Polymorphism of the 35- and 50-kilodalton surface glycoconjugates of Trypanosoma cruzi metacyclic trypomastigotes

Mortara, Renato Arruda; Silva, S da; Araguth, Marcia F.; Blanco, S A; Yoshida, Nobuko

doi:10.1128/iai.60.11.4673-4678.1992

Cited by 62 publications

(40 citation statements)

References 26 publications

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“…The samples (1 × 10 7 per lane) were analysed by SDS‐PAGE (12% acrylamide), transferred to nitrocellulose membranes and blocked with 1% BSA in PBS for 2 h at RT. The following antibodies to metacyclic surface glycoproteins were used: mAb 2B10 (1:200), which recognizes mucins (Mortara et al ., 1992); mAb 5E7 (1:100), which recognizes the 90 kDa glycoprotein (Teixeira and Yoshida, 1986); mAb 3F 6 (1:100), which recognizes 82 kDa and 30 kDa glycoproteins (Cortez et al ., 2003), and rabbit antibodies against CTR. Bound antibodies were detected by ECL (Amersham Biosciences) using standard protocols.…”

Section: Methodsmentioning

confidence: 99%

Expression of trypomastigote trans-sialidase in metacyclic forms of Trypanosoma cruzi increases parasite escape from its parasitophorous vacuole

et al. 2006

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SummaryTrypanosoma cruzi actively invades mammalian cells by forming parasitophorous vacuoles (PVs). After entry, the parasite has to escape from these vacuoles in order to replicate inside the host cell cytosol. Trans -sialidase (TS), a parasite enzyme that is used to obtain sialic acid from host glycoconjugates, has been implicated in cell invasion and PV exit, but how the enzyme acts in these processes is still unknown. Here we show that trypomastigotes derived from infected mammalian cells express and release 20 times more TS activity than axenic metacyclic trypomastigotes, which correspond to the infective forms derived from the insect vector. Both forms have the same capacity to invade mammalian cells, but cell derived trypomastigotes exit earlier from the vacuole. To test whether high TS expression is responsible for this increased exit from the PV, trypomastigote TS was expressed on the surface of metacyclic forms. Transfected and non-transfected metacyclics attached to and invaded HeLa or CHO cells equally. In contrast, metacyclics expressing TS on the surface escaped earlier from the vacuole than non-transfected metacyclics, or metacyclics expressing TS in their cytoplasm. Sialic acid may act as a barrier, which is removed by surface and/or secreted TS, because all types of parasites escaped earlier from the vacuoles of sialic acid-deficient Lec 2 cells than wild-type CHO cells. In addition, trypomastigotes and metacyclic forms expressing TS differentiated earlier into amastigotes. These results indicate that the increased expression of TS in cell-derived trypomastigotes is responsible for the earlier exit from the PV to the cytoplasm and their subsequent differentiation into amastigotes.

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Section: Methodsmentioning

confidence: 99%

Expression of trypomastigote trans-sialidase in metacyclic forms of Trypanosoma cruzi increases parasite escape from its parasitophorous vacuole

et al. 2006

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“…As shown in figure 2 D, the antibodies directed to the molecular tag detected the recombinant mucin only in the samples retained in the column. Possible contamination of the samples with epimastigote endogenous mucins was checked using the monoclonal antibody 3F5, that specifically detects the epimastigote endogenous 35/50 kDa mucins (39). This antibody did not detect the 35-50 kDa mucins in the sample retained by the anti-tag antibody column, indicating that the recombinant mucin was not contaminated with endogenous mucins (data not shown).…”

Section: The Repetitive Member Of the Tcmuc Family Is Expressed In Trmentioning

confidence: 99%

Trypanosoma cruzi Surface Mucins with Exposed Variant Epitopes

Pollevick¹,

Noia²,

Salto³

et al. 2000

Journal of Biological Chemistry

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The protozoan parasite Trypanosoma cruzi, the agent of Chagas disease, has a large number of mucin molecules on its surface, whose expression is regulated during the life cycle. These mucins are the main acceptors of sialic acid, a monosaccharide that is required by the parasite to infect and survive in the mammalian host. A large mucin-like gene family named TcMUC containing about 500 members has been identified previously in T. cruzi. TcMUC can be divided into two subfamilies according to the presence or absence of tandem repeats in the central region of the genes. In this work, T. cruzi parasites were transfected with one tagged member of each subfamily. Only the product from the gene with repeats was highly O-glycosylated in vivo. The O-linked oligosaccharides consisted mainly of beta-d-Galp(1-->4)GlcNAc and beta-d-Galp(1-->4)[beta-d-Galp(1-->6)]-d-GlcNAc. The same glycosyl moieties were found in endogenous mucins. The mature product was anchored by glycosylphosphatidylinositol to the plasma membrane and exposed to the medium. Sera from infected mice recognized the recombinant product of one repeats-containing gene thus showing that they are expressed during the infection. TcMUC genes encode a hypervariable region at the N terminus. We now show that the hypervariable region is indeed present in the exposed mature N termini of the mucins because sera from infected hosts recognized peptides having sequences from this region. The results are discussed in comparison with the mucins from the insect stages of the parasite (Di Noia, J. M., D'Orso, I., Sánchez, D. O., and Frasch, A. C. C. (2000) J. Biol. Chem. 275, 10218-10227) which do not have variable regions.

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“…Not only are metacyclic and blood trypomastigotes apparently equipped with distinct sets of molecules for target cell recognition and/or invasion, but it is also possible that different T. cruzi strains do not use the same repertoire of surface components to enter host cells. Furthermore, expression of variant forms of surface antigens has been observed among T. cruzi strains (14,15), adding another variable to an already complicated picture.…”

mentioning

confidence: 99%

Involvement of the stage-specific 82-kilodalton adhesion molecule of Trypanosoma cruzi metacyclic trypomastigotes in host cell invasion

et al. 1993

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This study provides several pieces of evidence indicating that 3F6-Ag, identified by monoclonal antibody (MAb) 3F6 as a stage-specific glycoprotein of approximately 82 kDa on the surface of metacyclic trypomastigotes of different Trypanosoma cruzi strains, promotes the entry of parasites into host cells through a ligand-receptor type interaction. First, invasion of Vero cells by metacyclic trypomastigotes of both CL and Tulahuen strains was significantly inhibited by MAb 3F6 or its Fab fragments. Second, purified 3F6-Ag bound to Vero cells in a dose-dependent and saturable fashion. Third, soluble 3F6-Ag reduced the infection of Vero cells by metacyclic forms of CL and Tulahuen strains by 90 to 97 and 50%Yo, respectively. Unrelated proteins, as well as extracellular matrix components, such as heparan sulfate and collagen, had no effect. Our studies also show that in the Tulahuen strain, 10D8-Ag, a 35/50-kDa glycoprotein identified by MAb 10D8, participates in target cell invasion, confirming previous observations, but the variant form of 10D8-Ag expressed by highly invasive CL strain metacyclic trypomastigotes appears to be irrelevant. Overall, our results indicate that the

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Polymorphism of the 35- and 50-kilodalton surface glycoconjugates of Trypanosoma cruzi metacyclic trypomastigotes

Abstract: In this study, we examined the immunochemical properties of the 35and 50-kDa (35/50-kDa) surface

Cited by 62 publications

References 26 publications

Expression of trypomastigote trans-sialidase in metacyclic forms of Trypanosoma cruzi increases parasite escape from its parasitophorous vacuole

Expression of trypomastigote trans-sialidase in metacyclic forms of Trypanosoma cruzi increases parasite escape from its parasitophorous vacuole

Trypanosoma cruzi Surface Mucins with Exposed Variant Epitopes

Involvement of the stage-specific 82-kilodalton adhesion molecule of Trypanosoma cruzi metacyclic trypomastigotes in host cell invasion

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