New insights of the local immune response against both fertile and infertile hydatid cysts

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.

Evaluation of the Local and Peripheral Immune Responses in Patients with Cystic Echinococcosis

BACKGROUND

Cystic echinococcosis (CE) cysts may persist for decades because of immune modulation mechanisms. Here, we characterize the cysts and the blood immune responses in patients with CE.

METHODS

We enrolled 61 patients with CE and 19 control subjects. We received tissue samples from seven patients with CE and a control subject requiring liver cystectomy. The immunohistochemistry evaluation of the immune cell subtypes and cytokines in the pericysts and surrounding liver and the antigen B (AgB)-specific response analysis of whole blood were performed.

RESULTS

In CE, the pericyst and the surrounding liver parenchyma showed aggregates of CD3+ T lymphocytes, mainly CD4+. B lymphocyte aggregates were present in the liver tissue. Monocytes/granulocytes were rarely observed. Th2 cytokine expression was scarce, whereas IFN-γ expression was present in the CE tissues. The control subject did not show an inflammatory infiltrate. The IL-4-specific response to AgB was increased in the patients with CE compared to the control, and this result was confirmed in a larger cohort (p = 0.003), whereas the IFN-γ-response was similar between the two groups (p = 0.5570).

CONCLUSION

In patients with CE, CD4+ lymphocytes infiltrate the pericyst and the surrounding liver tissue with a low IL-4/IL-13 expression level and a moderate IFN-γ expression level; moreover, an IL-4 parasite-specific response is detected in the periphery. These results support adventitia involvement in CE immunopathogenesis.

Untargeted metabolomics to discriminate liver and lung hydatid cysts: Importance of metabolites involved in the immune response

The Echinococcus granulosus sensu lato species complex is responsible for the neglected zoonotic disease known as cystic echinococcosis (CE). Humans and livestock are infected via fecal-oral transmission. CE remains prevalent in Western China, Central Asia, South America, Eastern Africa, and the Mediterranean. Approximately one million individuals worldwide are affected, influencing veterinary and public health, as well as social and economic matters. The infection causes slow-growing cysts, predominantly in the liver and lungs, but can also develop in other organs. The exact progression of these cysts is uncertain. This study aimed to understand the survival mechanisms of liver and lung CE cysts from cattle by determining their metabolite profiles through metabolomics and multivariate statistical analyses. Non-targeted metabolomic approaches were conducted using quadrupole-time-of-flight liquid chromatography/mass spectrometry (LC-QTOF-MS) to distinguish between liver and lung CE cysts. Data processing to extract the peaks on complex chromatograms was performed using XCMS. PCA and OPLS-DA plots obtained through multiple statistical analyses showed interactions of metabolites within and between groups. Metabolites such as glutathione, prostaglandin, folic acid, and cortisol that cause different immunological reactions have been identified both in liver and lung hydatid cysts, but in different ratios. Considering the differences in the metabolomic profiles of the liver and lung cysts determined in the present study will contribute research to enlighten the nature of the cyst and develop specific therapeutic strategies.

Echinococcus granulosus ubiquitin-conjugating enzymes (E2D2 and E2N) promote the formation of liver fibrosis in TGFβ1-induced LX-2 cells

BACKGROUND

Cystic echinococcosis (CE) is a widespread zoonosis caused by the infection with Echinococcus granulosus sensu lato (E. granulosus s.l.). CE cysts mainly develop in the liver of intermediate hosts, characterized by the fibrotic tissue that separates host organ from parasite. However, precise mechanism underlying the formation of fibrotic tissue in CE remains unclear.

METHODS

To investigate the potential impact of ubiquitin-conjugating enzymes on liver fibrosis formation in CE, two members of ubiquitin-conjugating (UBC) enzyme of Echinococcus granulosus (EgE2D2 and EgE2N) were recombinantly expressed in Escherichia coli and analyzed for bioinformatics, immunogenicity, localization, and enzyme activity. In addition, the secretory pathway and their effects on the formation of liver fibrosis were also explored.

RESULTS

Both rEgE2D2 and rEgE2N possess intact UBC domains and active sites, exhibiting classical ubiquitin binding activity and strong immunoreactivity. Additionally, EgE2D2 and EgE2N were widely distributed in protoscoleces and germinal layer, with differences observed in their distribution in 25-day strobilated worms. Further, these two enzymes were secreted to the hydatid fluid and CE-infected sheep liver tissues via a non-classical secretory pathway. Notably, TGFβ1-induced LX-2 cells exposed to rEgE2D2 and rEgE2N resulted in increasing expression of fibrosis-related genes, enhancing cell proliferation, and facilitating cell migration.

CONCLUSIONS

Our findings suggest that EgE2D2 and EgE2N could secrete into the liver and may interact with hepatic stellate cells, thereby promoting the formation of liver fibrosis.

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.

Evolution of the Major Components of Innate Immunity in Animals

Innate immunity is present in all animals. In this review, we explore the main conserved mechanisms of recognition and innate immune responses among animals. In this sense, we discuss the receptors, critical for binding to pathogen-associated molecular patterns (PAMPs) or danger-associated molecular patterns (DAMPs); the downstream signaling proteins; and transcription factors that govern immune responses. We also highlight conserved inflammatory mediators that are induced after the recognition of DAMPs and PAMPs. At last, we discuss the mechanisms that are involved in the regulation and/or generation of reactive oxygen species (ROS), influencing immune responses, like heme-oxygenases (HOs).

Does the expression of granzyme B participate in inflammation, fibrosis, and fertility of hydatid cysts?

Echinococcus granulosus (sensu lato), a cestode that is endemic in Egypt, causes cystic echinococcosis (CE), a significant but neglected zoonotic disease that is prevalent throughout the world. Infected hydatid cysts are classified as fertile or non-fertile based on the presence of protoscoleces; nevertheless, the mechanism of non-fertile CE cysts remains unknown. The study aimed to assess whether granzyme B (GrB) expression and CD4 + /CD8 + could be related to the induction of non-fertile CE cysts. A total of fifty-eight individuals diagnosed with visceral hydatid cysts were selected, and they were further divided according to cyst fertility into fertile and non-fertile. Immunohistochemistry for CD4, CD8, and GrB was done. According to the results, hydatid cysts are common in adults and have no gender preference. The same clinical and laboratory data were shared by patients with fertile and non-fertile cysts (p = 0.186). GrB expression was not impacted by the fibrous deposition inside the hydatid cyst wall (p = 0.85); however, GrB was significantly correlated with the inflammatory density (p = 0.005). GrB expression was also found to be significantly higher in non-fertile cysts (p = 0.04). GrB expression is positively correlated with CD4 and CD8 expression. In conclusion, the expression of GrB in hydatid cysts may exacerbate the inflammatory response and impede cyst fertility while not affecting the fibrous deposition in the cyst wall.

Challenges and Prospective of Enhancing Hydatid Cyst Chemotherapy by Nanotechnology and the Future of Nanobiosensors for Diagnosis

Hydatid cysts have been widely recognized for decades as a common medical problem that affects millions of people. A revolution in medical treatment may be on the prospect of nanotechnology enhancing chemotherapy against hydatid cysts. An overview of nanotechnology's impact on chemotherapeutics is presented in the current review. It discusses some of the challenges as well as some of the opportunities. The application of nanotechnology to enhance chemotherapy against hydatid cysts is what this review will explore. Nanotechnology is a critical component of delivering therapeutic agents with greater precision and efficiency and targeting hydatid cysts with better efficacy, and minimizing interference with surrounding tissue. However, there are biodistribution challenges, toxicity, and resistance problems associated with nanotherapeutics. Additionally, nanobiosensors are being investigated to enable the early diagnosis of hydatid cysts. A nanobiosensor can detect hydatid cysts by catching them early, non-invasively, rapidly, and accurately. The sensitivity and specificity of diagnostic tests can be enhanced with nanobiosensors because they take advantage of the unique properties of nanomaterials. By providing more precise and customized treatment options for hydatid cysts, nanotechnology may improve therapeutic options and strategies for diagnosing the disease. In conclusion, treatment with nanotechnology to treat hydatid cysts is potentially effective but presents many obstacles. Furthermore, nanobiosensors are being integrated into diagnostic techniques, as well as helping to diagnose patients earlier and more accurately.

Hepatic macrophages play critical roles in the establishment and growth of hydatid cysts in the liver during Echinococcus granulosus sensu stricto infection

Cystic echinococcosis (CE) is a worldwide neglected zoonotic disease caused by infection with the larval stage of the tapeworm Echinococcus granulosus sensu lato (E. granulosus s.l.), which predominantly resides in the liver accompanied by mild inflammation. Macrophages constitute the main cellular component of the liver and play a central role in controlling the progression of inflammation and liver fibrosis. However, the role of hepatic macrophages in the establishment and growth of hydatid cysts in the liver during E. granulosus sensu stricto (E. granulosus s.s.) infection has not been fully elucidated. Here, we showed that CD68+ macrophages accumulated in pericystic areas of the liver and that the expression of CD163, a marker of anti-inflammatory macrophages, was more evident in active CE patients than in inactive CE patients. Moreover, in a mouse model of E. granulosus s.s. infection, the pool of hepatic macrophages expanded dramatically through the attraction of massive amounts of monocyte-derived macrophages (MoMFs) to the infection site. These infiltrating macrophages preferentially polarized toward an iNOS+ proinflammatory phenotype at the early stage and then toward a CD206+ anti-inflammatory phenotype at the late stage. Notably, the resident Kupffer cells (KCs) predominantly maintained an anti-inflammatory phenotype to favor persistent E. granulosus s.s. infection. In addition, depletion of hepatic macrophages promoted E. granulosus s.s. larval establishment and growth partially by inhibiting CD4+ T-cell recruitment and liver fibrosis. The above findings demonstrated that hepatic macrophages play a vital role in the progression of CE, contributing to a better understanding of the local inflammatory responses surrounding hydatid cysts and possibly facilitating the design of novel therapeutic approaches for CE.

Establishment of a secondary infection laboratory model of Echinococcus shiquicus metacestode using BALB/c mice and Mongolian jirds (Meriones unguiculatus)

Echinococcus shiquicus is peculiar to the Qinghai–Tibet plateau of China. Research on this parasite has mainly focused on epidemiological surveys and life cycle studies. So far, limited laboratory studies have been reported. Here, experimental infection of E. shiquicus metacestode in BALB/c mice and Mongolian jirds (Meriones unguiculatus) was carried out to establish alternative laboratory animal models. Intraperitoneal inoculation of metacestode material containing protoscoleces (PSCs) obtained from infected plateau pikas were conducted on BALB/c mice. Furthermore, metacestode material without PSCs deriving from infected BALB/c mice was intraperitoneally inoculated to Mongolian jirds. Experimental animals were dissected for macroscopic and histopathological examination. The growth of cysts in BALB/c mice was infiltrative, and they invaded the murine entire body. Most of the metacestode cysts were multicystic, but a few were unilocular. The cysts contained sterile vesicles, which had no PSCs. The metacestode materials were able to successfully infect new mice. In the jirds model, E. shiquicus cysts were typically formed freely in the peritoneal cavity; the majority of these cysts were free while a small portion adhered loosely to nearby organs. The proportion of fertile cysts was high, and contained many PSCs. The PSCs produced in Mongolian jirds also successfully infected new ones, which confirms that jirds can serve as an alternative experimental intermediate host. In conclusion, a laboratory animal infection was successfully established for E. shiquicus using BALB/c mice and Mongolian jirds. These results provide new models for the in-depth study of Echinococcus metacestode survival strategy, host interactions and immune escape mechanism.

Apoptosis as a Potential Target to Arrest and Survival of Hydatid Cyst

Background

Hydatidosis is a serious and life-threatening disease that may lead to the death of the host if diagnosed and treated improperly. Apoptosis has been investigated as a mechanism of host innate immunity in suppressing parasites and also the survival of cysts in the human body. The present study investigates the process and role of apoptosis caused by a host cell or parasite in hydatid cysts.

Materials and Methods

Survey cytotoxic effect and apoptotic mortality of hydatid-treated lymphocytes were investigated. Also, to determine the mechanism of apoptosis in host and parasite, the mean gene expressions of Bcl-2, Bax, Caspase 3 in hydatid-treated lymphocytes, and Fas-L gene in the laminated-germinal layer of fertile and infertile hydatid cysts were evaluated.

Results

The viability of fertile and infertile hydatid fluid-treated lymphocytes was significantly different compared with the control group. Flow cytometry also showed apoptotic cells. Bax mean gene expression was significantly different between fertile and infertile treated lymphocytes. However, there was no significant difference in the mean expression of Caspase 3, and Bcl-2 genes in these two groups. Although the expression of the Fas-L gene in infertile cysts was higher than in fertile cysts, the result was not significant.

Conclusion

It seems that hydatid cyst fluid may induce apoptosis in lymphocytes so that, hydatid cysts can escape from the immune system and stay alive. On the other hand, the results represent the possible immune path of host apoptosis against the parasite as one of the important routes in infertility of hydatid cysts.

Evaluation of the Local Immune Response to Hydatid Cysts in Sheep Liver

In order to characterize the inflammatory phenotype of livers of sheep naturally infected by cystic echinococcosis, 100 sheep livers have been macroscopically assessed for the presence of hydatid cysts and sampled for histopathological and molecular analysis. According to gross and microscopic examination, livers were subsequently classified into three groups: normal liver (Group A), liver with the presence of fertile hydatid cysts (Group B), and liver with the presence of sterile hydatid cysts (Group C). Immunohistochemical analyses were accomplished using primary antibodies anti-Iba1, anti-CD3, anti-CD20, anti-TGF-β, and anti-MMP9. Finally, real-time PCR was performed in order to estimate the concentration levels of tumor necrosis factor-α (TNF-α), interferon-γ (INF-γ), interleukin (IL)-12, IL-10, and TGF-β. Immunohistochemical analysis showed a diffuse immunolabelling of mononuclear cells for Iba-1 and TGF-β and a higher amount of CD20+ B cells compared to CD3+ T cells in both Groups B and C. The expression levels of Th-1-like immune cytokines TNF-α, INF-γ, and IL-12 did not show significant statistical differences. However, we found a significant increase in expression levels of Th-2 immune cytokines TGF-β and IL-10 in Groups B and C compared to Group A. Taken together, our findings suggest that macrophages have a predominant role in the local immune response to cystic echinococcosis. Moreover, we can speculate that Th2 immunity may be dominant, corroborating the idea that B cells are decisively essential in the control of the immune response during parasitic infection and that the immunomodulatory role of IL-10 and TGF-β may ensure the persistence of the parasite within the host.

Genetic diversity of Echinococcus granulosus sensu lato in China: Epidemiological studies and systematic review

Cystic echinococcosis (CE) is a neglected tropical zoonosis caused by Echinococcus granulosus sensu lato (s.l.) and remains a major public health concern globally. Here, CE isolates (n = 3310) with clearly defined genotypes and geographical origins in China were retrieved through our epidemiological survey (2016-2020) and systematic review (1992-2020). Existing known genotypes of Echinococcus granulosus sensu lato (E. granulosus s.l.) except for G4 have been found in China, particularly on the Tibetan Plateau, where their genetic diversity is unique to that part of the world. According to the systematic review, genetic compositions of E. granulosus s.l. in China were as follows: E. granulosus (G1, G3), 98.3%; Echinococcus ortleppi (G5), 0.1%; Echinococcus intermedius (G6, G7), 1.4%; and Echinococcus canadensis (G8, G10), 0.2%. Specifically, G1 was responsible for 97.7% of infections and characterized by the broadest host ranges and geographic distributions. Our epidemiological results showed a relatively stable genetic composition of E. granulosus s.l. in sheep and yaks from three CE hyperendemic provinces (Xinjiang, Sichuan, Qinghai). A higher proportion of fertile cysts were found in sheep (287/406, 70.7%) than in yaks (28/184, 15.2%). During the past 29 years, 51 cox1 haplotypes of E. granulosus s.l. were endemic in China. The ancestral haplotype (Hap_2) remained the most common haplotype, 12 relatively common haplotypes were endemic and nine newly reported haplotypes were found during the survey. Overall, our results demonstrate that the compulsory immunization of sheep and the pilot EG95 vaccination campaign in yaks are well matched with the current genotypic situation. In addition to yaks, we advocate for more surveillance of CE isolates from pigs, cattle, goats and camels, since their roles in the transmission and reservation of E. granulosus s.l. have been largely ignored in China.

In Vivo Therapeutic Effect of Some Medicinal Plants' Methanolic Extracts on the Growth and Development of Secondary Hydatid Cyst Infection

PURPOSE

The current study aimed to explore the in vivo therapeutic effects of the methanolic extracts of Citrullus colocynthis, Ruta graveolens, and Peganum harmala against hydatid cyst secondary infection.

METHODS

Aerial parts of P. harmala and R. graveolens, including leaves and stems, and seeds of C. colocynthis were collected and extracted using absolute methanol. Rats that are infected with secondary infection of hydatid cysts were treated orally and intraperitoneally according to the determined lethal doses for 30 days. Histological, hematological, and biochemical investigations were done 8 months after the infection.

RESULTS

Compared to Albendazole drug, C. colocynthis, and P. harmala, the methanol extract of R. graveolens showed higher and significant (P < 0.05) therapeutic effects on the secondary hydatid cysts growth. Those effects were represented by the reduction in the cysts' number, size, and weight; as well as the significant changes (P < 0.05) in values of hematological and biochemical parameters, the elevation of IFN-γ levels, and the decline of IL-10 and IL-4 cytokines, compared to the negative control group in both routes of treatment (oral and IP). Moreover, the histological sections showed that R. graveolens has a clear damaging effect on the hydatid cysts GL in the infected rats represented by the detachment of GL from LL and AL.

CONCLUSION

This study can open an avenue to find new therapeutics for secondary hydatid cyst infections using the studied plant extracts, especially the extract of R. graveolens.

Autoimmunity in human CE: Correlative with the fertility status of the CE cyst

Cystic echinococcosis is speculated to exert several immune-evasion strategies involving autoimmune-phenomena. We evaluated the hypothesizes that the prevalence of autoantibodies increases in the sera of CE patients that may evidence the association between the parasite and autoimmune diseases. Sera from 63 subjects at distinct types of CE cyst fertility were investigated for antinuclear antibodies (ANA), and anti-CCP antibodies. Plasma levels and cellular production of IL-17A cytokine were specifically defined as being assumed to prime for autoimmunity. Healthy-controls were age and gender-matched to test sera. ANA expressions inside the surgically removed metacestode and adventitial layer were also assayed. Out of 63 patients, 35 % had fertile highly viable cysts (group-1), 41 % had fertile low viable cysts (group-2) and 24 % had non-fertile cysts (group-3). A four-fold increase in ANA sera-levels was detected in group-1 compared with their controls (p-value 0.001) while anti-CCP levels were of insignificant differences. In group-2 and group-3, no significant differences were detected between ANA and anti-CCP sera-levels in CE patients and their controls. IL-17A sera-levels in group-1 and group- 2 were significantly higher than their healthy-controls while being of insignificant differences in group-3, p-value= 0.300. No association was detected between sera-levels of IL-17A and ANA as well as anti-CCP antibodies. Interestingly, relative IL-17A cellular expression associated positive ANA deposition in the parasite cells and adventitial layer. Collectively, based on the parasite fertility, IL-17A and ANA seemed to be involved in the host immune defenses against CE. There is no association between CE and anti-CCP antibodies.

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.

Occurrence and genetic characterization of Echinococcus granulosus sensu lato from domestic animals in Central Iran

Background

The species complex of Echinococcus granulosus sensu lato (s.l.) causes cystic echinococcosis distributed worldwide. There is no genotype information from hydatid cysts in the intermediate hosts in Central Iran. Therefore, in this study, we analyzed the hydatid cysts in livestock slaughtered in an abattoir in this region. Six hundred fifty-seven hydatid cysts were isolated from 97 animals, including sheep, cattle, camels, and goats slaughtered in Yazd abattoir from September 2018 to January 2020. The demographic data was collected as well as cyst location, fertility, and viability. Out of 657 samples, 164 samples were genotyped. Then, phylogenetic analysis was performed using MEGAX. Statistical analyses were done using SPSS version 16.0 by chi-square with a significant difference of less than 0.05.

Results

Out of 164 samples, the G1-G3 complex genotype had the most frequency in samples, with 135 cases recognized. The G6/G7 was observed in 19 isolates and G5 was reported in nine samples. One sample was detected as Taenia hydatigena.

Conclusions

This study showed that G1-G3 and G6/G7 genotypes were presented in all animals, but G5 was reported only in cattle, goats, and camels. It is the first molecular identification of cystic echinococcosis in Central Iran. Hence, reporting G5 in livestock in this area should be considered due to transmission to humans.

CD3/TCRE Expression and Immunoregulatory Milieu Induced in a Secondary Intermediate Host by Different Phases of Hydatid Cyst

BACKGROUND

Echinococcosis is a common health problem in the Mediterranean and the Middle East, and manifests without any symptoms, even in the advanced stages.

OBJECTIVE

The present study aimed to investigate the cell mediated-immunoregulatory milieu in rats' echinococcosis induced by three different viability status of Echinococcus granulosus especially in the semi-calcareous stage, which can be used as novel biomarkers to monitor disease progression and open the door to a deeper understanding of the pathways that could contribute to complementary echinococcosis therapies.

MATERIALS AND METHODS

Rat infection with echinococcosis was induced by three different viable statuses of Echinococcus granulosus (G6) camel strain. During the different stages of parasitic infection, blood serum was harvested from rats containing low-, high-, and not viable (not completely transformed to the calcareous status) protoscoleces fluid. The host Th1/Th2 cytokines-mediated immune cell activation, as well as CD3/TCRE immunoregulation, and proliferation responses were investigated; especially in the semi-calcareous stage as this is the first report characterizing this stage.

RESULTS

Both IFN-γ and IL-6 levels significantly increased in the infected groups (P < 0.05), in addition, increased positive immunoreactions in splenic tissue for both CD3/TCRE and Ki-67 monoclonal antibodies.

CONCLUSION

E. granuloses infection-induced immune tolerance is involved in disease progression, and modulates the activation and regulation of host immune response, even in the early stages of infection, rather than the last stages of viability (semi-calcareous) is not neglected stage. This study is the first to report that the semi-calcareous stage causes a severe immunological response.

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.

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.

Th1/Th2/Th17 cytokine profile in hepatic cystic Echinococcosis patients with different cyst stages

AIMS

The study aimed to investigate possible correlation between expression level of Th1/Th2/Th17-type profile and cyst viability in the systemic and local immunity of hepatic cystic Echinococcosis (CE) patients.

METHODS AND RESULTS

Expression of Th1-type interleukin (IL)-2, interferon (IFN)-γ, tumour necrosis factor (TNF)-α, Th2-type IL-4, IL-6, IL-10 and Th17-type IL-17A was examined in the serum and liver samples of hepatic CE patients with different cyst stages. Compared with healthy controls, Th1/Th2/Th17-type cytokines were significantly increased in the serum of hepatic CE patients. Moreover, expression of these cytokines was also at higher level in the inflammatory cell band of peri-lesion liver (PL) tissues than that in the adjacent normal (AN) liver tissues. Interestingly, elevation of Th1-type and Th17-type cytokines was more evident in PL tissues of patients with inactive cysts. Relatively, Th2-type cytokines were predominant in PL tissues of patients with active cysts.

CONCLUSION

Our findings provide new insights that Th1/Th2/Th2-type cytokine profile was associated with cyst stages. In hepatic CE patients with inactive cysts, Th1 and Th17-type cytokines were predominant. Comparatively, Th2-type cytokines were more evident in hepatic CE patients with active cysts, which may provide basis for the immune response diversity in hepatic CE patients with different cyst stages.

Fasciola hepatica co-infection enhances Th1 immune response in the adventitial layer of non-fertile Echinococcus granulosus cysts

Cystic echinococcosis is a widespread zoonosis caused by the larval stage of the tapeworm Echinococcus granulosus. In intermediary hosts, two types of echinococcal cysts can be found: fertile, which produce protoscoleces, the infective form of the parasite to dogs; and infertile, that do not present protoscoleces and therefore are not able to continue with the parasite life cycle. The adventitial layer, the local immune response against the cyst, plays an important role in cyst fertility. Grazing cattle can often feature Fasciola hepatica co-infection, a parasite known to modulate the host systemic immune response. In this work the cellular Th1/Th2 immune profiles were evaluated in the adventitial layer of fertile and non-fertile cysts with and without co-infection with Fasciola hepatica. Measuring with immunohistochemistry and qPCR in adventitial layer, we report that non-fertile cysts present higher levels of Th1 cytokines (IFN-γ (P < 0.0001) and TNF-α (P < 0.05)), and fertile cysts have higher levels of Th2 cytokines (IL-4 (P < 0.001)). Co-infection with Fasciola hepatica is associated with a decrease in the expression of IL-4 (P < 0.05) and an increase in the expression of IFN-γ (P < 0.0001) in the adventitial layer of fertile cysts. Non-fertile cysts were associated with higher levels of Th1 cytokines in the adventitial layer, with IFN-γ expression enhanced by F. hepatica co-infection (P < 0.0001), confirming that polyparasitism should be considered in the treatment and control of naturally infected cattle.

Cattle co-infection of Echinococcus granulosus and Fasciola hepatica results in a different systemic cytokine profile than single parasite infection

E. granulosus is a cestode that causes Cystic Echinococcosis (CE), a zoonotic disease with worldwide presence. The immune response generated by the host against the metacestode induces a permissive Th2 response, as opposed to pro-inflammatory Th1 response. In this view, mixed Th2 and regulatory responses allow parasite survival. Overall, larval Echinococcus infections induce strong regulatory responses. Fasciola hepatica, another common helminth parasite, represents a major infection in cattle. Co-infection with different parasite species in the same host, polyparasitism, is a common occurrence involving E. granulosus and F. hepatica in cattle. ‘While it is known that infection with F. hepatica also triggers a polarized Th2/Treg immune response, little is reported regarding effects on the systemic immune response of this example of polyparasitism. F. hepatica also triggers immune responses polarized to the Th2/ Treg spectrum. Serum samples from 107 animals were analyzed, and were divided according to their infection status and Echinococcal cysts fertility. Cytokines were measured utilizing a Milliplex Magnetic Bead Panel to detect IFN-γ, IL-1, IL-2, IL-4, IL-6, IL-10, IL-12 and IL-18. Cattle infected only with F. hepatica had the highest concentration of every cytokine analyzed, with both 4.24 and 3.34-fold increases in IL-10 and IL-4, respectively, compared to control animals, followed by E. granulosus and F. hepatica co-infected animals with two-fold increase in IL-10 and IL-4, compared to control animals, suggesting that E. granulosus co-infection dampens the cattle Th2/Treg immune response against F. hepatica. When considering Echinococcal cyst fertility and systemic cytokine concentrations, fertile cysts had higher IFN-γ, IL-6 and IL-18 concentrations, while infertile cysts had higher IL-10 concentrations. These results show that E. granulosus co-infection lowers Th1 and Th2 cytokine serological concentration when compared to F. hepatica infection alone. E. granulosus infections show no difference in IFN-γ, IL-1, IL-2, IL-6 and IL-18 levels compared with control animals, highlighting the immune evasion mechanisms of this cestode.

Fasciola hepatica coinfection modifies the morphological and immunological features of Echinococcus granulosus cysts in cattle

Polyparasitism occurs when animals harbour multiple parasites concomitantly. It is a common occurrence but is generally understudied in wild and domestic animals. Fasciola hepatica and Echinococcus granulosus, which are helminths of ungulates, frequently coinfect cattle. The effects of this particular type of polyparasitism are not well documented. The metacestode of Echinococcus granulosus is surrounded by the adventitial layer, which constitutes the host immune response to the parasite. This layer in cattle is produced by a granulomatous reaction and is involved in echinococcal cyst (EC) fertility. Due to the systemic immune-modulating abilities of Fasciola hepatica, coinfection possibly generates a favourable environment for EC growth. A total of 203 Echinococcus granulosus sensu stricto cysts were found in 82 cattle, of which 42 ECs were found in 31 animals coinfected with Fasciola hepatica. The overall infection intensity was 3 cysts per animal. Coinfection with Fasciola hepatica decreased the mean infection intensity to 1.4 cysts per animal. Regarding EC size, coinfection resulted in smaller ECs (15.91 vs 22.09 mm), especially for infertile lung cysts. The adventitial layer of ECs in coinfected animals lacked lymphoid follicles and palisading macrophages, which are generally hallmarks of the granulomatous immune response. The ECs in coinfected animals had organized laminated layers, whereas those in animals without coinfection did not. Although coinfection was not statistically associated with EC fertility, we did not find fertile cysts in the livers of coinfected animals. We concluded that coinfection with Fasciola hepatica and Echinococcus granulosus has a detrimental effect on ECs, particularly infertile cysts.

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.

Multiple haplotypes of Echinococcus granulosus sensu stricto in single naturally infected intermediate hosts

Cystic echinococcosis is a disease that affects both humans and animals, caused by cryptic species complex belonging to the platyhelminth Echinococcus granulosus sensu lato (s.l.). This disease is distributed worldwide, with E. granulosus sensu stricto (s.s.) being the most widespread of the species. High genetic variability has been demonstrated within E. granulosus s.s. studying single cyst per infected animal identifying a number of different haplotypes. However, few studies have addressed the genetic diversity of this parasite within a single intermediate host with multiple Echinococcus cysts. To date, it remains unknown if specific haplotypes of E. granulosus s.s. produce differences in biological features of the cyst. Here, we use the full length of the mitochondrial gene cox1 to determine E. granulosus s.s. haplotypes in samples from both cattle and sheep which harboured more than one cyst in different areas in Chile, where this parasite is endemic. We found 16 different haplotypes in 66 echinococcal cysts from 10 animals, and both cattle and sheep can harbour up to five different haplotypes of E. granulosus s.s. in the same animal. Regarding cyst fertility, five animals had both fertile and infertile Echinococcus cysts in both single and multiple haplotype infections. There was no association between haplotype and cyst fertility, size, or adventitial layer characteristics. Sampling and sequencing every Echinococcus cyst found in the intermediate host reveals a high molecular variability. We speculate that multiple haplotype infections could also suggest that intermediate hosts come from hyperendemic areas.

Lymphocyte Populations in the Adventitial Layer of Hydatid Cysts in Cattle: Relationship With Cyst Fertility Status and Fasciola Hepatica Co-Infection

Cystic echinococcosis is a worldwide zoonosis caused by the cestode Echinococcus granulosus. Two types of hydatid cysts occur in intermediate hosts: fertile cysts that generate protoscoleces from the germinal layer of the cyst, and infertile cysts that do not produce protoscoleces and are unable to continue the life cycle of the parasite. The adventitial layer, a host-derived fibrous capsule surrounding the hydatid cyst, is suggested to play an important role in local immune regulation during infection and in fertility of the cysts. Fasciola hepatica, another important parasite of cattle, induces a characteristic Th2-like immune response that could modulate the immune response against E. granulosus. Natural co-infection of both parasites is common in cattle, but no reports describe the local immune response against E. granulosus with F. hepatica infection in the same host. This study analyzed the number and distribution of T and B cells in the adventitial layer of liver and lung cysts and the relationship with cyst fertility and F. hepatica co-infection. T lymphocytes were the predominant cell type in the adventitial layer of infertile hydatid cysts and were more numerous in infertile hydatid cysts. B lymphocyte numbers were not associated with hydatid cyst fertility. Mast cells were infrequent in the adventitial layer. The number of T and B cells was not associated with F. hepatica co-infection. The present study contributes to the understanding of local immune responses in bovine cystic echinococcosis.