Immunology of cystic echinococcosis (hydatid disease)

The expression of CTLA-4 in hepatic alveolar echinococcosis patients and blocking CTLA-4 to reverse T cell exhaustion in Echinococcus multilocularis-infected mice

Alveolar echinococcosis (AE) is a zoonotic parasitic disease caused by the infection of Echinococcus multilocularis (E. multilocularis) larvae. Cytotoxic T-lymphocyte antigen 4 (CTLA-4) produces inhibitory signals and induces T cell exhaustion, thereby inhibiting the parasiticidal efficacy of the liver immune system. Therefore, the purpose of this study is to explore how T-cell exhaustion contributes to AE and whether blocking CTLA-4 could reverse T cell exhaustion. Here we discovered that the expression of CTLA-4 was increased in the infiltrating margin around the lesion of the liver from AE patients by using western blot and immunohistochemistry assay. Multiple fluorescence immunohistochemistry identified that CTLA-4 and CD4/CD8 molecules were co-localized. For in vitro experiments, it was found that the sustained stimulation of E. multilocularis antigen could induce T cell exhaustion, blocking CTLA-4-reversed T cell exhaustion. For in vivo experiments, the expression of CTLA-4 was increased in the liver of E. multilocularis-infected mice, and the CTLA-4 and CD4/CD8 molecules were co-localized. Flow cytometry analysis demonstrated that the percentages of both CD4+ T cells and CD8+ T cells in the liver and peripheral blood were significantly increased and induced T exhaustion. When the mice were treated with anti-CTLA-4 antibodies, the number and weight of the lesions decreased significantly. Meanwhile, the flow cytometry results suggested that blocking CTLA-4 could effectively reverse T cell exhaustion and reactivate immune function. Our work reveals that blocking CTLA-4 could effectively reverse the T cell exhaustion caused by E. multilocularis and could be used as a novel target for the treatment of AE.

Concomitant Polymyalgia Rheumatica and Giant Cell Arteritis Associated with Cystic Echinococcosis: A Rare Geriatric Case

INTRODUCTION

Parasitic infections could be an important triggering factor for autoimmune diseases. We present a clinical case of concomitant polymyalgia rheumatica (PMR) and giant cell arteritis (GCA) induced with cystic echinococcosis (CE).

CASE PRESENTATION

A 74-year-old male was admitted with a 2-month history of progressive pain at the shoulders and hip, movement restriction, and constitutional symptoms. As a result of the examinations performed due to rheumatological complaints, PMR and GCA were diagnosed. The cystic appearance, which was incidentally detected in the liver 6 months ago and not examined at that time, was found to be hydatid cyst. Medical treatment was initiated for all three conditions and the patient's symptoms improved significantly.

DISCUSSION

Parasite infections may cause various autoimmune diseases because of molecular mimicry or sustained immune activation. Echinococcus granulosus is a very complex multicellular parasite and highly immunogenic for humans. Some body parts of the parasite, the outer surface and secreted particles, stimulate the host immune system strongly.

CONCLUSION

The first case in the literature of coexistence of PMR and GCA associated with CE. Autoimmune diseases should be evaluated in patients with CE. Furthermore, CE should be considered in patients with autoimmune diseases in the presence of a cyst.

Safety of Three-Dimensional Conformal Radiotherapy on the Sheep with Pulmonary Cystic Echinococcosis: A Preliminary Study

PURPOSE

Radiotherapy showed the potential to effectively kill the cysts of pulmonary cystic echinococcosis (CE). However, little is known about its safety. This study was designed to investigate the safety of three-dimensional conformal radiotherapy (3D-CRT) on the normal lung tissue adjacent to the cyst and blood of sheep naturally infected with pulmonary CE.

METHODS

Twenty pulmonary CE sheep were randomly divided into control group (n = 5) and radiation groups with a dose of 30 Gray (Gy) (n = 5), 45 Gy (n = 5), and 60 Gy (n = 5), respectively. Animals in control group received no radiation. Heat shock protein 70 (Hsp70), tumor growth factor-β (TGF-β), matrix metalloproteinase-2 (MMP-2) and MMP-9 in the lung tissues adjacent to the cysts, which were considered to be closely related to the pathogenesis of CE, were evaluated after 3D-CRT. A routine blood test was conducted.

RESULTS

The results showed that there were multiple cysts of various sizes with protoscoleces in the lung tissues of sheep, and necrotic cysts were found after 3D-CRT. 3D-CRT significantly increased the mRNA level of Hsp70, enhanced the protein level of TGF-β and slightly increased the expression of MMP-2 and MMP-9 in lung tissues adjacent to the cysts. 3D-CRT did not significantly alter the amount of WBC, HB and PLT in sheep blood.

CONCLUSIONS

The results suggested that 3D-CRT may suppress the inflammation and induce less damage of the normal lung tissues and blood. We preliminarily showed that 3D-CRT under a safe dose may be used to treat pulmonary CE.

Characterization of the immunosuppressive environment induced by larval Echinococcus granulosus during chronic experimental infection

The larval stage of Echinococcus granulosus causes the chronic infection known as cystic echinococcosis, deploying strong inhibitory mechanisms on host immune responses. Using experimental intraperitoneal infection in C57BL/6 mice, we carried out an in-depth analysis of the local changes in macrophage populations associated with chronic infection. In addition, we analyzed T cells and relevant soluble mediators. Infected animals showed an increase in local cell numbers, mostly accounted for by eosinophils, T cells, and macrophages. Within macrophage populations, the largest increases in cell numbers corresponded to resident large peritoneal macrophages (LPM). Monocyte recruitment appeared to be active, as judged by the increased number of monocytes and cells in the process of differentiation towards LPM, including small (SPM) and converting peritoneal macrophages (CPM). In contrast, we found no evidence of macrophage proliferation. Infection induced the expression of M2 markers in SPM, CPM, and LPM. It also enhanced the expression of the co-inhibitor PD-L1 in LPM, SPM, and CPM and induced the co-inhibitor PD-L2 in SPM and CPM. Therefore, local macrophages acquire M2-like phenotypes with probable suppressive capacities. Regarding T cells, infection induced an increase in the percentage of CD4+ cells that are PD-1+, which represent a potential target of suppression by PD-L1+/PD-L2+ macrophages. In possible agreement, CD4+ T cells from infected animals showed blunted proliferative responses to in vitro stimulation with anti-CD3. Further evidence of immune suppression in the parasite vicinity arose from the observation of an expansion in FoxP3+ CD4+ regulatory T cells and increases in the local concentrations of the anti-inflammatory cytokines TGF-β and IL-1Ra.

Echinococcus granulosus cyst fluid inhibits inflammatory responses through inducing histone demethylase KDM5B in macrophages

BACKGROUND

Echinococcus granulosus cyst fluid (EgCF) weakens macrophage inflammatory responses, thereby enabling the parasite to evade the immune system. However, the role of histone modification in this process remains to be explored.

METHODS

The levels of IL-6, TNF-α, IL-10, H3K4me3, and KDM5B were detected using quantitative real-time PCR, ELISA, and Western blotting. The enrichment of H3K4me3 and KDM5B at the promoter of inflammatory factors was detected by chromatin immunoprecipitation.

RESULTS

Based on EgCF-stimulated macrophage models, we found that EgCF significantly inhibited mRNA expression and protein secretion of IL-6 and TNF-α and upregulated mRNA expression of IL-10 under the influence of TLR4. EgCF lowered the level of H3K4me3 and promoted the transcription and protein stability of histone demethylase KDM5B. Chromatin immunoprecipitation analysis revealed that EgCF suppressed the enrichment of H3K4me3 modification at the promoters of TNF-α and IL-6 and downregulated their expression in macrophages. Additionally, the inhibition of KDM5B activity by CPI-455 weakened the anti-inflammatory effect of EgCF.

CONCLUSIONS

Our findings demonstrate a novel mechanism through which EgCF promotes KDM5B expression and inhibits the enrichment of H3K4me3 at the promoters of inflammatory cytokines to suppress the inflammatory response.

Characterisation of extracellular vesicles isolated from hydatid cyst fluid and evaluation of immunomodulatory effects on human monocytes

Hydatidosis is a disease caused by the larval stage of Echinococcus granulosus, which involves several organs of intermediate hosts. Evidence suggests a communication between hydatid cyst (HC) and hosts via extracellular vesicles. However, a little is known about the communication between EVs derived from HC fluid (HCF) and host cells. In the current study, EVs were isolated using differential centrifugation from sheep HCF and characterized by western blot, electron microscope and size distribution analysis. The uptake of EVs by human monocyte cell line (THP-1) was evaluated. The effects of EVs on the expression levels of pro- and anti-inflammatory cytokines were investigated using quantitative real-time PCR (RT-PCR), 3 and 24 h after incubation. Moreover, the cytokine level of IL-10 was evaluated in supernatant of THP-1 cell line at 3 and 24 h. EVs were successfully isolated and showed spherical shape with size distribution at 130.6 nm. After 3 h, the expression levels of pro-inflammatory cytokine genes (IL1Β, IL15 and IL8) were upregulated, while after 24 h, the expression levels of pro-inflammatory cytokines were decreased and IL13 gene expression showed upregulation. A statistically significant increase was seen in the levels of IL-10 after 24 h. The main mechanism of the communication between EVs derived from HCF and their host remains unclear; however, time-dependent anti-inflammatory effects in our study suggest that HC may modulate the immune responses via EVs.

Mucins Shed from the Laminated Layer in Cystic Echinococcosis Are Captured by Kupffer Cells via the Lectin Receptor Clec4F

Cystic echinococcosis is caused by the larval stages (hydatids) of cestode parasites belonging to the species cluster Echinococcus granulosus sensu lato, with E. granulosus sensu stricto being the main infecting species. Hydatids are bladderlike structures that attain large sizes within various internal organs of livestock ungulates and humans. Hydatids are protected by the massive acellular laminated layer (LL), composed mainly of mucins. Parasite growth requires LL turnover, and abundant LL-derived particles are found at infection sites in infected humans, raising the question of how LL materials are dealt with by the hosts. In this article, we show that E. granulosus sensu stricto LL mucins injected into mice are taken up by Kupffer cells, the liver macrophages exposed to the vascular space. This uptake is largely dependent on the intact mucin glycans and on Clec4F, a C-type lectin receptor which, in rodents, is selectively expressed in Kupffer cells. This uptake mechanism operates on mucins injected both in soluble form intravenously (i.v.) and in particulate form intraperitoneally (i.p.). In mice harboring intraperitoneal infections by the same species, LL mucins were found essentially only at the infection site and in the liver, where they were taken up by Kupffer cells via Clec4F. Therefore, shed LL materials circulate in the host, and Kupffer cells can act as a sink for these materials, even when the parasite grows in sites other than the liver.

Can Echinococcus granulosus-Derived MicroRNAs be Biomarkers for Diagnosis and Follow-up of Cystic Echinococcosis Patients?

INTRODUCTION

Cystic echinococcosis (CE) is a neglected tropical disease caused by the larval stages of Echinococcus granulosus (E. granulosus). MicroRNAs (miRNAs) are small noncoding RNAs acting as mediators in host-parasite interaction. Recently, numerous studies have been conducted on miRNAs in infectious diseases; however, little data are available about the role of miRNAs in pathogenesis and early diagnosis of CE.

METHODS

The current study evaluated the expression of four E. granulosus-derived miRNAs, including egr-miR-125,5p, egr-let-7,5p, egr-miR-2, and egr-miR-71 in fibrotic and healthy liver tissues of 31 CE patients with active and inactive hydatid cysts by qRT-PCR.

RESULTS

Of the 31 patients, 48.4% had active cysts (CE1 and CE2), while the remainder had transitional (16.1%) and inactive (35.5%) CE types cysts. The qRT-PCR analysis revealed a significant increase of 11.2, 9.91, 6.2, and 13.1-fold in the fibrotic tissue group for egr-miR-125,5p, egr-let-7,5p, egr-miR-2, and egr-miR-71, respectively. Among these miRNAs, egr-miR-125-5p exhibited the highest area under the curve (AUC) value of 0.8050 for predicting liver fibrosis.

CONCLUSIONS

Our findings provide new data about the role of E. granulosus-derived miRNAs in pathogenesis of CE. The high AUC of egr-miR125,5p reflecting the possibility of using egr-miR125,5p as biomarker in CE diagnosis. Further studies on serum of CE patients are needed to confirm the potential role of circulating egr-miR-2a-3p and egr-miR-125-5p in the early diagnosis of CE.

Serum Level of egr-miR-2a-3p as a Potential Diagnostic Biomarker for Cystic Echinococcosis

INTRODUCTION

Cystic Echinococcosis (CE) is a chronic parasitic disease caused by the metacestodes of Echinococcus granulosus senso lato (E. granulosus s.l.). The larval stages of this parasite, hydatid cyst, are usually diagnosed using imaging modalities and serological testing; however, several studies have recently suggested using the parasite-derived microRNAs (miRNAs) as novel diagnostic biomarkers.

MATERIALS AND METHODS

The present study included 31 CE patients who were older than 5 years and were admitted to the hospitals of Ahvaz, Iran for hydatid cyst removal surgery during 2019-2021. The egr-miR-125-5p and egr-miR-2a-3p levels were evaluated in the sera of the CE patients before and 6 months after the surgery using Quantitative Real-Time PCR (qRT-PCR), and the results were compared with the serum samples from 15 healthy volunteers. Then, the intergroup comparisons were performed using the t test.

RESULTS

The patients' age range was 6-72 years, with a mean age of 34.6 years. Moreover, based on the classification by the WHO-IWGE, one patient (3.2%) had CE1, 14 patients (45.2%) had CE2, 5 patients (16.1%) had CE3, 2 patients (6.5%) had CE4, and 9 patients (29%) had CE5. Also, 21 patients (67.74%) had a positive antigen test using the ELISA method, while 10 patients (32.26%) had a negative ELISA. The pre-operative expression level of egr-miR-2a-3p was 10.36 folds higher compared to 6 months after the surgery, with an AUC value of 0.8176. However, the expression levels of egr-miR-125-5p did not change significantly 6 months after the surgery compared to pre-operative levels.

CONCLUSIONS

According to the present study results, the serum levels of egr-miR-2a-3p can be a promising non-invasive biomarker for diagnosing CE and monitoring its potential recurrence after cystectomy.

Clinical characteristics and antibodies against Echinococcus granulosus recombinant antigen P29 in patients with cystic echinococcosis in China

Objectives

Cystic echinococcosis (CE) is a neglected parasitic zoonotic disease caused by the larval stage of the tapeworm Echinococcus granulosus (E. granulosus). This study aimed to understand the clinical characteristics of human CE in Ningxia Hui Autonomous Region (NHAR) located in northwest China and to investigate the antibody profiles against the recombinant E. granulosus antigen P29 (rEg.P29) in plasma of CE patients.

Methods

A total of 37 human CE patients, along with 37 healthy donors enrolled in this study and demographic and clinical data were analyzed, including age, gender, laboratory data, symptoms, and cysts description. Plasma levels of cytokines, total IgG, and total IgE were determined by sandwich ELISA kits. Specific antibodies against rEg.P29 and hydatid cyst fluid (HCF) were assessed by indirect ELISA.

Results

The results revealed that females have a higher percentage of CE patients than males. The incidence of CE reached a peak in the 41–50 years-old group. The liver was the most frequent location, accounting for 91.9%. Based on the CT images, cysts of 34 patients who had liver involvement, were classified as 1 (2.9%) CE1, 12 (35.3%) CE2, 5 (14.7%) CE3a, 1 (2.9%) CE3b, and 15 (44.2%) CE5. Twenty-nine (78.4%) patients had a single cyst and 8 (21.6%) had at least two cysts. The most frequently reported symptom was upper abdominal pain. The plasma level of IL-6 and total IgE were significantly increased in CE patients compared with healthy donors. Additionally, IgG response to rEg.P29 in CE patients was significantly higher than in healthy donors, and the dominant IgG subclass was IgG4. Further analysis of different patient groups revealed that rEg.P29-specific IgG and IgG4 were only elevated in CE patients with CE2 type cysts.

Conclusions

This study systematically investigated the clinical characteristics of patients with CE and may provide a reference basis for the diagnosis and treatment of CE in NHAR. Furthermore, tests of specific IgG and IgG4 against rEg.P29 can be used as an assisted method for imaging techniques to identify cystic activity and determine the best therapeutic approach for CE.

The Role of Tissue Inhibitor of Metalloproteinase-1 and 2 in Echinococcus granulosus senso lato-Induced Human Hepatic Fibrosis

INTRODUCTION

The main mechanism underlying hepatic fibrosis is the imbalance between tissue Matrix Metalloproteinases (MMPs) and Tissue Inhibitors of Metalloproteinases (TIMPs). This study aimed to investigate the potential role of TIMP-1 and TIMP-2 in the process of hepatic fibrosis caused by Echinococcus granulosus senso lato (E. granulosus s.l.).

METHODS

The expressions levels of TIMP-1 and TIMP-2 mRNAs were evaluated in fibrotic and normal hepatic tissues of 30 patients with Cystic Echinococcus (CE) using qRT-PCR. Moreover, their serum levels of TIMP-1 were assessed before CE cyst removal and 6 months after surgery using ELISA.

RESULTS

The qRT-PCR results showed that the expression levels of TIMP-1 and TIMP-2 mRNAs were significantly higher in the fibrotic hepatic tissue compared to the normal liver tissue, in a way that the TIMP-1 and TIMP-2 mRNA expression levels were 19.07 and 6.58 folds higher in the fibrotic tissue compared to the normal liver tissue. Among these TIMPs, TIMP-1 exhibited the higher area under the curve (AUC) value for predicting liver fibrosis. However, we could not find a significant difference in the serum levels of TIMP-1 before and after the cyst removal procedure (p = 0.48).

CONCLUSIONS

For the first time, our study showed that the significant overexpression of both TIMP mRNAs in the fibrotic liver tissue of the CE patients may be due to the increased expression of MMPs in the peri-cystic tissue. However, we could not find a significant difference in the pre- and post-operative TIMP-1 levels, which may be due to recurrence or heterogeneity in the cyst type. Therefore, performing further studies with a larger sample size of the CE patients is recommended.

Retrospective Determination of the Prevelense of Anti-Echinococcus granulosus Antibodies in Cystic Echinococcosis Pre-diagnosed Patients at Erciyes University Faculty of Medicine

OBJECTIVE

Cystic echinococcosis (CE) is a parasitic disease that has been known for years in helminth diseases and it is important as human and animal health problem in many parts of the world and in our country due to economic losses. In this study, it was aimed to retrospectively evaluate the distribution of anti-E. granulosus-IgG antibodies in patients with pre-diagnosis of CE that referred to parasitology laboratory between January 2013-December 2018.

METHODS

Commercial kit was used for indirect hemaglutination (IHA), indirect fluorescent antibody test (IFAT) and Western blot (WB) methods using sera from patient samples was applied according to the kit proposal. In addition, patient materials for CAM, CSF and blood for which polymerase chain reaction (PCR)/QPCR tests were requested were examined.

RESULTS

Sera of the patients who were tested with at least one of the IHA, IFAT and WB methods or a combination of these methods, and 443 cases out of 2.283 cases were found to be E. granulosus seropositive. It was determined that 369 (62.03%) of 443 positive patients were female and 330 (37.97%) were male patients. Among these patients, 87 patients whose IFAT and/or IHA tests were negative were found to have positive results with the WB method. IFAT or IHA test results of 13 patients with negative WB tests were found to be positive. Four patients were identified with both tests positive but WB test results negative. In addition, 36 of 72 patients who underwent PCR/QPCR tests were found to be positive.

CONCLUSION

As a result of a six-year retrospective screening, 22% of the cases were found to be positive, and it was concluded that the prevalence of CE is high and the use of a single test may be insufficient in the diagnosis of CE, therefore, test combinations will increase the sensitivity and reliability in reaching the correct diagnosis.

Expression profiling of exosomal miRNAs derived from different stages of infection in mice infected with Echinococcus granulosus protoscoleces using high-throughput sequencing

Echinococcosis is a worldwide zoonosis. The mechanism of the establishment, growth, and persistence of parasites in the host has not been fully understood. Exosomes are found to be a way of information exchange between parasites and hosts. They exist in various body fluids widely. There are few studies on host-derived exosomes and their miRNA expression profiles at different infection time points. In this study, BALB/c mice were intraperitoneally infected with protricercariae. Exosomes were extracted from plasma (0, 3, 9, and 20 weeks post infection), and the expression profiles of exosome miRNA in the peripheral blood of mice were determined using RNA-sequencing. Compared to the 0 week groups, 24, 35, and 22 differentially expressed miRNAs were detected in infected mouse at the three infection stages, respectively. The results showed that there were significant differences in the miRNAs of exosomes at different infection time points. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were used to annotate the different miRNAs. The results showed that the biological pathways of parasites changed significantly at different stages of infection, with many significant and abundant pathways involved in cell differentiation, inflammation, and immune response, such as MAPK signaling pathway, Th17 cell differentiation, Wnt signaling pathway, FoxO signaling pathway, Notch signaling pathway, etc. These results suggest that miRNA may be an important regulator of interactions between Echinococcus granulosus and host. The data provided here provide valuable information to increase understanding of the regulatory function of microRNAs in the host microenvironment and the mechanism of host-parasite interaction. This may help us to find targets for Echinococcus granulosus to escape host immune attack and control Echinococcus granulosus infection in the future.

The Recombinant Eg.P29-Mediated miR-126a-5p Promotes the Differentiation of Mouse Naive CD4+ T Cells via DLK1-Mediated Notch1 Signal Pathway

Cystic echinococcosis (CE) is a zoonotic parasitic disease spread worldwide caused by Echinococcus granulosus (Eg), which sometimes causes serious damage; however, in many cases, people are not aware that they are infected. A number of recombinant vaccines based on Eg are used to evaluate their effectiveness against the infection. Our previous report showed that recombinant Eg.P29 (rEg.P29) has a marvelous immunoprotection and can induce Th1 immune response. Furthermore, data of miRNA microarray in mice spleen CD4⁺ T cells showed that miR-126a-5p was significantly elevated 1 week after immunization by using rEg.P29. Therefore, in this perspective, we discussed the role of miR-126a-5p in the differentiation of naive CD4⁺ T cells into Th1/Th2 under rEg.P29 immunization and determined the mechanisms associated with delta-like 1 homolog (DLK1) and Notch1 signaling pathway. One week after P29 immunization of mice, we found that miR-126a-5p was significantly increased and DLK1 expression was decreased, while Notch1 pathway activation was enhanced and Th1 response was significantly stronger. The identical conclusion was obtained by overexpression of mmu-miR-126a-5p in primary naive CD4⁺ T cells in mice. Intriguingly, mmu-miR-126a-5p was significantly raised in serum from mice infected with protoscolex in the early stages of infection and markedly declined in the late stages of infection, while has-miR-126-5p expression was dramatically reduced in serum from CE patients. Taken together, we show that miR-126a-5p functions as a positive regulator of Notch1-mediated differentiation of CD4⁺ T cells into Th1 through downregulating DLK1 in vivo and in vitro. Hsa-miR-126-5p is potentially a very promising diagnostic biomarker for CE.

Proteomic Analysis of Plasma-Derived Extracellular Vesicles From Mice With Echinococcus granulosus at Different Infection Stages and Their Immunomodulatory Functions

The globally distributed cystic echinococcosis (CE) is caused by the larval stage of Echinococcus granulosus (E. granulosus), a cosmopolitan and zoonotic disease with potentially life-threatening complications in humans. The emerging roles for extracellular vesicles (EVs) in parasitic infection include transferring proteins and modifying host cell gene expression to modulate host immune responses. Few studies focused on the host-derived EVs and its protein profiles. We focused on the EVs from mouse infected with E. granulosus at different stages. ExoQuick kit was used for isolating EVs from mouse plasma and ExoEasy Maxi kit was used for isolating protoscolex culture supernatant (PCS) and hydatid cyst fluid (HCF). Firstly, EVs were characterized by transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA) and immunoblot. Secondly, the proteins of plasma EVs were identified using liquid chromatography-tandem mass spectrometry (LC–MS/MS). The resulting LC–MS/MS data were processed using Maxquant search engine (v 1.5.2.8). Tandem mass spectra were researched against the mice and E. granulosus proteins database in the NCBI. The differentially expressed proteins are performed by proteomic label-free quantitative analysis and bioinformatics. Thirdly, in vitro experiment, the results of co-culture of plasma EVs and spleen mononuclear cells showed that 7W-EVs can increase the relative abundance of regulatory T (Treg) cells and IL-10. We further verified that EVs can be internalized by CD4⁺ and CD8⁺ T cells, B cells, and myeloid-derived suppressor cells (MDSC). These results implied host-derived EVs are multidirectional immune modulators. The findings can contribute to a better understanding of the role of host-derived EVs which are the optimal vehicle to transfer important cargo into host immune system. In addition, we have found several important proteins associated with E. granulosus and identified in infected mouse plasma at different stages. Furthermore, our study further highlighted the proteomics and immunological function of EVs from mouse infected with E. granulosus protoscoleces at different infection stages. We have laid a solid foundation for the role of EVs in cystic echinococcosis in the future research and supplemented a unique dataset for this E. granulosus.

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.

The Correlation Between Platelet-to-Lymphocyte Ratio and Neutrophil-to-Lymphocyte Ratio with Hepatic Echinococcosis

Objective

To explore the correlation between neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) with hepatic hydatid diseases.

Methods

The clinical data of 420 patients with hydatid disease who were treated in our hospital from October 2015 to October 2018 were collected from the database of our hospital. According to the postoperative pathological diagnosis, 200 patients were assigned into the alveolar echinococcosis (AE) group, and 220 patients were assigned into the cystic echinococcosis (CE) group. A total of 160 healthy examinees were enrolled as the control group. The main observation indexes included preoperative PLR and NLR. Pearson's correlation was used to analyze the correlation between PLR and NLR with clinical indicators in HE patients, and the receiver operator characteristic (ROC) curve was used to evaluate the clinical values of PLR and NLR in diagnosing different types of hydatid diseases.

Results

The results revealed that the expressions of PLR and NLR were significantly higher in the AE group than in the CE and control groups (P<0.05). The results of multiple linear regression analysis revealed that PLR was positively correlated with aspartate aminotransferase, alanine aminotransferase, total bilirubin, direct bilirubin, alkaline phosphatase and γ-glutamyltranspeptidase (P<0.05). NLR was correlated with albumin content (P<0.05). ROC curve analysis results revealed that the area under the curve (AUC) of PLR and NLR for AE was 0.800 and 0.700 respectively, and the AUC for CE was 0.78 and 0.75 respectively.

Conclusion

The NLR and PLR of AE patients were higher than those of CE patients, and the high inflammation of CE patients may be correlated to the reproductive mode of Echinococcus multilocularis. PLR and NLR have certain diagnostic values for disease classification, but PLR has higher specificity when compared with NLR.

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

Cystic echinococcosis is a zoonotic disease caused by the metacestode of Echinococcus granulosus sensu lato. The disease is characterized by the development of cystic structures inside viscera of the intermediate host, mainly liver and lungs. These cysts are formed by three layers: germinal, laminated, and adventitial layer, the latter being the local host immune response. Metacestodes that develop protoscoleces, the infective stage to the definitive host, are termed fertile, whereas cysts that do not produce protoscoleces are termed non-fertile. Sheep usually harbor fertile cysts while cattle usually harbor non-fertile cysts. Adventitial layers with fibrotic resolution are associated to fertile cysts, whereas a granulomatous reaction is associated with non-fertile cysts. The aim of this study was to analyze cellular distribution in the adventitial layer of fertile and non-fertile E. granulosus sensu stricto cysts found in liver and lungs of cattle and sheep. A total of 418 cysts were analyzed, 203 from cattle (8 fertile and 195 non-fertile) and 215 from sheep (64 fertile and 151 non-fertile). Fertile cysts from cattle showed mixed patterns of response, with fibrotic resolution and presence of granulomatous response in direct contact with the laminated layer, while sheep fertile cysts always displayed fibrotic resolution next to the laminated layer. Cattle non-fertile cysts display a granulomatous reaction in direct contact with the laminated layer, whereas sheep non-fertile cysts display a granulomatous reaction, but in direct contact with the fibrotic resolution. This shows that cattle and sheep cystic echinococcosis cysts have distinct local immune response patterns, which are associated to metacestode fertility.

MiR-374b-5p Regulates T Cell Differentiation and Is Associated with rEg.P29 Immunity

Cystic echinococcosis (CE) is a zoonotic disease caused by Echinococcus granulosus (Eg) infection. Our previous study confirmed that recombinant Eg.P29 (rEg.P29) could protect against echinococcus granulosus secondary infection in sheep and mice. The aim of the study was to investigate the association between immunoprotection of rEg.P29 vaccine and mmu-miR-374b-5p (miR-374b-5p) and study the immunity influence of miR-374b-5p on CD4⁺ T cells in mice spleen. MiR-374b-5p level was significantly increased after the second-week and the fourth week of vaccination with rEg.P29. Overexpression of miR-374b-5p increased IFN-γ, IL-2, IL-17A mRNA levels and decreased IL-10 mRNA levels in CD4⁺ T cells. Moreover, the inhibition of miR-374b-5p decreased IFN-γ and IL-17A and increased IL-10 mRNA levels in CD4⁺ T cells; this was further confirmed by the flow cytometry. The vaccination of rEg.P29 enhanced miR-374b-5p expression that was associated with a higher Th1 and Th17 immune response, a lower IL-10 mRNA production with miR-374b-5p overexpression, a lower Th1 immune response, and a higher IL-10 mRNA levels with miR-374b-5p inhibitions. To sum up, these data suggest that miR-374b-5p may participate in rEg.P29 immunity by regulating Th1 and Th17 differentiation.

Microarray Analysis of lncRNA and mRNA Reveals Enhanced Lipolysis Along With Metabolic Remodeling in Mice Infected With Larval Echinococcus granulosus

Parasitic infection improves metabolic homeostasis in “western diet”-induced obesity through the regulation of adipogenesis. However, the underlying mechanism is not yet fully understood. Using microarray analysis, this study investigated the long non-coding RNA (lncRNA) and messenger RNA (mRNA) profiles of subcutaneous adipose tissues from mice infected with Echinococcus granulosus protoscoleces. A total of 1052 mRNA (541 upregulated, 511 downregulated) and 220 lncRNA (126 upregulated, 94 downregulated) transcripts were differentially expressed (fold change ≥2, P < 0.05) in the infected subcutaneous adipose tissues. When compared with the control group, the infected mice showed a decrease in adipose tissue mass and a reduction in adipocyte size. Indirect calorimetry revealed the change in the energy metabolism after infection, characterized by a lower CO₂ production and O₂ consumption, a sharp decline in carbohydrate oxidation, and a slight increase in fat oxidation. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses showed that the parasitic infection reprogrammed a complex metabolic network. Notably, “lipoxygenase” and “arginine and proline metabolism” pathways were significantly upregulated while “glycolysis,” “tricarboxylic acid cycle,” “de novo lipogenesis,” and “lipid droplet” pathways were dramatically downregulated. In addition, several key lncRNAs were associated with insulin resistance and adipocyte differentiation. Overall, the present study suggested that E. granulosus infection could enhance lipolysis. Thus, our findings provide novel insights into parasite-mediated metabolic homeostasis, and into the mechanism of hypertrophic adipocytes in obesity.

Activation of the NLRP3 Inflammasome by Particles from the Echinococcus granulosus Laminated Layer

The interaction of dendritic cells and macrophages with a variety of rigid noncellular particles triggers activation of the NLRP3 inflammasome and consequent secretion of interleukin 1β (IL-1β). Noncellular particles can also be generated in the context of helminth infection, since these large pathogens often shed their outermost structures during growth and/or molting. One such structure is the massive, mucin-based, soft, flexible laminated layer (LL), which protects the larval stages of cestodes of the genus Echinococcus.

The interaction of dendritic cells and macrophages with a variety of rigid noncellular particles triggers activation of the NLRP3 inflammasome and consequent secretion of interleukin 1β (IL-1β). Noncellular particles can also be generated in the context of helminth infection, since these large pathogens often shed their outermost structures during growth and/or molting. One such structure is the massive, mucin-based, soft, flexible laminated layer (LL), which protects the larval stages of cestodes of the genus Echinococcus. We show that particles from the Echinococcus granulosus LL (pLL) trigger NLRP3- and caspase-1-dependent IL-1β in lipopolysaccharide (LPS)-primed mouse bone marrow-derived dendritic cells (BMDC). This response can be elicited by pLL too large for phagocytosis and nonetheless requires actin dynamics, Syk, and phosphatidylinositol 3-kinase (PI3K). These three requirements had already been observed in our previous study on the alteration by pLL of CD86, CD40, IL-10, and IL-12 responses to LPS in BMDC; however, we now show that these alterations are independent of NLRP3 and caspase-1. In other words, an initial interaction with particles requiring actin dynamics, Syk, and PI3K, but not phagocytosis, elicits both NLRP3-dependent and NLRP3-independent responses. Intraperitoneal injection of pLL induced IL-1β, suggesting that contact with LL materials induces IL-1β in the E. granulosus infection setting. Our results extend our understanding of NLRP3 inflammasome activation by noncellular particulate materials both to helminth-derived materials and to flexible/soft materials.

Multiplex cytokine and antibody profile in cystic echinococcosis patients during a three-year follow-up in reference to the cyst stages

Background

Cystic echinococcosis (CE) is a worldwide parasitic zoonosis caused by infection of the larval stage of tapeworm Echinococcus granulosus. In human CE, the parasites develop and form cysts in internal organs. The differentiated cysts can be classified into five types based on WHO-IWGE standard CE1-5 representing different developmental stages. Infection with E. granulosus triggers hosts’ humoral and cellular response, displaying elevated serum antibodies and Th1 and Th2 cytokines, which are presumed to be in association with the disease outcome. Identification of immunological markers for evaluation of disease progression has been a growing concern. However, the distinctive profile of cytokines and antibodies associated with the cyst progression has not been ascertained.

Methods

To better understand the interaction between host immune response and disease outcome, the present study followed-up four CE patients over three years by yearly measuring serum level of 27 cytokines, total IgG and isotypes, and ultrasound scanning, beginning in year 1 for all patients with CE1 and CE2 cysts before treatment and continued in year 2 with CE4 and in year 3 with CE3-CE5 post-treatment.

Results

Nine cytokines including Th1-type IL-2, Th17-type IL-17A, and inflammatory cytokines IL-1β, IL-1Rα and TNF-α, chemokines IL-8, MIP-1α, MIP-1β, and growth factor G-CSF were significantly elevated in patients with cyst type CE1, compared to the normal controls, and then declined to a normal level at CE4 and CE5. Examining the antibody production, we found that serum specific IgG was significantly increased in patients with active and transitional cysts, specifically the total IgG at CE1/CE3/CE4-CE5, IgG4 at CE1 and IgG1 at CE1/CE3 cyst status, in comparison with the normal controls, but showed no significant changes between the cyst stages.

Conclusions

Our findings provide new information on the profile of multiplex cytokines and serum antibodies associated with cyst stages in cystic echinococcosis patients through a three-year follow-up, implying that further studies using an approach combining cyst-associated immune parameters may aid in identifying immunological markers for differentiation of disease progression.

Cell-mediated and humoral immune profile to hydatidosis among naturally infected farm animals

Background and Aim

Cystic echinococcosis (CE) is a widespread parasitic disease caused by Echinococcus granulosus tapeworm infect different intermediate hosts including sheep, cattle, and camels. The intermediate host's immune response to the hydatid cyst is still conflict and complex. The current study was designed to evaluate the immune response in sera of hydatid naturally infected sheep, cattle, and camels in the form of features of inflammatory cell infiltrations, levels of Th1 and Th2 cytokines, besides the humoral specific immunoglobulin G (IgG) responses.

Materials and Methods

Thirty-nine sheep, 74 cattle, and 79 camels' sera were collected and considered as CE naturally infected and ten samples from each species were graded as non-infected. Lung specimens were collected for histopathological examination. The quantitative concentrations of tumor necrosis factor-α, interleukin (IL)-6, IL-4, and IL-10 were determined. Different antigens were prepared from hydatid cyst; hydatid cyst fluid of lung origin hydatid cyst fluid of liver origin, hydatid cyst protoscoleces of lung origin (HCP-g), hydatid cyst protoscoleces of liver origin, hydatid cyst germinal layer of lung origin, and hydatid cyst germinal layer of liver origin; and characterized by gel electrophoresis and Western blotting analysis. The total specific IgG level against E. granulosus infection was measured using an indirect enzyme-linked immunosorbent assay.

Results

The results indicated that the cellular immune response in the infected tissues was characterized by inflammatory cell penetration. The pro-inflammatory Th1 cytokine profile was predominant in infected animals in comparison with non-infected ones. However, the humoral immune response was seen as a high level of IgG in infected animals. The presented data approved that the HCP-g antigen could be considered as a delegate antigen for all other prepared antigens with an immunoreactive band at molecular weights 32 kDa.

Conclusion

This study provides a fundamental insight into the events that manipulate cellular and humoral immune profiles in an intermediate host; sheep, cattle, and camel that naturally infected with CE. Hence, it was concluded that CE is a constant disease and confirm the reactivity Th1 in combating hydatid cyst. Besides, it could lead to the activation of the humoral immune response in the form of a high level of IgG.

Interactions between hydatid cyst and regulated cell death may provide new therapeutic opportunities

Cystic echinococcosis and alveolar echinococcosis are chronic zoonotic infections, transmitted throughout the world. Development of the cestode larval stages in the liver and lungs causes damage to intermediate hosts, including humans. Several pathways leading to the suppression of host immune response and the survival of the cysts in various hosts are known. Immune response modulation and regulated cell death (RCD) play a fundamental role in cyst formation, development and pathogenesis. RCD, referring to apoptosis, necrosis and autophagy, can be triggered either via intrinsic or extrinsic cell stimuli. In this review, we provide a general overview of current knowledge on the process of RCD during echinococcosis. The study of interactions between RCD and Echinococcus spp. metacestodes may provide in-depth understanding of echinococcosis pathogenesis and open new horizons for human intervention and treatment of the disease.

Particles from the Echinococcus granulosus Laminated Layer Inhibit CD40 Upregulation in Dendritic Cells by Interfering with Akt Activation

The larval stage of the cestode Echinococcus granulosus causes cystic echinococcosis in humans and livestock. This larva is protected by the millimeter-thick, mucin-based laminated layer (LL), from which materials have to be shed to allow parasite growth. We previously reported that dendritic cells (DCs) respond to microscopic pieces of the mucin gel of the LL (pLL) with unconventional maturation phenotypes, in the absence or presence of Toll-like receptor (TLR) agonists, including lipopolysaccharide (LPS).

The larval stage of the cestode Echinococcus granulosus causes cystic echinococcosis in humans and livestock. This larva is protected by the millimeter-thick, mucin-based laminated layer (LL), from which materials have to be shed to allow parasite growth. We previously reported that dendritic cells (DCs) respond to microscopic pieces of the mucin gel of the LL (pLL) with unconventional maturation phenotypes, in the absence or presence of Toll-like receptor (TLR) agonists, including lipopolysaccharide (LPS). We also reported that the presence of pLL inhibited the activating phosphorylation of the phosphatidylinositol 3-kinase (PI3K) effector Akt induced by granulocyte-macrophage colony-stimulating factor or interleukin-4. We now show that the inhibitory effect of pLL extends to LPS as a PI3K activator, and results in diminished phosphorylation of GSK3 downstream from Akt. Functionally, the inhibition of Akt and GSK3 phosphorylation are linked to the blunted upregulation of CD40, a major feature of the unconventional maturation phenotype. Paradoxically, all aspects of unconventional maturation induced by pLL depend on PI3K class I. Additional components of the phagocytic machinery are needed, but phagocytosis of pLL particles is not required. These observations hint at a DC response mechanism related to receptor-independent mechanisms proposed for certain crystalline and synthetic polymer-based particles; this would fit the previously reported lack of detection of molecular-level motifs necessary of the effects of pLL on DCs. Finally, we report that DCs exposed to pLL are able to condition DCs not exposed to the material so that these cannot upregulate CD40 in full in response to LPS.

Nanostructured lipid carriers of ivermectin as a novel drug delivery system in hydatidosis

Background

The larval stage of the tapeworm Echinococcus granulosus is the causative agent of hydatid disease in humans. This zoonotic parasitic infection remains a major health problem in certain areas of the world where is still endemic. In view of the ineffectiveness of some drug treatments, the surgical removal of cysts remains the preferred treatment option together with the administration of albendazole and mebendazole. However, severe side effects of these drugs have been reported which demands developing new scolicidal agents that confer suitable efficacy and fewer side effects during surgery.

Methods

To that purpose, in the present work we assessed the effectiveness of ivermectin (IVM), a macrocyclic lactone endectocide that has shown to be an effective nematocidal drug against other important parasitic infections. To overcome the limitations observed in some drug formulations and resistance, we used nano lipid carriers (NLCs) as a targeted and sustained drug delivery system for IVM. We evaluated the in vitro cestocidal and apoptotic effects of NLCs-loaded IVM versus IVM by quantifying the expression of caspase-3 mRNA.

Results

We found that after 60 and 120 min of administration, 800 μg/ml and 400 μg/ml NLCs-loaded IVM induced 100% mortality, respectively. On the other hand, the 800 μg/ml of IVM induced 100% mortality rate 150 min after administration. Additionally, we found that NLCs-loaded IVM induced higher mRNA caspase-3 expression suggesting a more potent apoptotic effect on the parasite.

Conclusions

These data suggest that NLCs-loaded IVM may be a promising alternative to current treatments although in vivo studies are needed.