Analysis of proteins from membrane and soluble fractions of Giardia duodenalis trophozoites of two Brazilian axenic strains

Guimarães, Semíramis; Sogayar, Maria Inês T. L.; Franco, Marcello

doi:10.1590/s0036-46652002000500001

Cited by 5 publications

(4 citation statements)

References 26 publications

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“…The glycoprotein of 58 kDa detected in the present study showed similar or close to the molecular mass of a previously identified secreted protein (Kaur et al 1999). Other authors have reported glycoproteins in membrane fractions of 59 and 81 kDa revealed by Concanavalin A (Con A), while in the watersoluble fraction a glycoprotein of 62 kDa of molecular mass was detected (Guimaraes et al 2003). The oxidation with metaperiodate is useful in the structural analysis of glycosylated molecules and has been used to elucidate the role of the carbohydrate portion of antigenic glycoprotein in the reactivity by serology (Schalling and van Leeuwen 1996).…”

Section: Discussionsupporting

confidence: 88%

Excreted/secreted glycoproteins of G. intestinalis play an essential role in the antibody response

Morelle

et al. 2006

Parasitol Res

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In the present work, glycoproteins in the excretory/secretory products of G. intestinalis were identified and the reactivity in serum of immunized mice with these molecules was evaluated by western blotting before and after chemical treatment or enzymatic deglycosylation. Glycoproteins of 58 and 63 kDa were revealed in E/S products after periodic acid-Schiff (PAS) stain. Studies of carbohydrate specificity using digoxigenin-labeled lectins, revealed the presence of O-glycans and N-glycans. Chemical treatment of excretory/secretory products with sodium meta-periodate or enzymatic deglycosylation with N-glycosidase F reduced the reactivity in serum for proteins of 36, 58 and 63 kDa, respectively. These results show the presence of glycoproteins in E/S products of G. intestinalis and suggest that the antibody response is directed against glycoepitopes. The expression of carbohydrate moieties in the E/S-G. intestinalis may play an essential role in the antibody response and may be a target for serodiagnosis or immune intervention in human giardiasis.

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Section: Discussionsupporting

confidence: 88%

Excreted/secreted glycoproteins of G. intestinalis play an essential role in the antibody response

Morelle

et al. 2006

Parasitol Res

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“…Previously, Soliman et al identified at least eleven proteins with molecular weights of 170 to 31kDa respectively [10]. Also, Guimarães et al determined by electrophoretic profile a fraction of Brazilian isolates, reporting the presence of 16 bands with molecular weights between 122 and 10kDa [11]. More recently, our group identified in the soluble extract bands between 137 and 14kDa reacting with the specific IgA anti-Giardia in the serum of infected children [13].…”

Section: Discussionmentioning

confidence: 56%

“…Individuals with active giardiasis display higher levels of specific IgG but lower levels of IgM than do subjects free of established infection, and raised levels of Giardia specific IgG and IgA have been correlated with the presence or absence of parasites [8,9]. These and other investigators have quantified the levels of IgG, IgM, and IgE responses to different antigens [10][11][12], but curiously, there have been fewer reports in the literature on the levels of IgA antibody responses in human giardiasis [13]. Investigations have indicated the protective role of the specific IgA antibodies [14,15].…”

Section: Introductionmentioning

confidence: 99%

Parasite-specific IgA response in infected children by Giardia intestinalis from rural communities of Venezuela.

Durán¹,

Jiménez²,

Pocaterra³

et al. 2018

J Parasit Dis Diagn Ther

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Giardiasis is an infection caused by Giardia intestinalis into the small intestine that affects children in school age. The aim of the work was evaluated the specific IgA anti-Giardia antibodies in serum of children from rural communities were evaluated 100 children of 3 to 13 years old and measurement the levels of IgA antibody response against immunodominant antigens of Giardia intestinalis by ELISA and Westernblot. The soluble extract of Giardia intestinalis and fractions were obtained by differential centrifugation. Electrophoretic pattern showed several proteins from 205 to 14kDa, and sera of infected children recognized proteins of 205, 176, a region from 76 to 41kDa, and a band of 23kDa in the fraction 2. The IgA antibody response anti-Giardia for to soluble extract was higher in infected children compared to uninfected children (0.29 ± 0.16 vs. 0.07 ± 0.04; p ≤ 0.05). The IgA antibody response against the fraction 2 was higher in infected group than controls (1.0 ± 0.2 vs. 0.75 ± 0.26; p ≥ 0.05), the fraction 3 showed similar response to the soluble extract (0.45 ± 0.12 vs. 0.3 ± 0.12; p ≥ 0.05). The infection by Giardia intestinalis produce specific IgA antibodies directed to the proteins of the fraction 2. These proteins could be tested as antigens for serological diagnosis of giardiasis.

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“…To date, the intracellular localization of giardins in G. lamblia has been performed using rabbit polyclonal antisera or by the use of epitope tagged α-giardins [19,26]. However, both these methods have limitations when attempting to study assemblages A and B because polyclonal antibodies have shown cross-reaction with other proteins, while transfection experiments are difficult to carry out on GS assemblages [27].…”

Section: Introductionmentioning

confidence: 99%

Immunodominant proteins α-1 giardin and β-giardin are expressed in both assemblages A and B of Giardia lamblia

et al. 2011

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BackgroundTo date, eight assemblages of Giardia lamblia have been described, but only assemblages A and B are known to infect humans. Despite the fact that the genomic, biological, and clinical differences found between these two assemblages has raised the possibility that they may be considered different species, there is relatively limited information on their phenotypic differences. In the present study, we developed monoclonal antibodies against alpha-1 and beta giardin, two immunodominant proteins produced during G. lamblia infection, and studied their expression and localization in WB (assemblage A) and GS trophozoites (assemblage B).ResultsThe polyclonal antibodies generated against WB trophozoites, particularly those recognizing intracellular proteins as well as the proteins present at the plasma membrane (variable-specific surface proteins), showed cross-reactivity with intracellular proteins in GS trophozoites. The use of monoclonal antibodies against beta giardin indicated ventral disc localization, particularly at the periphery in WB trophozoites. Interestingly, although beta giardin was also restricted to the ventral disc in GS trophozoites, the pattern of localization clearly differed in this assemblage. On the other hand, monoclonal antibodies against alpha-1 giardin showed plasma membrane localization in both assemblages with the bare area of GS trophozoites also being distinguished. Moreover, the same localization at the plasma membrane was observed in Portland-1 (Assemblage A) and in P15 (Assemblage E) trophozoites.ConclusionsWe found differences in localization of the beta giardin protein between assemblages A and B, but the same pattern of localization of alpha-1 giardin in strains from Assemblages A, B and E. These findings reinforce the need for more studies based on phenotypic characteristics in order to disclose how far one assemblage is from the other.

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Analysis of proteins from membrane and soluble fractions of Giardia duodenalis trophozoites of two Brazilian axenic strains

Cited by 5 publications

References 26 publications

Excreted/secreted glycoproteins of G. intestinalis play an essential role in the antibody response

Excreted/secreted glycoproteins of G. intestinalis play an essential role in the antibody response

Parasite-specific IgA response in infected children by Giardia intestinalis from rural communities of Venezuela.

Immunodominant proteins α-1 giardin and β-giardin are expressed in both assemblages A and B of Giardia lamblia

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