The term Colony Collapse Disorder describes the loss of hives due to the disappearance or death of mature worker bees leading to the depopulation and ultimate death of a honey bee colony. Over a quarter of hives in the USA were lost to CCD last year and equivalent losses were reported across continental Europe and Asia. If CCD incidence persists over the next years it could conceivably signal the loss of the major pollinators of crops and ultimately the death of civilization as we know it.
Although the causes of CCD are multi-factorial, environmental parameters uniformly appear to affect the efficiency of the honey bees’ immune responses, rendering individuals vulnerable to infections. Moreover, the honey bee genome, which was sequenced in 2006, codes for a reduced number of pathogen recognition molecules making bees uniquely susceptible to infection.
The key event in any immune response is the activation of the appropriate signaling pathway that will either lead to the production of antimicrobial substances or the orchestration of antimicrobial action. Activation of an innate immune pathway depends on the production of a stable and lasting initiation signal at the surface of effector cells and is depended on the recognition of potentially harmful non-self substances. In the honey bee, as in other insects, an arsenal of specialized molecules is constitutively resident on or near the cell surface for the express purposes of procuring, recognizing and reacting to potential pathogens. However, we know very little of their structure or their atomic interactions.
We will target Pathogen Pattern Recognition Receptors of the honey bee. Synthetic genes will be supplied and target domains will be cloned, over-expressed and purified in both bacterial and insect cells using high throughput cloning technology on-site. Soluble constructs will be crystallized and diffraction-worthy crystals will be used to collect data in-house and at synchrotron sites. We will use the resulting atomic models to compare against known structures that should allow us to usefully analyze the efficiency of aspects of the honey bee immune system.
We hope this research will not only supply an adequate tracking system of immunity prowess in honey bee colonies but will also contribute to the understanding of the molecular determinants of innate immunity in higher vertebrates and their relevance to inflammation and vaccine development.
Our laboratory specializes in protein X-ray crystallography which enables us to look at the 3-D structure of immunity-specific bio-molecules and relate their particular features to their anti-pathogen potential. Students will have to opportunity to gain experience in molecular cloning, recombinant protein production in both bacterial and mammalian expression systems, purification of proteins through fast protein liquid chromatography techniques, crystallization of protein complexes using state-of-the-art crystallization facilities, and structure determination and analysis.
A gamut of associated biophysical techniques will also be employed including dynamic and static light scattering, analytical ultra-centrifugation, isothermal calorimetry and surface plasmon resonance.
Protein Science & Structural Biology and Immunology & Infectious Disease
Project reference number: 219
| Name | Department | Institution | Country | |
|---|---|---|---|---|
| Dr Maria Harkiolaki | Structural Biology | Oxford University | UK | maria@strubi.ox.ac.uk |
There are no publications listed for this DPhil project.