Related Experiment Videos
Enolase from Streptococcus sobrinus is an immunosuppressive protein
Isabel Veiga-Malta1, Margarida Duarte, Márcia Dinis
1Instituto de Ciências Biomédicas de Abel Salazar, Rua do Campo Alegre 823, 4150-180 Porto, Portugal.
Cellular Microbiology
|December 18, 2003
Summary
Streptococcus sobrinus produces an enolase protein that suppresses the host immune response, aiding its colonization and survival. This specific immunosuppression involves promoting anti-inflammatory cytokines, indicating a novel mechanism for bacterial evasion.
Area of Science:
- Microbiology
- Immunology
- Molecular Biology
Background:
- Streptococcus sobrinus is a primary cause of dental caries.
- Bacterial survival strategies often involve immune evasion mechanisms.
- Specific antibody responses are crucial for host defense against pathogens.
Purpose of the Study:
- To clone and characterize a gene from S. sobrinus encoding an immunosuppressive protein.
- To investigate the role of this protein in modulating the host immune response.
- To understand the mechanism of immune suppression mediated by S. sobrinus.
Main Methods:
- Cloning the gene for the immunosuppressive protein.
- Expressing and purifying the recombinant protein in Escherichia coli.
- Assessing the effect of recombinant enolase on immune responses in mice.
- Measuring cytokine production (IL-10 and IFN-gamma).
Main Results:
- A gene encoding a 434-amino acid polypeptide homologous to enolases was cloned.
- Recombinant S. sobrinus enolase suppressed primary immune responses to T-cell dependent antigens in mice.
- The immunosuppressive effect was antigen-specific.
- Recombinant enolase stimulated interleukin-10 production but not IFN-gamma.
Conclusions:
- S. sobrinus enolase plays a role in suppressing the host's specific immune response.
- The mechanism involves promoting an anti-inflammatory cytokine profile.
- This immunosuppression facilitates S. sobrinus colonization and persistence.