Characterization of N-glycosylations in Entamoeba histolytica ubiquitin

Obregón, Adriana; Flores, M.; Rangel, Roberto; Arévalo, Katiuska; Maldonado, Gabriela Inés; Quintero, Isela; Galán, Luis de la Fuente

doi:10.1016/j.exppara.2018.11.003

Cited by 6 publications

(13 citation statements)

References 74 publications

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“…Then, interactions with galectins could induce an inflammatory response. Structures we have proposed have galactose or mannose as terminal residues 8 . It may be feasible that some mannose or galactose recognition systems regulate the biological function of ubiquitin.…”

Section: Discussionmentioning

confidence: 99%

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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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Section: Discussionmentioning

confidence: 99%

“…The most abundant glycans are Hex 5 GlcNAc 2 , Hex 3 GlcNAc 2 and Hex 4 GlcNAc 2 . We proposed a set of possible high mannose N‐ glycan structures that may represent good targets for anti‐amoebic drugs 8 …”

Section: Introductionmentioning

confidence: 99%

Glycan moieties in Entamoeba histolytica ubiquitin are immunodominant

Flores

Obregón

Rangel

et al. 2020

Parasite Immunology

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“…Although the absence of the Golgi apparatus in Entamoeba spp. has been commonly accepted (Sokolova, Snigirevskaia, & Komissarchik, 2007), homologous genes related to its functions have been reported (Dacks et al, 2003), and studied in E. histolytica (Bredeston et al, 2005; Carpentieri et al, 2010; García‐Rivera et al, 1999; Obregón et al, 2019). Glycosylation of integral membrane proteins participating in phagocytosis and immune response evasion suggest the presence of a functional Golgi apparatus (Bredeston et al, 2005; Perdomo et al, 2016; Petri Jr., Harque, & Mann, 2002).…”

Section: Introductionmentioning

confidence: 99%

Golgi apparatus components in Entamoeba histolytica and Entamoeba dispar after monensin treatment

Talamás‐Lara

Acosta-Virgen

Chávez‐Munguía

et al. 2021

Microscopy Res & Technique

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Highly dynamic ribosomes, glycogen granules, thinly fibrillar material, and multiple membrane-bound vesicles are embedded in the matrix-rich cytoplasm of Entamoeba spp. trophozoites. The absence of a Golgi apparatus in these amoebae has been commonly accepted. Here we challenge this observation by incubating Entamoeba histolytica and Entamoeba dispar with monensin, an ionophore that produces swelling of the Golgi apparatus. We observe changes in the trophozoites through standard transmission electron microscopy, cryofixation and cryosubstitution, and analyze the label and expression of known resident proteins of the cis-GM130 and trans-TGN38 Golgi network through confocal microscopy and Western blot assays. Cryosubstitution and standard methods using the treatment, preserved membranous lamellae resembling Golgi components. GM130 and TGN38 Golgi antigens were found by immunoelectron, immunoblot, and co-localization by confocal microscopy using the reagent NBD C6-ceramide. Our results indicate that previously undetected Golgi apparatus components are present in the cytoplasm of E. histolytica and E. dispar.

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“…6,7 In a previous study, we found high mannose N-glycan structures on the ubiquitin of E. histolytica; Hex5GlcNAc2, Hex3GlcNAc2 and Hex4GlcNAc2 are the most abundant glycans. 8 After that, we determined the role of carbohydrates in the immunogenicity and antigenicity of E. histolytica Eh ubiquitin and their ability to induce antibodies in rabbits. We showed that the glycan moieties are immunodominant and induce antibodies, immunizing animals with purified Ehub or purified recombinant E. histolytica recombinant ubiquitin (rEhub) expressed by E. coli.…”

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confidence: 99%

“…We showed that the glycan moieties are immunodominant and induce antibodies, immunizing animals with purified Ehub or purified recombinant E. histolytica recombinant ubiquitin (rEhub) expressed by E. coli. 8,9 Inhabitants of areas endemic to E. hystolytica have high seroprevalence of antibodies to amoebas, even if they have not suffered invasive amoebiasis. Antibodies from animals with experimental amoebic liver abscess recognize the membrane proteins of E. histolytica trophozoites.…”

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confidence: 99%

Ubiquitin of Entamoeba histolytica induces antibody response in patients with invasive amoebiasis

Flores

Tamez

Rangel

et al. 2022

Parasite Immunology

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Entamoeba histolytica causes amoebic liver abscess (ALA) in humans. The injury of target cells by E. histolytica includes processes controlled by the ubiquitin Ehub. Previously, we found immunodominance of Ehub glycan moieties using immunized rabbits. In this work, we analysed dominance of antibodies to the glycoprotein Ehub in the sera from 52 patients with ALA. Controls were sera from 20 healthy people living in endemic areas with a high seroprevalence of antibodies to amoebas, and 20 patients with alcoholic hepatitis (AH) to rule out the cross‐reaction of Ehub with autoantibodies induced by liver damage. Antigens were trophozoite extract, glycoprotein Ehub and the recombinant protein E. histolytica recombinant ubiquitin (rEhub). The sera from healthy volunteers and patients with AH do not have antibodies to glycoprotein Ehub. Surprisingly, only the antibodies from patients with ALA recognized the glycoprotein Ehub, and some sera gave a faint reaction with the recombinant protein, especially because evolutionarily, the ubiquitin is conserved between species. This is the first report demonstrating that antibodies to ubiquitin Ehub are induced exclusively in patients with invasive amoebiasis, and the antibody response is mainly to the glycoprotein, indicating glycans are immunodominant. Inhibitors of the Ehub glycans could be potential treatment for amoebiasis by selectively damaging trophozoites.

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Characterization of N-glycosylations in Entamoeba histolytica ubiquitin

Cited by 6 publications

References 74 publications

Glycan moieties in Entamoeba histolytica ubiquitin are immunodominant

Glycan moieties in Entamoeba histolytica ubiquitin are immunodominant

Golgi apparatus components in Entamoeba histolytica and Entamoeba dispar after monensin treatment

Ubiquitin of Entamoeba histolytica induces antibody response in patients with invasive amoebiasis

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