2018. al. (14). It is also known by other names, such as porcine enteric alphacoronavirus (PEAV) (13). For purposes of unity, SADS-CoV is the name used to refer to this new virus in the current study. The expanded host range of bat-origin HKU2 to pigs indicates that bats play an important role in the ecology and evolution of SADS-CoV, although the mechanism of bat-to-swine transmission remains unclear. In view of the damage caused by SARS and MERS for both animal and public health, 3-methoxy Tyramine HCl careful attention must be paid to the prevalence of CoV-associated disease among humans and domestic animals (15). Therefore, there is an urgent need for more information on the details of SADS-CoV infection. It is critically important to assess potential species barriers of SADS-CoV transmission since the animal hosts (other than pigs and bats) and zoonotic potential are still unknown. In the present study, we demonstrated that SADS-CoV possesses a very broad species tropism and is able to infect cell lines from diverse 3-methoxy Tyramine HCl species, including rodents and humans. Furthermore, evidence from experimental infection of mice with SADS-CoV identified splenic dendritic cells (DCs) as the major site of SADS-CoV replication in mice. Finally, we demonstrated that SADS-CoV does not utilize known CoV protein receptors 3-methoxy Tyramine HCl for cellular entry. These results present the possibility that 3-methoxy Tyramine HCl rodents are among the susceptible hosts of SADS-CoV, highlighting the potential cross-species transmissibility of SADS-CoV. RESULTS SADS-CoV can infect cell lines originating from various species. Previously, we reported that SADS-CoV was isolated in Vero cells supplemented with trypsin (11). Since exogenous trypsin is essential for propagation of PEDV isolates (16), likely by mediating activation of membrane fusion by S glycoprotein proteolysis (17), we were interested to know whether it is also required for SADS-CoV growth in cell culture. A total of 24 cell lines originating in various tissues of humans and different animal species were tested for susceptibility to SADS-CoV treated with or without trypsin (Table 1). As a brief summary of the results, 21 of the 24 cell lines showed significant susceptibility to SADS-CoV infection, defined 3-methoxy Tyramine HCl by efficient viral replication, antigen expression, and the appearance of cytopathic effect (CPE). The three cell lines that were not infected by SADS-CoV were MDCK, BFK, and RAW 264.7. TABLE 1 Summary of human and animal cell lines and their susceptibility to SADS-CoV infection as determined by CPE and IFA infection with SADS-CoVsplenocytes was monitored over 72 hpi by qRT-PCR targeting the SADS-CoV N gene. Next, SADS-CoV infection was quantified in the spleen using flow cytometry. We inoculated B6 wild-type mice with 5??105 TCID50 of virus either i.p. or p.o. and extracted the bulk immune cells from the spleen of infected animals at 3?dpi. The flow cytometry method was first validated in Vero cells infected with SADS-CoV at a multiplicity of infection (MOI) of 0.01, followed by staining with a pAb against the N or AC protein at 24 hpi (Fig. 4D). As the anti-AC pAb exhibited optimal intracellular staining for viral signals (Fig. 4D), it was used to determine the percentage of infected splenocytes. There were approximately 1.5- Ctsk and 2.5-fold increases of total splenocytes positive for virus replication after p.o. and i.p. inoculation, respectively (Fig. 4E, left; Fig. 4F), with a significant increase in the total number of AC-positive splenocytes in.