In Australia, the European rabbit is one of the most damaging environmental and agricultural vertebrate pest species. The Rabbit haemorrhagic disease virus (RHDV) is a highly pathogenic hepatotropic virus that causes haemorrhages, liver failure and death within 72 h post infection. Since the mid-1990s, the virus is used as a key biocontrol agent, but due to the lack of a robust cell culture system, many aspects of the RHDV life cycle remained unknown, e.g., the entry receptor. Here, I used a recently established liver organoid cell culture system and crosslinking mass spectrometry to identify the RHDV entry receptor. Rabbit liver organoids were incubated with RHDV virus-like particles labelled with a heterobifunctional crosslinker. The cell-bound particles were exposed to UV light. Crosslinked virus-receptor complexes were then purified using a biotin group on the crosslinker and receptor candidates were identified using label-free quantification.
A list of the potential receptor candidates has been identified. The list includes liver-specific cell membrane proteins such as transporters, growth factor receptors and membrane proteins involved in endocytosis. Crosslinking mass spectrometry can be used as an efficient tool for virus receptor screening. Further validation of candidate receptors will be performed to confirm the specificity of binding and biological significance.