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Transcriptomic basis for an antiserum against Micrurus corallinus (coral snake) venom.

Leão LI, Ho PL, Junqueira-de-Azevedo Ide L - BMC Genomics (2009)

Bottom Line: Each class included an assortment of isoforms, some showing evidence of alternative splicing and domain deletions.The immunological response showed that the sera from the immunized animals were able to recognize the recombinant antigens.In fact, the selected candidates provided an initial evidence of the feasibility of this approach, which is less costly and not dependent on the availability of the venom.

View Article: PubMed Central - HTML - PubMed

Affiliation: Centro de Biotecnologia, Instituto Butantan, São Paulo, SP, Brazil. lucianaleao@butantan.gov.br

ABSTRACT

Background: Micrurus corallinus (coral snake) is a tropical forest snake belonging to the family Elapidae. Its venom shows a high neurotoxicity associated with pre- and post-synaptic toxins, causing diaphragm paralysis, which may result in death. In spite of a relatively small incidence of accidents, serum therapy is crucial for those bitten. However, the adequate production of antiserum is hampered by the difficulty in obtaining sufficient amounts of venom from a small snake with demanding breeding conditions. In order to elucidate the molecular basis of this venom and to uncover possible immunogens for an antiserum, we generated expressed sequences tags (ESTs) from its venom glands and analyzed the transcriptomic profile. In addition, their immunogenicity was tested using DNA immunization.

Results: A total of 1438 ESTs were generated and grouped into 611 clusters. Toxin transcripts represented 46% of the total ESTs. The two main toxin classes consisted of three-finger toxins (3FTx) (24%) and phospholipases A(2) (PLA(2)s) (15%). However, 8 other classes of toxins were present, including C-type lectins, natriuretic peptide precursors and even high-molecular mass components such as metalloproteases and L-amino acid oxidases. Each class included an assortment of isoforms, some showing evidence of alternative splicing and domain deletions. Five antigenic candidates were selected (four 3FTx and one PLA(2)) and used for a preliminary study of DNA immunization. The immunological response showed that the sera from the immunized animals were able to recognize the recombinant antigens.

Conclusion: Besides an improvement in our knowledge of the composition of coral snake venoms, which are very poorly known when compared to Old World elapids, the expression profile suggests abundant and diversified components that may be used in future antiserum formulation. As recombinant production of venom antigens frequently fails due to complex disulfide arrangements, DNA immunization may be a viable alternative. In fact, the selected candidates provided an initial evidence of the feasibility of this approach, which is less costly and not dependent on the availability of the venom.

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Relative proportion of each category of product found in M. corallinus venom gland transcriptome. Toxin, Non-toxin and No Hit categories are, respectively, clusters matching GenBank snake toxin sequences, non snake toxin sequences, and any sequence with an e-value < 10e-05 on Blastx search or inconclusive nucleotide matches on Blastn. Non-toxins are categorized by their cellular function, whereas toxins by their structural type. Percentages of total ESTs and of the ESTs in the category (in parentheses) are presented.
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Figure 1: Relative proportion of each category of product found in M. corallinus venom gland transcriptome. Toxin, Non-toxin and No Hit categories are, respectively, clusters matching GenBank snake toxin sequences, non snake toxin sequences, and any sequence with an e-value < 10e-05 on Blastx search or inconclusive nucleotide matches on Blastn. Non-toxins are categorized by their cellular function, whereas toxins by their structural type. Percentages of total ESTs and of the ESTs in the category (in parentheses) are presented.

Mentions: Among the 10 particular types of toxins observed (Figure 1), three-finger proteins (3FTx) are the most abundant transcripts, followed by type A2 phospholipase (PLA2). In smaller numbers are the C-type lectins and the precursor of natriuretic peptide (NP). The other classes of toxins are less abundant. The profile of putative cellular proteins (Figure 1, left) showed a pattern expected from a secretory gland. The most expressed of these transcripts are related to mRNA transcription and protein translation.


Transcriptomic basis for an antiserum against Micrurus corallinus (coral snake) venom.

Leão LI, Ho PL, Junqueira-de-Azevedo Ide L - BMC Genomics (2009)

Relative proportion of each category of product found in M. corallinus venom gland transcriptome. Toxin, Non-toxin and No Hit categories are, respectively, clusters matching GenBank snake toxin sequences, non snake toxin sequences, and any sequence with an e-value < 10e-05 on Blastx search or inconclusive nucleotide matches on Blastn. Non-toxins are categorized by their cellular function, whereas toxins by their structural type. Percentages of total ESTs and of the ESTs in the category (in parentheses) are presented.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2662881&req=5

Figure 1: Relative proportion of each category of product found in M. corallinus venom gland transcriptome. Toxin, Non-toxin and No Hit categories are, respectively, clusters matching GenBank snake toxin sequences, non snake toxin sequences, and any sequence with an e-value < 10e-05 on Blastx search or inconclusive nucleotide matches on Blastn. Non-toxins are categorized by their cellular function, whereas toxins by their structural type. Percentages of total ESTs and of the ESTs in the category (in parentheses) are presented.
Mentions: Among the 10 particular types of toxins observed (Figure 1), three-finger proteins (3FTx) are the most abundant transcripts, followed by type A2 phospholipase (PLA2). In smaller numbers are the C-type lectins and the precursor of natriuretic peptide (NP). The other classes of toxins are less abundant. The profile of putative cellular proteins (Figure 1, left) showed a pattern expected from a secretory gland. The most expressed of these transcripts are related to mRNA transcription and protein translation.

Bottom Line: Each class included an assortment of isoforms, some showing evidence of alternative splicing and domain deletions.The immunological response showed that the sera from the immunized animals were able to recognize the recombinant antigens.In fact, the selected candidates provided an initial evidence of the feasibility of this approach, which is less costly and not dependent on the availability of the venom.

View Article: PubMed Central - HTML - PubMed

Affiliation: Centro de Biotecnologia, Instituto Butantan, São Paulo, SP, Brazil. lucianaleao@butantan.gov.br

ABSTRACT

Background: Micrurus corallinus (coral snake) is a tropical forest snake belonging to the family Elapidae. Its venom shows a high neurotoxicity associated with pre- and post-synaptic toxins, causing diaphragm paralysis, which may result in death. In spite of a relatively small incidence of accidents, serum therapy is crucial for those bitten. However, the adequate production of antiserum is hampered by the difficulty in obtaining sufficient amounts of venom from a small snake with demanding breeding conditions. In order to elucidate the molecular basis of this venom and to uncover possible immunogens for an antiserum, we generated expressed sequences tags (ESTs) from its venom glands and analyzed the transcriptomic profile. In addition, their immunogenicity was tested using DNA immunization.

Results: A total of 1438 ESTs were generated and grouped into 611 clusters. Toxin transcripts represented 46% of the total ESTs. The two main toxin classes consisted of three-finger toxins (3FTx) (24%) and phospholipases A(2) (PLA(2)s) (15%). However, 8 other classes of toxins were present, including C-type lectins, natriuretic peptide precursors and even high-molecular mass components such as metalloproteases and L-amino acid oxidases. Each class included an assortment of isoforms, some showing evidence of alternative splicing and domain deletions. Five antigenic candidates were selected (four 3FTx and one PLA(2)) and used for a preliminary study of DNA immunization. The immunological response showed that the sera from the immunized animals were able to recognize the recombinant antigens.

Conclusion: Besides an improvement in our knowledge of the composition of coral snake venoms, which are very poorly known when compared to Old World elapids, the expression profile suggests abundant and diversified components that may be used in future antiserum formulation. As recombinant production of venom antigens frequently fails due to complex disulfide arrangements, DNA immunization may be a viable alternative. In fact, the selected candidates provided an initial evidence of the feasibility of this approach, which is less costly and not dependent on the availability of the venom.

Show MeSH
Related in: MedlinePlus