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Published on: July 11, 2015
Expression and immunological evaluation of elongation factor Tu of Streptococcus suis serotype 2
Abstract:
Streptococcus suis serotype 2 (SS2) is considered as a major pathogen that causes sepsis and meningitis in piglets and humans, but knowledge of its antigenic proteins remains limited so far. The surface-related proteins of pathogens often play significant roles in bacterium-host interactions and infection. Here, we obtained the elongation factor Tu (EF-Tu) gene of Streptococcus suis and constructed the recombinant expression plasmid successfully. The target recombinant plasmid was then expressed in Escherichia coli and the immuno-protection of the recombinant protein was subsequently evaluated as well. The EF-Tu gene of Streptococcus suis is 1197 bp in length, encodes 398 amino acids. The target recombinant EF-Tu (rEF-Tu) protein can recognize the antiserum of Streptococcus suis and can provoke obvious humoral immune responses in rabbits and conferred protection to rabbits against Streptococcus suis ear-vein challenge, implying that the EF-Tu may be used as an attractive candidate antigen for a component of subunit vaccine.
Insights
Streptococcus suis serotype 2 (SS2) causes severe infections. Researchers identified elongation factor Tu (EF-Tu) as a potential antigen, demonstrating its ability to elicit immune responses and protect against SS2 challenge in rabbits.
Area of Science:
- Microbiology
- Immunology
- Veterinary Medicine
Background:
- Streptococcus suis serotype 2 (SS2) is a significant pathogen causing sepsis and meningitis in piglets and humans.
- Limited knowledge exists regarding SS2 antigenic proteins crucial for bacterium-host interactions.
Purpose of the Study:
- To investigate the potential of Streptococcus suis elongation factor Tu (EF-Tu) as a candidate antigen for vaccine development.
- To evaluate the immunogenicity and protective efficacy of recombinant EF-Tu (rEF-Tu) against SS2 infection.
Main Methods:
- The EF-Tu gene from Streptococcus suis was cloned and expressed in Escherichia coli to produce recombinant EF-Tu (rEF-Tu).
- The rEF-Tu protein's reactivity with SS2 antiserum was confirmed.
- Humoral immune responses and protective effects of rEF-Tu were assessed in rabbits following experimental SS2 challenge.
Main Results:
- The EF-Tu gene is 1197 bp, encoding a 398-amino acid protein.
- Recombinant EF-Tu (rEF-Tu) recognized SS2 antiserum.
- rEF-Tu induced significant humoral immune responses in rabbits and provided protection against SS2 ear-vein challenge.
Conclusions:
- Streptococcus suis EF-Tu is immunogenic and elicits protective immunity against SS2 infection.
- EF-Tu shows promise as a candidate antigen for developing a subunit vaccine against Streptococcus suis serotype 2.
