Molecular characterization of RIG-I, STAT-1 and IFN-beta in the horseshoe bat

• The genes of RIG-I, STAT-1 and IFN-β in Chinese horseshoe bats were sequenced and analyzed.
• The expression patterns of RIG-I, STAT-1 and IFN-β were appraised in bat tissues.
• The virus induced IFN-β expression is higher in bat cells than in mouse cells.
• The replication of invaded VSV is more in mouse cells than in bat cells.

Wild Chinese horseshoe bats have been proven to be natural reservoirs of SARS-like coronaviruses. However, the molecular characterization of key proteins in bats still needs to be explored further. In this study, we used cloning and bioinformatics to analyze the sequence of RIG-I, STAT-1 and IFN-β in the immortalized cell lines from Rhinolophus affinis and Rhinolophus sinicus. Then, we treated different bat cells, mouse embryonic fibroblasts (MEF) and splenocytes with polyinosinic–polycytidylic acid (polyI:C) and vesicular stomatitis virus (VSV) to assess and compare antiviral immune responses between bats and mice. Our results demonstrated that bat RIG-I, STAT-1 and IFN-β showed close homology with human, mouse, pig and rhesus monkey. RIG-I and STAT-1 were both highly expressed in bat spleen. Furthermore, IFN-β was induced by polyI:C and VSV in both bat and mouse cells. These findings have provided new insight into the potential characteristics of the bat innate immune system against viral infection.