Identification of immunogenic determinants of the spike protein of SARS-like coronavirus

Bat SARS-like coronavirus (SL-CoV) has a genome organization almost identical to that of SARS-CoV, but the N-terminus of the Spike (S) proteins, which interacts with host receptor and is a major target of neutralizing antibodies against CoVs, of the two viruses has only 63–64% sequence identity. Although there have been reports studying the overall immunogenicity of S(SL), knowledge on the precise location of immunodominant determinants for S(SL) is still lacking. In this study, using a series of truncated expressed S(SL) fragments and S(SL) specific mouse sera, we identified two immunogenic determinants for S(SL). Importantly, one of the two regions seems to be located in a region not shared by known immunogenic determinants of the S(SARS). This finding will be of potential use in future monitoring of SL-CoV infection in bats and spillover animals and in development of more effective vaccine to cover broad protection against this new group of coronaviruses.