Meeting Abstract
Coral diseases outbreaks have been rapidly increasing on reefs worldwide. Our understanding of how corals respond to the agents causing these diseases remains limited. It is unknown if corals possess a form of immunological priming which would allow them to respond faster to secondary encounters with the same pathogen. In order to test this hypothesis we used the cnidarian model system, Exaiptasia pallida and challenged the anemones with the coral pathogen Vibrio coralliilyticus under sub-lethal conditions followed subsequently with a lethal challenge. The results indicate that E. pallida displays a form of immunological memory as primed anemones showed an increased survival compared to non-primed anemones during a lethal challenge. We further aimed to identify proteins involved in this immunological memory response by comparing anemones that were exposed to a sub-lethal bacterial challenge to those that we not prior to the lethal challenge. The lapsed time between sub-lethal and lethal challenge was 4 weeks. Total extracted proteins were examined using a 2D DIGE expression profile. The analysis revealed that a molecular response was significantly associated with the immunological priming phenomenon. We discovered 88 differentially expressed proteins between the treatments with 50 of them up regulated in primed anemones. Of these differentially expressed proteins identified on the gels, 25 were selected for further identification using mass spectrometry. The molecular response associated with the immunological priming documented in this study suggests a complex cellular regulation involving various proteins, including heat shock protein 70, ribosomal protein 10 and sacsin. Furthermore we propose a working model to explain the molecular mechanism mediating immunological memory in this basal metazoan.
