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Analyzing and identifying novel B cell epitopes within Toxoplasma gondii GRA4.

Wang Y, Wang G, Ou J, Yin H, Zhang D - Parasit Vectors (2014)

Bottom Line: The potential B cell epitopes of GRA4 predicted by bioinformatics tools focused on six regions of GRA4, 52-77 aa, 93-112 aa, 127-157 aa, 178-201 aa, 223-252 aa and 314-333 aa.Three of the eleven peptides (amino acids 62-77, 233-252 and 314-333) tested were recognized by all sera.The identified epitopes may be useful for additional studies of epitope-based vaccines and diagnostic reagents.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730046, China. wangyh061001@163.com.

ABSTRACT

Background: The identification of specific epitopes targeted by the host antibody response is important for understanding the natural response to infection and for the development of epitope-based marker vaccines and diagnostic tools for toxoplasmosis. In this study, Toxoplasma gondii GRA4 epitopes were identified using software-based prediction and a synthetic peptide technique.

Methods: The complete GRA4 gene sequence was obtained from T. gondii of the Gansu Jingtai strain of tachyzoites. The potential B cell epitopes of GRA4 was predicted using the PROTEAN subroutine in the DNASTAR software package. The peptides with good hydrophilicity, high accessibility, high flexibility and strong antigenicity were chemically synthesized and assessed by ELISA using pig sera from different time points after infection.

Results: The potential B cell epitopes of GRA4 predicted by bioinformatics tools focused on six regions of GRA4, 52-77 aa, 93-112 aa, 127-157 aa, 178-201 aa, 223-252 aa and 314-333 aa. Eleven shorter peptides from the six regions were synthesized and assessed by ELISA using pig sera from different time points after infection. Three of the eleven peptides (amino acids 62-77, 233-252 and 314-333) tested were recognized by all sera.

Conclusions: We precisely located the T. gondii GRA4 epitopes using pig sera collected at different time points after infection. The identified epitopes may be useful for additional studies of epitope-based vaccines and diagnostic reagents.

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The secondary structures, flexibility, hydrophilicity, surface probability and antigenicity index forT. gondiiGRA4.
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Fig1: The secondary structures, flexibility, hydrophilicity, surface probability and antigenicity index forT. gondiiGRA4.

Mentions: Bioinformatics is important for predicting protein structure, function and biological characteristics. With the aid of software and databases for the prediction of epitopes, we can reduce the number of proteins of interest and significantly decrease the number of laboratory experiments. Bioinformatics has been widely used in the analysis of protein epitopes [50-54]. In the present study, the secondary structure of GRA4 was predicted by the Garnier–Robson and Chou–Fasman algorithms based on the sequence of the GRA4 gene. A flexibility plot, hydrophilicity plot, surface probability plot and antigenic index for GRA4 were obtained using the Karplus–Schulz, Kyte–Doolittle, Emini and Jameson–Wolf algorithms, respectively (Figure 1). The variability, fragment mobility, and hydrophilicity are important features of antigenic epitopes. The existence of flexible regions, such as coil and turn regions, provides powerful evidence for epitope identification [53,54]. Based on the results obtained with these methods, potential B cell epitopes on GRA4 were predicted, including 52–71 aa, 62–77 aa, 93–112 aa, 127–146 aa, 136–157 aa, 172–191 aa, 182–201 aa, 192–211 aa, 223–242 aa, 233–252 aa and 314–333 aa.Figure 1


Analyzing and identifying novel B cell epitopes within Toxoplasma gondii GRA4.

Wang Y, Wang G, Ou J, Yin H, Zhang D - Parasit Vectors (2014)

The secondary structures, flexibility, hydrophilicity, surface probability and antigenicity index forT. gondiiGRA4.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4195951&req=5

Fig1: The secondary structures, flexibility, hydrophilicity, surface probability and antigenicity index forT. gondiiGRA4.
Mentions: Bioinformatics is important for predicting protein structure, function and biological characteristics. With the aid of software and databases for the prediction of epitopes, we can reduce the number of proteins of interest and significantly decrease the number of laboratory experiments. Bioinformatics has been widely used in the analysis of protein epitopes [50-54]. In the present study, the secondary structure of GRA4 was predicted by the Garnier–Robson and Chou–Fasman algorithms based on the sequence of the GRA4 gene. A flexibility plot, hydrophilicity plot, surface probability plot and antigenic index for GRA4 were obtained using the Karplus–Schulz, Kyte–Doolittle, Emini and Jameson–Wolf algorithms, respectively (Figure 1). The variability, fragment mobility, and hydrophilicity are important features of antigenic epitopes. The existence of flexible regions, such as coil and turn regions, provides powerful evidence for epitope identification [53,54]. Based on the results obtained with these methods, potential B cell epitopes on GRA4 were predicted, including 52–71 aa, 62–77 aa, 93–112 aa, 127–146 aa, 136–157 aa, 172–191 aa, 182–201 aa, 192–211 aa, 223–242 aa, 233–252 aa and 314–333 aa.Figure 1

Bottom Line: The potential B cell epitopes of GRA4 predicted by bioinformatics tools focused on six regions of GRA4, 52-77 aa, 93-112 aa, 127-157 aa, 178-201 aa, 223-252 aa and 314-333 aa.Three of the eleven peptides (amino acids 62-77, 233-252 and 314-333) tested were recognized by all sera.The identified epitopes may be useful for additional studies of epitope-based vaccines and diagnostic reagents.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730046, China. wangyh061001@163.com.

ABSTRACT

Background: The identification of specific epitopes targeted by the host antibody response is important for understanding the natural response to infection and for the development of epitope-based marker vaccines and diagnostic tools for toxoplasmosis. In this study, Toxoplasma gondii GRA4 epitopes were identified using software-based prediction and a synthetic peptide technique.

Methods: The complete GRA4 gene sequence was obtained from T. gondii of the Gansu Jingtai strain of tachyzoites. The potential B cell epitopes of GRA4 was predicted using the PROTEAN subroutine in the DNASTAR software package. The peptides with good hydrophilicity, high accessibility, high flexibility and strong antigenicity were chemically synthesized and assessed by ELISA using pig sera from different time points after infection.

Results: The potential B cell epitopes of GRA4 predicted by bioinformatics tools focused on six regions of GRA4, 52-77 aa, 93-112 aa, 127-157 aa, 178-201 aa, 223-252 aa and 314-333 aa. Eleven shorter peptides from the six regions were synthesized and assessed by ELISA using pig sera from different time points after infection. Three of the eleven peptides (amino acids 62-77, 233-252 and 314-333) tested were recognized by all sera.

Conclusions: We precisely located the T. gondii GRA4 epitopes using pig sera collected at different time points after infection. The identified epitopes may be useful for additional studies of epitope-based vaccines and diagnostic reagents.

Show MeSH
Related in: MedlinePlus