A model on the role of odorant binding proteins in social immunity

We investigated mechanisms of social immunity in Apis mellifera. A. mellifera plays a crucial role in Agriculture as a pollinator of a variety of fruits and crops –the estimated contribution of honey bees to Canadian agriculture exceeds $2 billion. Honey bee pathogens trigger individual and colony level immune responses that vary between populations. Proteomic and pathway analysis indicated that the response to Varroa destructor, the most damaging threat of honey bees, is linked to proteins involved in the larvae response to Varroa and the viruses it vectors, and to odorant recognition processes in the nurse antennae. Combining our proteomics results with in vitro binding assays of semiochemicals to specific odorant binding proteins  as well as with published data, we developed a model that hypothesizes the mechanisms involved in social immunity. This model suggests the release of metabolic signatures by the affected host larvae and that these semiochemicals trigger a series of events when they reach the antennae of nurse bees. They may be transported by odorant binding proteins to specific receptors, which in turn may trigger signaling events and ultimately a neuronal/ behavioral response that could stop the disease cycle.  The integration of data from different methodologies  helps us increase our understanding of social immune mechanisms that have evolved in response to diseases.