Presence of sialic acid in N-linked oligosaccharide chains and O-linked N-acetylglucosamine in cruzipain, the major cysteine proteinase of Trypanosoma cruzi

Barboza, Mariana; Duschak, Vilma G.; Cazzulo, Juán José; Lederkremer, Rosa M. de; Couto, Alicia S.

doi:10.1016/s0166-6851(02)00287-6

Cited by 14 publications

(26 citation statements)

References 18 publications

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“…The interaction between T. cruzi and Siglec-E resulted in a reduction of cytokine production as well as an unpaired T cell activation [23]. Therefore, taking into account that we have previously demonstrated the presence of sialic acid [19] and sulfated oligosaccharides [11] in Cz, that these sulfated structures play an important role in the immune response of the host [20], and that human Siglec-8 and Siglec-9 showed significant interactions with several sulfated sugars [27], and we evaluated the interaction between this sulfate-containing sialylated parasite molecule and mouse Siglec-E-Fc fusion molecules with the aim to investigate the involvement of sulfate moieties of Cz on the immunomodulatory effects of T. cruzi. The studies performed reflected the participation of the sulfated moieties of Cz in the Siglec-E-Fc interaction.…”

Section: Introductionmentioning

confidence: 90%

“…The C-T domain was obtained by self-proteolysis of highly purified Cz active preparations and purified by gel filtration in a Biogel P-30 column as previously described [19].…”

Section: Purification Of Cz and C-t Domainmentioning

confidence: 99%

“…Moreover, it is a relevant virulence factor [12][13][14], which has been extensively studied as protease, glycoprotein and antigen [15], evaluated as candidate for vaccine development [16] and considered a very promising target for chemotherapy of the disease [17,18]. In the last years, we have demonstrated the presence of a complex N-glycosidic oligosaccharide bearing sialic acid in Cz [19] and sulfated high-mannosetype oligosaccharides on the unique N-glycosylation site of the C-T domain [11]. Furthermore, we reported that these sulfate moieties are targets for specific immune responses [20] and that subjects chronically infected with T. cruzi mount specific humoral immune responses to this sulfated glycoprotein.…”

Section: Introductionmentioning

confidence: 99%

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Involvement of sulfates from cruzipain, a major antigen of Trypanosoma cruzi, in the interaction with immunomodulatory molecule Siglec-E

Ferrero

Heins

Soprano

et al. 2015

Med Microbiol Immunol

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In order to investigate the involvement of sulfated groups in the Trypanosoma cruzi host-parasite relationship, we studied the interaction between the major cysteine proteinase of T. cruzi, cruzipain (Cz), a sulfate-containing sialylated molecule and the sialic acid-binding immunoglobulin like lectin-E (Siglec-E). To this aim, ELISA, indirect immunofluorescence assays and flow cytometry, using mouse Siglec-E-Fc fusion molecules and glycoproteins of parasites, were performed. Competition assays verified that the lectins, Maackia amurensis II (Mal II) and Siglec-E-Fc, compete for the same binding sites. Taking into account that Mal II binding remains unaltered by sulfation, we established this lectin as sialylation degree control. Proteins of an enriched microsomal fraction showed the highest binding to Siglec-E as compared with those from the other parasite subcellular fractions. ELISA assays and the affinity purification of Cz by a Siglec-E column confirmed the interaction between both molecules. The significant decrease in binding of Siglec-E-Fc to Cz and to its C-terminal domain (C-T) after desulfation of these molecules suggests that sulfates contribute to the interaction between Siglec-E-Fc and these glycoproteins. Competitive ELISA assays confirmed the involvement of sulfated epitopes in the affinity between Siglec-E and Cz, probably modified by natural protein environment. Interestingly, data from flow cytometry of untreated and chlorate-treated parasites suggested that sulfates are not primary receptors, but enhance the binding of Siglec-E to trypomastigotic forms. Altogether, our findings support the notion that sulfate-containing sialylated glycoproteins interact with Siglec-E, an ortholog protein of human Siglec-9, and might modulate the immune response of the host, favoring parasitemia and persistence of the parasite.

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Section: Introductionmentioning

confidence: 90%

“…The C-T domain was obtained by self-proteolysis of highly purified Cz active preparations and purified by gel filtration in a Biogel P-30 column as previously described [19].…”

Section: Purification Of Cz and C-t Domainmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Involvement of sulfates from cruzipain, a major antigen of Trypanosoma cruzi, in the interaction with immunomodulatory molecule Siglec-E

Ferrero

Heins

Soprano

et al. 2015

Med Microbiol Immunol

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“…We have performed a literature search using the special queries function 'Retracted Publications' and 'Retraction of Publication' on MEDLINE (search filters: human and animal studies; English; from 1 January 1966 to 18 February 2008) and, additionally, looked for full original publication and retraction notice available, indicating that the publication had been retracted for reason of misconduct. Including not just human but animal studies as well, we found articles retracted from Brazil (duplication) 5 and Argentina (duplication) 6 . However we are aware that many more retractions have occurred.…”

Section: I a L D I S T R I B U T I O N U N A U T H O R I Z E D U S mentioning

confidence: 99%

Publication misconduct and plagiarism retractions: a Latin American perspective

Alfaro-Toloza

Mayta‐Tristán

Rodríguez-Morales

2012

Current Medical Research and Opinion

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“…GlcNAc and Gal residues are likely added conventionally in the Golgi apparatus (23), but sialic acids are transferred from host glycans (24) by cell surface trans-sialidases (13,16). Glycosylation is protein specific, as evidenced by cruzipain, which transits the Golgi-endosomal pathway, accumulates in late endosomes referred to as lysosome-related organelles or reservosomes (25), and contains unmodified O-linked GlcNAc residues and sialic acid-terminated N-linked glycan chains (26). The coat formed by glycoproteins and glycoinositolphospholipids protects epimastigotes from proteases in the insect vector intestinal tract (27) and supports survival of MCTs during vector-borne transmission and penetration of the gastric mucosa of the mammalian host (7).…”

mentioning

confidence: 99%

Golgi UDP-GlcNAc:Polypeptide O -α- N -Acetyl- d -Glucosaminyltransferase 2 (TcOGNT2) Regulates Trypomastigote Production and Function in Trypanosoma cruzi

et al. 2014

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e All life cycle stages of the protozoan parasite Trypanosoma cruzi are enveloped by mucin-like glycoproteins which, despite major changes in their polypeptide cores, are extensively and similarly O-glycosylated. O-Glycan biosynthesis is initiated by the addition of ␣GlcNAc to Thr in a reaction catalyzed by Golgi UDP-GlcNAc:polypeptide O-␣-N-acetyl-D-glucosaminyltransferases (pp␣GlcNAcTs), which are encoded by TcOGNT1 and TcOGNT2. We now directly show that TcOGNT2 is associated with the Golgi apparatus of the epimastigote stage and is markedly downregulated in both differentiated metacyclic trypomastigotes (MCTs) and cell culture-derived trypomastigotes (TCTs). The significance of downregulation was examined by forced continued expression of TcOGNT2, which resulted in a substantial increase of TcOGNT2 protein levels but only modestly increased pp␣GlcNAcT activity in extracts and altered cell surface glycosylation in TCTs. Constitutive TcOGNT2 overexpression had no discernible effect on proliferating epimastigotes but negatively affected production of both types of trypomastigotes. MCTs differentiated from epimastigotes at a low frequency, though they were apparently normal based on morphological and biochemical criteria. However, these MCTs exhibited an impaired ability to produce amastigotes and TCTs in cell culture monolayers, most likely due to a reduced infection frequency. Remarkably, inhibition of MCT production did not depend on TcOGNT2 catalytic activity, whereas TCT production was inhibited only by active TcOGNT2. These findings indicate that TcOGNT2 downregulation is important for proper differentiation of MCTs and functioning of TCTs and that TcOGNT2 regulates these functions by using both catalytic and noncatalytic mechanisms.

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Presence of sialic acid in N-linked oligosaccharide chains and O-linked N-acetylglucosamine in cruzipain, the major cysteine proteinase of Trypanosoma cruzi

Cited by 14 publications

References 18 publications

Involvement of sulfates from cruzipain, a major antigen of Trypanosoma cruzi, in the interaction with immunomodulatory molecule Siglec-E

Involvement of sulfates from cruzipain, a major antigen of Trypanosoma cruzi, in the interaction with immunomodulatory molecule Siglec-E

Publication misconduct and plagiarism retractions: a Latin American perspective

Golgi UDP-GlcNAc:Polypeptide O -α- N -Acetyl- d -Glucosaminyltransferase 2 (TcOGNT2) Regulates Trypomastigote Production and Function in Trypanosoma cruzi

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