Role of Cytokines and Reactive Oxygen Species in the Amebic Liver Abscess Produced by Entamoeba histolytica

Pacheco‐Yépez, Judith; Martínez-Castillo, Moisés; Cruz, Cruz; Serrano-Luna, Jesús; Shibayama, Mineko

doi:10.1016/b978-0-12-804274-8.00014-x

Cited by 4 publications

(4 citation statements)

References 82 publications

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“…Amoebae also proliferate in specific areas, thereby forming apparent "nests". This behavior is similar to what is found in liver abscesses formed by E. histolytica [24]. In deeper periodontal lesions, we frequently found such formations of parasite nests, accompanied by a relative decrease in motile bacteria.…”

Section: Amoeba Interactions With Human and Microbial Cellssupporting

confidence: 89%

“…Strict topical and systemic pharmaceutical elimination of parasites accompanied by good hygiene habits generally lead to a cessation of bleeding, the elimination of pus and gingival healing, with a 95% pocket depth closure [31]. Clinical improvement is associated with the disappearance of inflammatory cells and reappearance of normal Green complex flora [24,36].…”

Section: Discussionmentioning

confidence: 99%

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Microscopy Analyses Reveal the Parasitism of Entamoeba gingivalis in Periodontitis: An Observational Study

Bonner¹

2022

JDOMS

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Background: Whereas the periodontal microbiota is well described, its non-bacterial component needs a better understanding. Metagenomic analyses show a strong increase of the protozoan Entamoeba gingivalis in inflamed periodontal pockets. Its presence is associated with periodontal deterioration and pockets typically 3mm or more in depth. The aim of this study is to observe the amoeba within the biofilm during active disease. Materials and Methods: Here, we present results of a phase contrast microscopy-based observation of amoebae in periodontal patients’ subgingival plaque from infected sulcus. Plaque samples from deepest part of sulcus are picked up and spread out between blade and coverslip in patient saliva medium. We relate significant behavior of the parasite during active periodontal disease. Results: From low power observation, parasite is quite frequent. Once targeted, high power observation confirms amoeban anatomy and presence. We observed a high degree of amoeba locomotion and movements toward specific environments within the subgingival plaque. This was accompanied by the formation of “channels” within the biofilm. We also present evidence of adhesion to human cells as well as characteristically parasitic behavior. Specifically, we observed the intrusion of amoeba pseudopods into leukocytes coupled with a decrease in leukocyte intracellular granular activity. We documented both single trogocytic processes and trogocytosis through multiple pseudopods. In addition to leukocytes, we also observed trogocytosis of red blood cells. Parasitic behavior was also evident from the observation of amoebae digesting the nuclei of multiple vacuolar white blood cells, simultaneously. Following trogocytosis, polynuclear neutrophils had the appearance of ghost cells. Finally, we show evidence for amoeba nesting and reproduction within periodontal pockets. Conclusion: Phase contrast microscopy of periodontal biofilms strongly suggests that E. gingivalis escapes the first lines of innate defenses and promotes a pathological state. Trogocytosis and exonucleophagy processes targeting neutrophils could consequently disrupt neutrophil extracellular traps activity and normal apoptotic function, a vital component of wound healing. This study points to Entamoeba gingivalis as a microbe involved in the inflammatory process during periodontitis and as a driver of the disease rather than a harmless commensal species.

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Section: Amoeba Interactions With Human and Microbial Cellssupporting

confidence: 89%

Section: Discussionmentioning

confidence: 99%

Microscopy Analyses Reveal the Parasitism of Entamoeba gingivalis in Periodontitis: An Observational Study

Bonner¹

2022

JDOMS

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“…The liver lymphocyte population consists of T and B cells, natural killer T (NKT) cells, NK cells and dendritic cells 29 . E histolytica induces the secretion of inflammatory IL‐1, IL‐6, TNF‐αγβ, INF‐γ, IL‐1β, IL‐8 and IL‐10 cytokines and TGF‐β1 30 . Polysaccharide mediates T‐cell activation and production of cytokines such as IL‐2, IL‐10 and interferon γ 31 .…”

Section: Discussionmentioning

confidence: 99%

Glycan moieties in Entamoeba histolytica ubiquitin are immunodominant

Flores

Obregón

Rangel

et al. 2020

Parasite Immunology

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The ubiquitin‐proteasome system plays a central role performing several functions to maintain parasite homeostasis. We have reported the partial characterization of N‐linked glycosylation profile in E. histolytica ubiquitin (EhUb). Here we examined the immunogenicity and antigenicity of carbohydrates in EhUbiquitin. Rabbits were immunized with purified EhUbiquitin or purified recombinant rUb expressed by E. coli. Using Western Blot, we explored the immunogenicity and antigenicity of protein portion and carbohydrates moiety. Interestingly, immunized rabbits produced antibodies to both Ub glycoprotein and rUb; but antibodies against carbohydrates were immunodominant, rather than antibodies to the protein moiety of EhUbiquitin. In addition, we observed that antibodies to protein moiety are not conserved in serum unless antigen is continually administrated. Conversely, anti‐Ub glycoprotein antibodies are well maintained in circulation. In humans, infection with Entamoeba histolytica induces strong IgG anti‐Ub response. The human antibodies recognize both, the protein moieties and the glycosylated structure. Entamoeba histolytica ubiquitin is immunogenic and antigenic. The glycan moieties are immunodominant and induces IgG. These data open the door to use carbohydrates as potential targets for diagnose tests, drugs and vaccine to prevent this parasitic disease.

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“…Amoebiasis is an infection of the gastrointestinal tract caused by the protozoan parasite Entamoeba histolytica ( E. histolytica ), which can invade the large intestine and produce acute intestinal diseases, such as amoebic colitis, or more severe clinical conditions, such as amoebic dysentery. Additionally, it can spread in a hematogenous manner to other organs, such as the lungs, brain, and liver, where extraintestinal necrotic lesions, such as an amoebic liver abscess (ALA) [ 1 ], give rise to high rates of morbidity and mortality worldwide [ 2 ].…”

Section: Introductionmentioning

confidence: 99%

Riluzole, a Derivative of Benzothiazole as a Potential Anti-Amoebic Agent against Entamoeba histolytica

et al. 2023

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Amoebiasis is produced by the parasite Entamoeba histolytica; this disease affects millions of people throughout the world who may suffer from amoebic colitis or amoebic liver abscess. Metronidazole is used to treat this protozoan, but it causes important adverse effects that limit its use. Studies have shown that riluzole has demonstrated activity against some parasites. Thus, the present study aimed, for the first time, to demonstrate the in vitro and in silico anti-amoebic activity of riluzole. In vitro, the results of Entamoeba histolytica trophozoites treated with IC50 (319.5 μM) of riluzole for 5 h showed (i) a decrease of 48.1% in amoeba viability, (ii) ultrastructural changes such as a loss of plasma membrane continuity and alterations in the nuclei followed by lysis, (iii) apoptosis-like cell death, (iv) the triggering of the production of reactive oxygen species and nitric oxide, and (v) the downregulation of amoebic antioxidant enzyme gene expression. Interestingly, docking studies have indicated that riluzole presented a higher affinity than metronidazole for the antioxidant enzymes thioredoxin, thioredoxin reductase, rubrerythrin, and peroxiredoxin of Entamoeba histolytica, which are considered as possible candidates of molecular targets. Our results suggest that riluzole could be an alternative treatment against Entamoeba histolytica. Future studies should be conducted to analyze the in vivo riluzole anti-amoebic effect on the resolution of amebic liver abscess in a susceptible model, as this will contribute to developing new therapeutic agents with anti-amoebic activity.

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Role of Cytokines and Reactive Oxygen Species in the Amebic Liver Abscess Produced by Entamoeba histolytica

Cited by 4 publications

References 82 publications

Microscopy Analyses Reveal the Parasitism of Entamoeba gingivalis in Periodontitis: An Observational Study

Microscopy Analyses Reveal the Parasitism of Entamoeba gingivalis in Periodontitis: An Observational Study

Glycan moieties in Entamoeba histolytica ubiquitin are immunodominant

Riluzole, a Derivative of Benzothiazole as a Potential Anti-Amoebic Agent against Entamoeba histolytica

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