Echinococcus granulosus: The establishment of the metacestode in the liver is associated with control of the CD4+ T-cell-mediated immune response in patients with cystic echinococcosis and a mouse model

Histologic, histochemical, and immunohistochemical changes in buffalo liver with cystic echinococcosis

The present study aimed to evaluate the histologic, histochemical, and immunohistochemical changes in buffalo livers with cystic echinococcosis. Noninfected and infected livers were collected from the freshly slaughtered buffalo at the Aligarh abattoir. Small pieces of both infected and noninfected livers (n = 5) were cut and processed for histologic and histochemical studies. Immunohistochemistry was performed using rabbit anti-CD3, CD19, and CD117 antibodies. The results revealed the presence of brood capsules and germinal and laminated membranes surrounded by a fibrous adventitial layer, followed by moderate and diffused infiltration of eosinophils, monocytes, neutrophils, lymphocytes, and marked focal infiltration of mast cells. The infected livers also had mild dilation of central veins and sinusoids, mild and focal necrosis of hepatic tissue, and congestion of central and portal veins. Periodic acid-Schiff reaction revealed marked glycogen depletion in the infected liver. Masson's trichrome stain showed marked deposition of collagen fibers in the portal area, adventitial layer, and between the hepatocytes compared with the noninfected liver, where deposition was found only in the portal area. The T-cell response was more pronounced than the B-cell response in infected liver. Thus, it can be concluded that hydatid cyst infection causes several pathological and biochemical changes and increased infiltration of inflammatory cells in the infected livers, suggesting the involvement of nonspecific immune responses against hydatid cysts. The T-cell response was more pronounced than B-cells, indicating the involvement of cell-mediated immunity against cystic echinococcosis. These findings may help to understand the local immune responses to cystic echinococcosis.

GHSR gene knockout alleviates the liver pathological response in Echinococcus granulosus infection by reducing parasite survival

Cystic echinococcosis (CE) is a parasitic disease caused by the larval stage of Echinococcus granulosus, and the immunosuppressive microenvironment exacerbates disease progression. Ghrelin, a peptide hormone, plays a role in modulating immune inflammation and may influence the progression of E. granulosus infection through its receptor, GHSR (growth hormone secretagogue receptor). However, whether GHSR downregulation can inhibit E. granulosus infection remains unclear. In this study, we extracted liver tissues from E. granulosus-infected mice and those treated with the GHSR antagonist [D-Lys3]-GHRP-6. Proteomic analysis revealed 341 differentially expressed proteins, of which 185 were upregulated and 156 were downregulated. Metabolomic sequencing revealed 101 differentially expressed metabolites, including 62 upregulated and 39 downregulated metabolites. KEGG pathway enrichment analysis of both proteomic and metabolomic data revealed seven key signalling pathways, 11 key proteins, and 26 key metabolites that interact through metabolic and organic system networks. Next, we examined the disease progression of E. granulosus infection in GHSR-knockout mice. Compared with the E. granulosus (Eg) group, the GHSR-KO group presented a significant reduction in the number of liver infection foci. The serum and liver ghrelin levels were significantly greater in the E. granulosus group than in the control group, along with increased secretion of proinflammatory cytokines (IL-2 and IFN-γ) and decreased secretion of anti-inflammatory cytokines (IL-4 and IL-10). In contrast, the GHSR-KO group presented significantly lower ghrelin levels in both the serum and liver, with reduced proinflammatory cytokine secretion and increased anti-inflammatory cytokine secretion, similar to those of the control group. Furthermore, ghrelin and inflammation-related factors, including MyD88, NF-κB p65, iNOS, and Arg-1, exhibited coordinated expression changes in liver lesions and surrounding areas. These findings suggest that GHSR gene knockout can ameliorate the progression of liver E. granulosus infection and associated liver inflammation.

Investigating the Therapeutic Effects of Albendazole, Mebendazole, and Praziquantel Nanocapsules in Hydatid Cyst-Infected Mice

Drug resistance is the main challenge in treating parasitic diseases, including cystic echinococcosis (CE). Hence, the current study aims to investigate the effect of nanocapsules containing albendazole (ABZ), mebendazole (MBZ), and praziquantel (PZQ) on treating hydatid cysts in mice using these high-potency drugs. A total of 78 female white laboratory mice (BALB/C mice), 8 weeks old and weighing 25 g, were intraperitoneally injected with 1500 live protoscoleces of Echinococcus granulosus. The first group received ABZ nanocapsules, group 2 received MBZ nanocapsules, group 3 received PZQ nanocapsules, group 4 received ABZ + MBZ nanocapsules, group 5 received ABZ + PZQ nanocapsules, and group 6 received MBZ + PZQ nanocapsules. Each group also had a control group, which received the non-nanocapsulated drugs (group 7-12). Group 13 received no treatment and served as the negative control, just receiving phosphate-buffered saline (PBS). A thorough examination of the cysts' physical properties, including size, quantity, and weight, was carried out. According to our results, the polymeric nanocapsules are sphere-like and of different sizes. The total number of cysts in all nanocapsule groups significantly decreased compared to the control group. In the total weight of the cysts, ABZ + MBZ nanocapsules, ABZ + PZQ nanocapsules, and MBZ + PZQ nanocapsules had the least total cyst weight, showing that the use of the medicinal combination had a better effect on the penetration and weight reduction of the cysts. In conclusion, the findings showed that ABZ, MBZ, and PZQ significantly reduced the size, weight, and number of hydatid cysts in the mouse model used in this study.

Inhibition of the MyD88 signaling pathway could upregulates Ghrelin expression to synergistically regulate hepatic Echinococcus multilocularis-infected progression

Introduction

AE and whether the inhibition of the MyD88 inflammatory pathway can enhance Ghrelin expression to collaboratively modulate AE progression remains unclear.

Methods

In this study, we evaluated Ghrelin serum levels and changes in TLR4/MyD88/NF-κB pathway proteins and inflammatory factors in AE patients and E. multilocularis mouse models at different stages of infection (-4, -8, and -12 weeks). Additionally, we administered the MyD88 inhibitor TJ-M2010-5 intraperitoneally to infected mice to evaluate alterations in inflammation and Ghrelin levels, as well as disease progression.

Results

A decrease in serum Ghrelin levels in AE patients, whereas both Ghrelin and GHSR, along with TLR4/MyD88/NF-κB pathway proteins and markers of M1/M2 macrophage polarization, exhibited increased expression in the inflammatory cell zones surrounding hepatic lesions. Similar findings were observed in E. multilocularis-infected mice. M1-type inflammatory expression predominated throughout the infection's progression, with sustained high levels of Ghrelin counteracting inflammation. The TLR4/ MyD88/NF-κB pathway remained suppressed during the first 8 weeks, becoming activated only at 12 weeks. Inhibition of the MyD88 pathway resulted in reduced inflammation levels and upregulated Ghrelin expression, thereby collaboratively regulating the progression of hepatic infection.

Conclusion

These findings suggest an interactive regulation between the MyD88 inflammatory signaling pathway and Ghrelin, indicating that MyD88 inhibition could enhance Ghrelin expression to modulate the progression of E. multilocularis infection.

Mannan-Decorated Lipid Calcium Phosphate Nanoparticle Vaccine Increased the Antitumor Immune Response by Modulating the Tumor Microenvironment

With the rapid development of tumor immunotherapy, nanoparticle vaccines have attracted much attention as potential therapeutic strategies. A systematic review and analysis must be carried out to investigate the effect of mannose modification on the immune response to nanoparticles in regulating the tumor microenvironment, as well as to explore its potential clinical application in tumor therapy. Despite the potential advantages of nanoparticle vaccines in immunotherapy, achieving an effective immune response in the tumor microenvironment remains a challenge. Tumor immune escape and the overexpression of immunosuppressive factors limit its clinical application. Therefore, our review explored how to intervene in the immunosuppressive mechanism in the tumor microenvironment through the use of mannan-decorated lipid calcium phosphate nanoparticle vaccines to improve the efficacy of immunotherapy in patients with tumors and to provide new ideas and strategies for the field of tumor therapy.

Association of IL-9 Cytokines with Hepatic Injury in Echinococcus granulosus Infection

Cystic echinococcosis (CE) is a zoonotic disease caused by the parasite Echinococcus granulosus (E. granulosus), which can lead to the formation of liver lesions. Research indicates that E. granulosus releases both Toll-like receptor 2 (TLR2) and Interleukin-9 (IL-9), which can potentially impair the body's innate immune defenses and compromise the liver's ability to fight against diseases. To investigate the role of TLR2 and IL-9 in liver damage caused by E. granulosus infection, samples were initially collected from individuals diagnosed with CE. Subsequently, BALB/c mice were infected with E. granulosus at multiple time points (4 weeks, 12 weeks, 32 weeks) and the expression levels of these markers was then assessed at each of these phases. Furthermore, a BALB/c mouse model was generated and administered anti-IL-9 antibody via intraperitoneal injection. The subsequent analysis focused on the TLR2/MyD88/NF-κB signaling pathway and the expression of IL-9 in E. granulosus was examined. A co-culture experiment was conducted using mouse mononuclear macrophage cells (RAW264.7) and hepatic stellate cells (HSCs) in the presence of E. granulosus Protein (EgP). The findings indicated elevated levels of IL-9 and TLR2 in patients with CE, with the activation of the signaling pathway significantly increased as the duration of infection progressed. Administration of anti-IL-9 in mice reduced the activation of the TLR2/MyD88/NF-κB signaling pathway, exacerbating liver injury. Moreover, EgP stimulates the TLR2/MyD88/NF-κB signaling pathway, resulting in the synthesis of α-SMA and Collagen I. The data suggest that infection with E. granulosus may stimulate the production of IL-9 through the activation of the TLR2/MyD88/NF-κB signaling pathway, which is mediated by TLR2. This activation stimulates RAW264.7 and HSCs, exacerbating liver injury and fibrosis.

Optimizing sheep B-cell epitopes in Echinococcus granulosus recombinant antigen P29 for vaccine development

Background

Echinococcus granulosus is a widespread zoonotic parasitic disease, significantly impacting human health and livestock development; however, no vaccine is currently available for humans. Our preliminary studies indicate that recombinant antigen P29 (rEg.P29) is a promising candidate for vaccine.

Methods

Sheep were immunized with rEg.P29, and venous blood was collected at various time points. Serum was isolated, and the presence of specific antibodies was detected using ELISA. We designed and synthesized a total of 45 B cell monopeptides covering rEg.P29 using the overlap method. ELISA was employed to assess the serum antibodies of the immunized sheep for recognition of these overlapping peptides, leading to the preliminary identification of B cell epitopes. Utilizing these identified epitopes, new single peptides were designed, synthesized, and used to optimize and confirm B-cell epitopes.

Results

rEg.P29 effectively induces a sustained antibody response in sheep, particularly characterized by high and stable levels of IgG. Eight B-cell epitopes of were identified, which were mainly distributed in three regions of rEg.P29. Finally, three B cell epitopes were identified and optimized: rEg.P2971-90, rEg.P29151-175, and rEg.P29211-235. These optimized epitopes were well recognized by antibodies in sheep and mice, and the efficacy of these three epitopes significantly increased when they were linked in tandem.

Conclusion

Three B-cell epitopes were identified and optimized, and the efficacy of these epitopes was significantly enhanced by tandem connection, which indicated the feasibility of tandem peptide vaccine research. This laid a solid foundation for the development of epitope peptide vaccine for Echinococcus granulosus.

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.

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.

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.

Upregulation of LAG3 modulates the immune imbalance of CD4+ T-cell subsets and exacerbates disease progression in patients with alveolar echinococcosis and a mouse model

Infection with the cestode Echinococcus multilocularis (E. multilocularis) causes alveolar echinococcosis (AE), a tumor-like disease predominantly affecting the liver but able to spread to any organ. T cells develop functional defects during chronic E. multilocularis infection, mostly due to upregulation of inhibitory receptors such as T-cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domains (TIGIT) and programmed death-1 (PD-1). However, the role of lymphocyte activation gene-3 (LAG3), an inhibitory receptor, in AE infection remains to be determined. Here, we discovered that high expression of LAG3 was mainly found in CD4+ T cells and induced regulatory T cells (iTregs) in close liver tissue (CLT) from AE patients. In a mouse model of E. multilocularis infection, LAG3 expression was predominantly found in T helper 2 (Th2) and Treg subsets, which secreted significantly more IL-4 and IL-10, resulting in host immune tolerance and disease progression at a late stage. Furthermore, LAG3 deficiency was found to drive the development of effector memory CD4+ T cells and enhance the type 1 CD4+ T-cell immune response, thus inhibiting metacestode growth in vivo. In addition, CD4+ T cells from LAG3-deficient mice produced more IFN-γ and less IL-4 when stimulated by E. multilocularis protoscoleces (EmP) antigen in vitro. Finally, adoptive transfer experiments showed that LAG3-knockout (KO) CD4+ T cells were more likely to develop into Th1 cells and less likely to develop into Tregs in recipient mice. Our work reveals that high expression of LAG3 accelerates AE disease progression by modulating the immune imbalance of CD4+ T-cell subsets. These findings may provide a novel immunotherapeutic strategy against E. multilocularis infection.