nanoparticles and can be efficiently produced in Escherichia coli . Mechanistically, CAP-V induced BMDC maturation-associated responses and coordinated cellular and humoral immunity. In vivo immunization elicited concurrent Th1- and Th2-associated responses, with a comparatively stronger IFN-γ/IgG2c-associated component. Importantly, this coordinated immune profile is associated with significant protection against E. multilocularis challenge, reflected by reduced parasite burden and ameliorated tissue pathology. Together, these findings demonstrate Em14-3-3 CAP-Vs as a modular and mechanistically informed protein nanovaccine platform and highlight its potential for immunoprophylaxis against AE and other chronic helminthic diseases.

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2026-07-03 | A novel activation-related gene P158 is essential for evagination and early development of Echinococcus multilocularis protoscoleces.

Alveolar echinococcosis is a lethal zoonotic parasitic disease caused by Echinococcus multilocularis. The activation and subsequent evagination of protoscoleces (PSCs) in the host digestive tract are critical steps for establishing infection in definitive hosts, yet the underlying molecular mechanisms remain poorly understood. In this study, we employed an in vitro PSC activation model combined with transcriptomic analysis to identify activation-associated genes. A novel gene, designated P158, was further characterized by transcriptional unit analysis and functional knockdown assays to assess its role in PSC evagination, viability, tegument integrity, energy metabolism, and early metacestode development. We confirmed that P158 constitutes an independent transcriptional unit from the adjacent DDX1 gene of E. multilocularis and found that P158 expression was significantly upregulated following activation. Knockdown of P158 led to a significant reduction in PSC evagination rate and impaired metacestode vesicular development in vitro. Concurrently, decreased cellular viability and damage to the microtriches indicated compromised tegument structural integrity. Further mechanistic analysis showed that P158 knockdown triggered metabolic dysregulation, characterized by reduced ATP levels, shrinkage of glycogen storage cells, and depletion of intracellular glycogen reserves. These findings demonstrate that P158 plays an essential role in promoting PSC evagination and early development by maintaining tegument structural integrity and regulating energy metabolism homeostasis. This study highlights P158 as a potential target for interventions aimed at blocking parasite development at the definitive host stage.

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2026-04-18 | Tearing down the wall: emu-miR-745-3p in Echinococcus multilocularis exosomes attenuates host liver fibrosis to permit invasive lesion development.

Alveolar echinococcosis (AE), caused by Echinococcus multilocularis (E. multilocularis), exhibits tumor-like, invasive growth in the liver. Unlike cystic echinococcosis, AE lesions are often bordered by loose fibrosis rather than a dense fibrotic capsule. The mechanism by which the parasite attenuates this host fibrotic response remains unknown. We performed small RNA sequencing of parasite-derived exosomes (EmV-EXOs) and multi-step screening to identify functional miRNAs. The candidate was validated via bioinformatics, dual-luciferase assays, and in vitro studies in hepatic stellate cells (HSCs). An adeno-associated virus (AAV6)-delivered Tough Decoy (TuD) RNA was used for in vivo inhibition in a murine model. emu-miR-745-3p was identified as an exosomal miRNA enriched in EmV-EXOs. It is delivered to HSCs and directly targets the 3' UTR of dipeptidyl peptidase-4 (DPP4), a pro-fibrotic regulator. Downregulation of DPP4 suppressed HSCs activation, reducing expression of α-SMA, COL1A1, and TIMP1. In vivo inhibition of emu-miR-745-3p enhanced perilesional fibrosis, promoted a thicker fibrous capsule, and significantly reduced parasitic lesion burden. E. multilocularis employs exosomal emu-miR-745-3p to attenuate host fibrotic encapsulation, facilitating invasive growth. The emu-miR-745-3p/DPP4 axis is a critical determinant of AE pathology and a potential target for novel anti-fibrotic therapeutics.

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2026-02-22 | Exploration of the Role of the lncRNA MALAT1 in Hepatic Alveolar Echinococcosis by Regulating the miR-378c/IGF1R Axis Via High-throughput Sequencing

Background: Hepatic alveolar echinococcosis (HAE) is a severe parasitic disease with invasive growth characteristics similar to those of malignant tumors, and most patients cannot be cured by surgery. The drug treatment options are limited. Long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) play key regulatory roles in the progression of various diseases, including liver cancer. The functions of molecules such as lncRNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) and miR-378c in cancer have been widely reported, but their roles in HAE remain unclear. Objectives: This study aims to identify aberrant lncRNAs as diagnostic biomarkers for the progression of hepatic alveolar echinococcosis through RNA sequencing (RNA-seq), and to investigate the potential mechanisms underlying lncRNA dysregulation in the advancement of this disease. Methods: This paired-tissue study used RNA-seq (discovery set) on hepatic alveolar echinococcosis lesion tissues and matched adjacent liver tissues from three patients, followed by independent cohort validation by quantitative real-time polymerase chain reaction (qRT-PCR) (n = 20 for MALAT1 and insulin-like growth factor 1 receptor (IGF1R); n=13 for miR-378c). Lesion tissues from hepatic alveolar echinococcosis patients served as the experimental group, with adjacent tissues as controls. Metastasis-associated lung adenocarcinoma transcript 1 and IGF1R expression were further verified by qRT-PCR in lesion tissues and in liver tissues less than 1 cm and greater than 1 cm from the lesion. Meanwhile, miR-378c expression was assessed in a subset of patients. Potential binding sites among MALAT1, miR-378c, and IGF1R were predicted using StarBase and validated by dual-luciferase reporter assays. Results: A total of 914 significantly differentially expressed lncRNAs were screened by RNA-seq in three samples of hepatic alveolar echinococcosis lesion tissues and adjacent tissues. Quantitative real-time polymerase chain reaction verification revealed that MALAT1 and IGF1R were highly expressed and that the level of miR-378c was low in hepatic alveolar echinococcosis lesions. A dual-luciferase assay revealed that MALAT1 targeted miR-378c and miR-378c targeted IGF1R in the three cases of hepatic alveolar echinococcosis. Differential expression was analyzed using DESeq2 with Benjamini–Hochberg false discovery rate (FDR) correction (FDR < 0.05, |fold change (FC)| > 2). In the validation cohort, qRT-PCR confirmed that MALAT1 and IGF1R were significantly upregulated whereas miR-378c was significantly downregulated in lesion tissues (P < 0.05). Correlation analysis showed that MALAT1 was negatively associated with miR-378c and positively associated with IGF1R, and miR-378c was negatively associated with IGF1R. Conclusions: LncRNA MALAT1 may be involved in the progression of hepatic alveolar echinococcosis by acting as a molecular sponge for miR-378c and regulating the expression of the downstream target gene IGF1R.

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2026-02-17 | Protoscolex Maturation in Echinococcus multilocularis Is Controlled by Host Genetic Factors Independent of Initial Development.

Alveolar echinococcosis, caused by Echinococcus multilocularis, poses a serious public health concern. This parasite requires rodents as intermediate hosts for protoscolex maturation in the liver and subsequent transmission to definitive hosts. We aimed to identify the host genetic factors controlling protoscolex development and maturation in congenic mice carrying susceptible DBA/2 genomic segments on a resistant C57BL/6N background. We assessed the hepatic protoscoleces and immune-related gene expression levels 16 weeks post-oral infection. All congenic strains developed protoscoleces; however, the number and proportion of mature forms decreased as C57BL/6N-derived genomic contribution on chromosome 1 increased. Differences in DBA/2-derived segments revealed two loci, E. multilocularis protoscolex maturation 1 (Empmat1) and 2 (Empmat2), as regulators of protoscolex maturation, but not early development, where immune involvement was limited. T-box transcription factor 21 expression was correlated with protoscolex maturation; however, it lay outside Empmat1 and Empmat2 and was unlikely to be the responsible gene. Therefore, protoscolex maturation is potentially regulated by multiple host genetic factors distinct from those involved in early development, with B6-derived alleles exerting inhibitory effects, possibly via non-immune host mechanisms. Elucidation of these genetic pathways can reveal novel targets to disrupt the life cycle and reduce the zoonotic transmission of E. multilocularis.

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