Limits...
Genomic analyses, gene expression and antigenic profile of the trans-sialidase superfamily of Trypanosoma cruzi reveal an undetected level of complexity.

Freitas LM, dos Santos SL, Rodrigues-Luiz GF, Mendes TA, Rodrigues TS, Gazzinelli RT, Teixeira SM, Fujiwara RT, Bartholomeu DC - PLoS ONE (2011)

Bottom Line: We demonstrated that all seven groups represented in the array are antigenic.A highly reactive peptide occurs in sixty TcS proteins including members of two new groups and may contribute to the known cross-reactivity of T. cruzi epitopes during infection.Taken together, our results contribute to a better understanding of the real complexity of the TcS family and open new avenues for investigating novel roles of this family during T. cruzi infection.

View Article: PubMed Central - PubMed

Affiliation: Departamento de Parasitologia, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.

ABSTRACT
The protozoan parasite Trypanosoma cruzi is the etiologic agent of Chagas disease, a highly debilitating human pathology that affects millions of people in the Americas. The sequencing of this parasite's genome reveals that trans-sialidase/trans-sialidase-like (TcS), a polymorphic protein family known to be involved in several aspects of T. cruzi biology, is the largest T. cruzi gene family, encoding more than 1,400 genes. Despite the fact that four TcS groups are well characterized and only one of the groups contains active trans-sialidases, all members of the family are annotated in the T. cruzi genome database as trans-sialidase. After performing sequence clustering analysis with all TcS complete genes, we identified four additional groups, demonstrating that the TcS family is even more heterogeneous than previously thought. Interestingly, members of distinct TcS groups show distinctive patterns of chromosome localization. Members of the TcSgroupII, which harbor proteins involved in host cell attachment/invasion, are preferentially located in subtelomeric regions, whereas members of the largest and new TcSgroupV have internal chromosomal locations. Real-time RT-PCR confirms the expression of genes derived from new groups and shows that the pattern of expression is not similar within and between groups. We also performed B-cell epitope prediction on the family and constructed a TcS specific peptide array, which was screened with sera from T. cruzi-infected mice. We demonstrated that all seven groups represented in the array are antigenic. A highly reactive peptide occurs in sixty TcS proteins including members of two new groups and may contribute to the known cross-reactivity of T. cruzi epitopes during infection. Taken together, our results contribute to a better understanding of the real complexity of the TcS family and open new avenues for investigating novel roles of this family during T. cruzi infection.

Show MeSH

Related in: MedlinePlus

Antigenic profile of TcS peptides.The top panel shows a representative result of immunoblot employing a SPOT synthesis membrane and pools of sera from T. cruzi-infected mice (A) and from control uninfected mice (B). The reaction was revealed with secondary anti-total IgG antibody. The bottom panel shows the relative intensity of the signal of each spot estimated based on a comparison of the reactivity in immunoblots with sera from T. cruzi-infected mice to the background levels, determined by reactivity with sera from uninfected mice. A signal was scored as reactive when relative intensity (RI)≥2. The peptides analyzed for each TcS group are as follows: TcS group I, D5–D10; TcS group III, C9-D4; TcS group IV, B5-C1, C3; TcS group V, A1, C2, C3, C7; TcS group VI, C2–C8; TcS group VII, A9-B4; TcS group VIII, A2–A8.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3198458&req=5

pone-0025914-g007: Antigenic profile of TcS peptides.The top panel shows a representative result of immunoblot employing a SPOT synthesis membrane and pools of sera from T. cruzi-infected mice (A) and from control uninfected mice (B). The reaction was revealed with secondary anti-total IgG antibody. The bottom panel shows the relative intensity of the signal of each spot estimated based on a comparison of the reactivity in immunoblots with sera from T. cruzi-infected mice to the background levels, determined by reactivity with sera from uninfected mice. A signal was scored as reactive when relative intensity (RI)≥2. The peptides analyzed for each TcS group are as follows: TcS group I, D5–D10; TcS group III, C9-D4; TcS group IV, B5-C1, C3; TcS group V, A1, C2, C3, C7; TcS group VI, C2–C8; TcS group VII, A9-B4; TcS group VIII, A2–A8.

Mentions: Because the antigenicity of some members of the sialidase family was already reported [33], [34], we decided to investigate whether other peptides derived from the TcS family are also antigenic. To this end, we have performed linear B-cell epitope prediction on all 508 complete members of the TcS family. A total of 40 peptides with 15 residues, high prediction scores and high occurrences within the TcS group were synthesized in a solid support by the spot synthesis technique and screened with sera from animals infected with T. cruzi. The list of all peptides used in this study is shown in the Table S2. As shown in Figure 7, 11 TcS peptides derived from distinct groups displayed antigenic properties based on a cut-off signal well above background. In agreement with previous studies, peptides corresponding to the SAPA (D5 and D8) [33] and to the TsTc13 repeats (B5) [34] are highly antigenic. We have also identified new epitopes specific to the previously characterized TcSgroups I and IV (D9 and D10, and B10, respectively). At least one peptide from each of the new TcSgroups -V, VI, VII and VIII - was recognized by sera of infected animals (A1, C3, A10 and B4, and A5, respectively). The peptide C3 occurs in the largest number of members (60 in total) from the new TcS groups V and VI and from the previously characterized TcS groups II and IV.


Genomic analyses, gene expression and antigenic profile of the trans-sialidase superfamily of Trypanosoma cruzi reveal an undetected level of complexity.

Freitas LM, dos Santos SL, Rodrigues-Luiz GF, Mendes TA, Rodrigues TS, Gazzinelli RT, Teixeira SM, Fujiwara RT, Bartholomeu DC - PLoS ONE (2011)

Antigenic profile of TcS peptides.The top panel shows a representative result of immunoblot employing a SPOT synthesis membrane and pools of sera from T. cruzi-infected mice (A) and from control uninfected mice (B). The reaction was revealed with secondary anti-total IgG antibody. The bottom panel shows the relative intensity of the signal of each spot estimated based on a comparison of the reactivity in immunoblots with sera from T. cruzi-infected mice to the background levels, determined by reactivity with sera from uninfected mice. A signal was scored as reactive when relative intensity (RI)≥2. The peptides analyzed for each TcS group are as follows: TcS group I, D5–D10; TcS group III, C9-D4; TcS group IV, B5-C1, C3; TcS group V, A1, C2, C3, C7; TcS group VI, C2–C8; TcS group VII, A9-B4; TcS group VIII, A2–A8.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3198458&req=5

pone-0025914-g007: Antigenic profile of TcS peptides.The top panel shows a representative result of immunoblot employing a SPOT synthesis membrane and pools of sera from T. cruzi-infected mice (A) and from control uninfected mice (B). The reaction was revealed with secondary anti-total IgG antibody. The bottom panel shows the relative intensity of the signal of each spot estimated based on a comparison of the reactivity in immunoblots with sera from T. cruzi-infected mice to the background levels, determined by reactivity with sera from uninfected mice. A signal was scored as reactive when relative intensity (RI)≥2. The peptides analyzed for each TcS group are as follows: TcS group I, D5–D10; TcS group III, C9-D4; TcS group IV, B5-C1, C3; TcS group V, A1, C2, C3, C7; TcS group VI, C2–C8; TcS group VII, A9-B4; TcS group VIII, A2–A8.
Mentions: Because the antigenicity of some members of the sialidase family was already reported [33], [34], we decided to investigate whether other peptides derived from the TcS family are also antigenic. To this end, we have performed linear B-cell epitope prediction on all 508 complete members of the TcS family. A total of 40 peptides with 15 residues, high prediction scores and high occurrences within the TcS group were synthesized in a solid support by the spot synthesis technique and screened with sera from animals infected with T. cruzi. The list of all peptides used in this study is shown in the Table S2. As shown in Figure 7, 11 TcS peptides derived from distinct groups displayed antigenic properties based on a cut-off signal well above background. In agreement with previous studies, peptides corresponding to the SAPA (D5 and D8) [33] and to the TsTc13 repeats (B5) [34] are highly antigenic. We have also identified new epitopes specific to the previously characterized TcSgroups I and IV (D9 and D10, and B10, respectively). At least one peptide from each of the new TcSgroups -V, VI, VII and VIII - was recognized by sera of infected animals (A1, C3, A10 and B4, and A5, respectively). The peptide C3 occurs in the largest number of members (60 in total) from the new TcS groups V and VI and from the previously characterized TcS groups II and IV.

Bottom Line: We demonstrated that all seven groups represented in the array are antigenic.A highly reactive peptide occurs in sixty TcS proteins including members of two new groups and may contribute to the known cross-reactivity of T. cruzi epitopes during infection.Taken together, our results contribute to a better understanding of the real complexity of the TcS family and open new avenues for investigating novel roles of this family during T. cruzi infection.

View Article: PubMed Central - PubMed

Affiliation: Departamento de Parasitologia, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.

ABSTRACT
The protozoan parasite Trypanosoma cruzi is the etiologic agent of Chagas disease, a highly debilitating human pathology that affects millions of people in the Americas. The sequencing of this parasite's genome reveals that trans-sialidase/trans-sialidase-like (TcS), a polymorphic protein family known to be involved in several aspects of T. cruzi biology, is the largest T. cruzi gene family, encoding more than 1,400 genes. Despite the fact that four TcS groups are well characterized and only one of the groups contains active trans-sialidases, all members of the family are annotated in the T. cruzi genome database as trans-sialidase. After performing sequence clustering analysis with all TcS complete genes, we identified four additional groups, demonstrating that the TcS family is even more heterogeneous than previously thought. Interestingly, members of distinct TcS groups show distinctive patterns of chromosome localization. Members of the TcSgroupII, which harbor proteins involved in host cell attachment/invasion, are preferentially located in subtelomeric regions, whereas members of the largest and new TcSgroupV have internal chromosomal locations. Real-time RT-PCR confirms the expression of genes derived from new groups and shows that the pattern of expression is not similar within and between groups. We also performed B-cell epitope prediction on the family and constructed a TcS specific peptide array, which was screened with sera from T. cruzi-infected mice. We demonstrated that all seven groups represented in the array are antigenic. A highly reactive peptide occurs in sixty TcS proteins including members of two new groups and may contribute to the known cross-reactivity of T. cruzi epitopes during infection. Taken together, our results contribute to a better understanding of the real complexity of the TcS family and open new avenues for investigating novel roles of this family during T. cruzi infection.

Show MeSH
Related in: MedlinePlus