Response patterns in adventitial layer of Echinococcus granulosus sensu stricto cysts from naturally infected cattle and sheep

γδ T cell distribution in the adventitial layer of non-fertile cystic echinococcosis cysts from cattle livers

Cystic Echinococcosis (CE) is a zoonotic disease caused by Echinococcus granulosus sensu lato, forming cysts in ruminants and humans with major health and economic impacts. The immune response to CE cysts is complex, with fertility linked to the host's inflammatory reaction. This study examines γδ T cell distribution and role within the adventitial layer of non-fertile CE cysts in cattle, including cases co-infected with the trematode Fasciola hepatica (FH), a known immune response modulator. Using immunohistochemistry and double immunofluorescence, we observed γδ T cells dispersed in the adventitial layer, enriched in inflammatory zones. Co-infected cases (CE + FH+) showed a reduced γδ T cell proportion among CD3+ T cells compared to non-coinfected cases, suggesting an immunoregulatory effect of FH. Our findings align with prior studies showing γδ T cell recruitment in granulomatous diseases in ruminants but reveal that co-infection alters this response. This study provides the first detailed characterization of γδ T cells in cattle CE cysts, emphasizing their potential role in granulomatous immune responses. It highlights the need for further research into mechanisms influencing CE cyst fertility and immune modulation in helminth co-infections, advancing our understanding of host-pathogen interactions and informing disease management strategies.

Echinococcus granulosus-Induced Liver Damage Through Ferroptosis in Rat Model

(1) Background: Cystic echinococcosis (CE) is an Echinococcus granulosus-induced worldwide parasitic zoonosis and is a recognized public health and socio-economic concern. The liver is the major target organ for CE's infective form protoscolex (PSCs), which causes serious liver damage and endangers the host's life. Reports show that PSC infection causes liver cell Fe2+ metabolism disorder and abnormal deposition of Fe2+ in liver cells and results in liver cell death. However, whether PSC-induced liver cell death is associated with ferroptosis remains to be clarified. (2) Methods: Using both an in vivo rat model and an in vitro co-culture of PSCs and the cell system, we studied the histopathological progress of PSCs infection and the cytopathogenesis of PSC-induced cell death in the liver. Hepatic-injury-related ferroptosis signaling pathways were identified by proteomics analysis at various stages of PSCs infection, and physiological and the biochemical indexes and expression of pathway proteins related to hepatic ferroptosis were studied. Ferrostatin-1, a ferroptosis inhibitor, was employed for in vivo interference with early protoscolices infection in rats, and the effects of the inhibition of hepatocyte ferroptosis on hepatocyte injury and the generation of fibrotic cysts were investigated. Additionally, PSCs were exposed to in vitro co-culture with BRL, a rat hepatocyte line, to clarify the direct influences of PSCs on BRL ferroptosis. (3) Results: The results of our in vivo studies revealed that PSCs infection induced Fe2+ enrichment in liver cells surrounding the PSCs cysts, cellular oxidation, and liver tissue damage along with the prolongation of PSCs parasitism. The results of our in vitro studies verified the ability of PSCs to directly induce ferroptosis, the formation of fibrotic cysts, and alteration of the iron metabolism of liver cells. The analysis of KEGG signaling pathways revealed that ferroptosis- and ROS-related pathways were significantly induced with PSCs infection. Using Ferrostatin-1 effectively blocked ferroptosis, reversed Fe2+ content, reduced liver cell oxidation, and reduced PSC-induced fibrosis cysts. (4) Conclusions: Our study reveals the histopathological progress of PSC infection and the cytopathogenesis of PSC-induced ferroptosis. Ferrostatin-1 effectively blocked PSCs infection and PSC-induced cell death in vivo and in vitro. Accordingly, the inhibition of PSC-induced hepatocyte ferroptosis may be an effective method in the control of Echinococcus granulosus infection and should be seriously considered in clinical studies.

Zoonotic threat of cystic echinococcosis in Tunisia: insights into livestock prevalence and identification of the G1 genotype

Introduction

Cystic echinococcosis (CE) is a zoonosis caused by the larval stage of the Echinococcus granulosus sensu lato (s.l.) complex. CE is globally distributed, with a particularly high prevalence in North African countries, especially Tunisia. Despite its significant public health impact and the economic burden it places on livestock production, recent data on CE prevalence in Tunisian livestock remain scarce. This study aimed to assess the prevalence of CE in livestock, investigate potential differences across host species, and identify risk factors contributing to the CE transmission dynamics.

Methods

The study was conducted in two governorates located in the North-Eastern region of Tunisia. A multidimensional approach included post-mortem inspection of slaughtered animals, fertility and viability analyses of the isolated CE cysts, and molecular genotyping of the parasite was conducted.

Results and discussion

A total of 21,487 animals were examined, 15.86% of the sheep and 9.57% of the cattle were infected with at least one CE cyst, with females showing higher prevalence rates. No CE cases were detected in goats or dromedaries. In all infected animals, the infection rate increased with the age of the host. CE cysts were predominantly found in both the liver and lung of the same animal in sheep and cattle. Aborted lesions were the most common stage of infection, and multiple CE cysts were frequently observed in affected animals. Fertile CE cysts were highly prevalent in both sheep and cattle, with rates increasing with host age, confirming the critical role of sheep in the parasite transmission cycle and demonstrating that cattle in Tunisia also play a significant role in the propagation of CE. Molecular analysis confirmed the predominance of the zoonotic G1 genotype of E. granulosus sensu stricto. This is particularly concerning as the G1 genotype is also the most common genotype affecting humans. This underscores a strong zoonotic potential and highlights the need for integrated control strategies. The findings emphasize the role of the livestock-dog cycle in CE transmission, posing risks to humans living near infected animals. Effective measures, including slaughter regulations, dog deworming, public education, and enhanced veterinary surveillance within a One Health approach, are essential for reducing CE's impact on human and animal health.

HLA class II profile in patients with different stages of cystic echinococcosis according to the WHO ultrasound imaging classification

The factors involving in the natural history and determinants of different features of human cystic echinococcosis (CE) are not adequately understood. Several host-related factors including the genetic structure of the host and human leukocyte antigens (HLAs) are believed to be involved in the natural history of CE in humans. The present study was conducted to investigate the association between HLA class II genes and active and inactive stages of hepatic cystic echinococcosis. Echinococcus granulosus cyst samples and patient information were collected from the biobank of the Iranian Hydatid Disease Registry from 2019 to 2022. HLA-DRB and HLA-DQB were characterized by PCR method. CE patients were categorized into three active (CE1 and CE2), inactive (CE4 and CE5), and transitional (CE3) stages according to the WHO ultrasound classification of CE. In total, 77 participants including 38 patients (36.8% men and 63.2% women) with different stages of CE as well as 39 healthy individuals (38.5% men and 61.5% women) were included in the study. Findings of the study showed that the frequency of HLA-DRB1*03 was significantly lower in the patients compared to the healthy individuals. The frequencies of HLA-DQB and HLA-DRB alleles were not differed significantly between active, inactive, and transitional stages of E. granulosus cysts. Findings of this study indicate the potential role of this allele in the susceptibility of human to cystic echinococcosis. Further large-scale studies in different endemic countries are required to document the significance of HLA-DQB and HLA-DRB as a host-related factor in the natural history of CE in human.

Comparative analysis of host immune responses to Hydatid cyst in human and ovine hepatic cystic Echinococcosis

BACKGROUND

Hydatid disease is caused by the larval stages of the canine tapeworm Echinococcus granulosus. It is one of the most critical helminthic diseases, representing worldwide public health and socio-economic concern.

AIM

This study aimed to investigate the expression of apoptosis and immune response within hepatic tissues of humans and sheep infected with the Hydatid cyst.

METHODS

Paraffin-embedded tissue was prepared from each tissue sample and used for histopathological examination by Haematoxylin- Eosin. Also, toluidine blue staining was used for mast cell detection, while an immunohistochemical study was performed to assess CD3 T lymphocytes, CD4 helper T lymphocytes, CD8 cytotoxic T lymphocytes, CD20 memory B lymphocytes, CD68 macrophage, and caspase-3 antibodies.

RESULTS

The histological examination revealed significant changes, including the infiltration of inflammatory cells, predominantly lymphocytes with scattered giant cells, necrotic hepatic tissue, and fibrosis. Toluidine blue stain revealed a higher number of mast cells (5 cells/field) in humans compared to sheep (3.6 cells/field). The immunohistochemical analysis confirmed that the CD3 were the most predominant inflammatory cell in the hepatic tissue of humans (intensive 70%), and sheep (moderate 38.47%). Caspase-3 was observed in all samples in different grades and mostly in human liver tissue.

CONCLUSION

This data could aid in recognizing immunological markers for differentiating disease progression, as well as enhance the understanding of local immune responses to cystic Echinococcosis (CE). The findings could provide preliminary data for future studies on immune responses associated with Hydatid cysts.

Assessment of oxidative stress and tissue damage in Echinococcus granulosus naturally infected bovine liver

Echinococcus granulosus is a zoonotic parasite infects many livestock species, especially cattle, sheep, goat and buffalo, causing cystic echinococcosis. The aim of this study was to demonstrate the presence of the parasite and parasitic tissue damage histopathologically and to determine the role of oxidative stress in the tissue damage through the immunohistochemical detection of the oxidative damage-marker malondialdehyde (MDA) and the antioxidant response-marker superoxide dismutase (SOD). The material of the study consisted of 20 liver samples with Echinococcus cysts and 10 E.granulosus- negative healthy liver samples obtained from different cattle at various times from slaughterhouses in Kırıkkale province, Turkey. Histopathologically, Echinococcus cysts of various sizes were observed along with the surrounding fibrous connective tissue. Giant cells, mononuclear cells, and eosinophilic leukocytes were found between the fibrous connective tissue and the cyst. In the parenchymal tissue distant from the cyst, inflammatory changes were observed, including vacuolation and necrosis in hepatocytes, congestion and dilation sinusoidal capillaries. Immunohistochemically, MDA immunopositivity was observed in both hepatocytes surrounding the cyst and areas distant from the cyst, while SOD immunopositivity was mainly detected in fibrous connective tissue and hepatocytes surrounding the Echinococcus cysts. A significant increase in MDA immunoreactivity was observed in E.granulosus s.l.-infected livers. Although no statistically significant change was observed in SOD immunopositivity in the liver tissues with cystic echinococcosis, regional variations were noted. Germinal layer (GL) of Echinococcus cyst showed immunopositive staining for MDA, while laminated layer (LL) exhibited immunonegative staining. To the authors' best understanding, this study represents a pioneering effort in showcasing and evaluating the immunoreactivities of MDA and SOD within the liver tissue afflicted with Echinococcus cysts. Simultaneously, the examination extends to encompass tissue damage and the infiltration of inflammatory cells. This study highlights the role of oxidative stress in the pathogenesis of Cystic Echinococcosis (CE) and the need for further investigation of antioxidant defense mechanisms and their regional variations.

Weighted gene co-expression network analysis reveals immune evasion related genes in Echinococcus granulosus sensu stricto

Cystic echinococcosis (CE) is a zoonotic disease caused by the tapeworm Echinococcus granulosus sensu lato (s.l). In the intermediate host, this disease is characterized by the growth of cysts in viscera such as liver and lungs, inside of which the parasite develops to the next infective stage known as protoscoleces. There are records that the infected viscera affect the development and morphology of E. granulosus s.l. protoscolex in hosts such as buffalo or humans. However, the molecular mechanisms that drive these differences remains unknown. Weighted gene co-expression network analysis (WGCNA) using a set of RNAseq data obtained from E. granulosus sensu stricto (s.s.) protoscoleces found in liver and lung cysts reveals 34 modules in protoscoleces of liver origin, of which 12 have differential co-expression from protoscoleces of lung origin. Three of these twelve modules contain hub genes related to immune evasion: tegument antigen, tegumental protein, ubiquitin hydrolase isozyme L3, COP9 signalosome complex subunit 3, tetraspanin CD9 antigen, and the methyl-CpG-binding protein Mbd2. Also, two of the twelve modules contain only hypothetical proteins with unknown orthology, which means that there are a group of unknown function proteins co-expressed inside the protoscolex of liver CE cyst origin. This is the first evidence of gene expression differences in protoscoleces from CE cysts found in different viscera, with co-expression networks that are exclusive to protoscoleces from liver CE cyst samples. This should be considered in the control strategies of CE, as intermediate hosts can harbor CE cysts in liver, lungs, or both organs simultaneously.

microRNAs in parasite-induced liver fibrosis: from mechanisms to diagnostics and therapeutics

Chronic parasite infections in the liver pose a global threat to human and animal health, often occurring with liver fibrosis that leads to cirrhosis, liver failure, and even cancer. Hepatic fibrogenesis is a complex yet reversible process of tissue repair and is associated with various factors, including immune cells, microenvironment, gut microbiome, and interactions of the different liver cells. As a profibrogenic or antifibrogenic driver, microRNAs (miRNAs) are closely involved in parasite-induced hepatic fibrosis. This article updates the current understanding of the roles of miRNAs in hepatic fibrogenesis by parasite infections and discusses the strategies using miRNAs as candidates for diagnostics and therapeutics.

Detection of Echinococcus granulosus sensu lato cysts and seroprevalence of cystic echinococcosis in cattle and camels in Maiduguri Abattoir

Cystic echinococcosis (CE) is a zoonotic disease of great importance worldwide. This study was conducted to determine the prevalence and antigenic profile of Echinococcus cysts (CE cysts) in camels and cattle. The lungs, livers, hearts, and kidneys of 560 animals, comprising 304 camels and 256 cattle slaughtered in the Maiduguri abattoir, were examined for CE. Blood samples were collected for serology. Protein profiles of CE fluids were analyzed using indirect Enzyme Linked Immunosorbent Assay while Sodium Dodecyl Sulphate Polyacrylamide Gel Electrophoresis (SDS-PAGE) was used to characterize the electrophoretic pattern of different CE cyst fluid samples. The overall prevalence of CE was 8.4%, 14.14% (95% CI = 10.65-18.54%) in camels and 1.60% (95% CI = 0.46-4.09%) in cattle. Adult camels 41 (16.21%) (95% CI = 12.15-21.27%) had a higher prevalence than the young camels 2 (3.92%) (95% CI = 0.33-13.97%) (p = 0.038). In cattle, only adults 4 (2.0%) had cysts. Higher prevalence of CE was recorded in male 22 (16.42%) (95% CI = 11.03-23.68%) than female 21 (12.35%) (95% CI = 8.16-18.21%) camels [p = 0.399] while only female cattle 3 (2.2%) had cysts. Higher prevalence of CE was recorded in the livers of 34 (11.18%) (95% CI = 8.08-15.25%) than in the lungs 25 (8.22%) (95% CI = 5.59-11.90%) of camels [p = 0.273]. Of the 47 cysts collected, 43 (91.49%) and 4 (8.51%) were from camels and cattle, respectively. A total of 18 (38.30%) fertile, 17 (36.17%) non-fertile, and 12 (25.53%) calcified cysts were recovered in animals. Overall seroprevalence of 52.63% (95% CI = 47.02-58.18%) and 35.55% (95% CI = 29.93-41.59%) were observed in camels and cattle in this study. The SDS-PAGE of camel CE cyst fluids revealed protein bands at 64kda, 91kda, 160kda, and 200kda molecular units while the purified cyst fluids revealed bands at 64kda, 91kda, 120kda, 160kda, and 200kda. Regular meat inspections and the exclusion of dogs from abattoir premises are strongly encouraged. Investigation into local prevailing factors encouraging transmission should be carried out.

Transcriptome analysis of Echinococcus granulosus sensu stricto protoscoleces reveals differences in immune modulation gene expression between cysts found in cattle and sheep

Cystic Echinococcosis (CE), a zoonotic parasitic disease, is caused by the cestode Echinococcus granulosus sensu lato. CE inflicts severe damage in cattle, sheep, and human hosts worldwide. Fertile CE cysts are characterized by the presence of viable protoscoleces. These parasite forms are studied with minimal contamination with host molecules. Hosts, cattle and sheep, show differences in their CE cyst fertility. The effect of the host in protoscolex transcriptome is not known. We genotyped and performed transcriptomic analysis on sheep protoscoleces obtained from liver and lung CE cysts. The transcriptomic data of Echinococcus granulosus sensu stricto protoscoleces from 6 lung CE cysts and 6 liver CE cysts were Collected. For host comparison analysis, 4 raw data files belonging to Echinococcus granulosus sensu stricto protoscoleces from cattle liver CE cysts were obtained from the NCBI SRA database. Principal component and differential expression analysis did not reveal any statistical differences between protoscoleces obtained from liver or lung cysts, either within the same sheep or different sheep hosts. Conversely, there are significant differences between cattle and sheep protoscolex samples. We found differential expression of immune-related genes. In cattle, 7 genes were upregulated in protoscoleces from liver cysts. In sheep, 3 genes were upregulated in protoscoleces from liver and lung CE cysts. Noteworthy, are the differential expression of antigen B, tegument antigen, and arginase-2 in samples obtained from sheep CE cysts, and basigin in samples from cattle CE cysts. These findings suggest that the host species is an important factor involved in the differential expression of immune related genes, which in turn is possibly related to the fertility of Echinococcus granulosus sensu stricto cysts.

Metabolomics Analysis of Splenic CD19+ B Cells in Mice Chronically Infected With Echinococcus granulosus sensu lato Protoscoleces

Background: The larval stages of Echinococcus granulosus sensu lato (E. granulosus s.l) infection can alter B cell function and affect host anti-infective immunity, but the underlying mechanism remains unclear. The newly emerging immunometabolism highlights that several metabolites are key factors in determining the fate of immune cells, which provides a new insight for exploring how larval E. granulosus s.l. infection remodels B cell function. This study investigated the metabolomic profiles of B cells in mice infected with E. granulosus s.l. protoscoleces (PSC).

Results:Total CD19⁺ B cells, purified from the spleen of infected mice, showed significantly increased production of IL-6, TNF-α, and IL-10 after exposure to LPS in vitro. Moreover, the mRNA expression of metabolism related enzymes in B cells was remarkably disordered post infection. In addition, differential metabolites were identified in B cells after infection. There were 340 differential metabolites (83 upregulated and 257 downregulated metabolites) identified in the positive ion model, and 216 differential metabolites (97 upregulated and 119 downregulated metabolites) identified in the negative ion mode. Among these, 64 differential metabolites were annotated and involved in 68 metabolic pathways, including thyroid hormone synthesis, the metabolic processes of glutathione, fructose, mannose, and glycerophospholipid. Furthermore, several differential metabolites such as glutathione, taurine, and inosine were validated to regulate the cytokine production in LPS stimulated B cells.

Conclusion:Infection with the larval E. granulosus s.l. causes metabolic reprogramming in the intrinsic B cells of mice, which provides the first evidence for understanding the role and mechanism of B cells in parasite anti-infective immunity from the viewpoint of immunometabolism.