https://link.springer.com/article/10.1007/s00705-010-0729-6

The discovery of SARS-like coronavirus in bats suggests that bats could be the natural reservoir of SARS-CoV. However, previous studies indicated the angiotensin-converting enzyme 2 (ACE2) protein, a known SARS-CoV receptor, from a horseshoe bat was unable to act as a functional receptor for SARS-CoV. Here, we extended our previous study to ACE2 molecules from seven additional bat species and tested their interactions with human SARS-CoV spike protein using both HIV-based pseudotype and live SARS-CoV infection assays. The results show that ACE2s of Myotis daubentoni and Rhinolophus sinicus support viral entry mediated by the SARS-CoV S protein, albeit with different efficiency in comparison to that of the human ACE2. Further, the alteration of several key residues either decreased or enhanced bat ACE2 receptor efficiency, as predicted from a structural modeling study of the different bat ACE2 molecules. These data suggest that M. daubentoni and R. sinicus are likely to be susceptible to SARS-CoV and may be candidates as the natural host of the SARS-CoV progenitor viruses. Furthermore, our current study also demonstrates that the genetic diversity of ACE2 among bats is greater than that observed among known SARS-CoV susceptible mammals, highlighting the possibility that there are many more uncharacterized bat species that can act as a reservoir of SARS-CoV or its progenitor viruses. This calls for continuation and expansion of field surveillance studies among different bat populations to eventually identify the true natural reservoir of SARS-CoV.

Wikipedia: Pseudotyping is the process of producing viruses or viral vectors in combination with foreign viral envelope proteins. The result is a pseudotyped virus particle.[1] With this method, the foreign viral envelope proteins can be used to alter host tropism or an increased/decreased stability of the virus particles. Pseudotyped particles do not carry the genetic material to produce additional viral envelope proteins, so the phenotypic changes cannot be passed on to progeny viral particles.

For example, pseudotyping allows one to specify the character of the envelope proteins. A frequently used protein is the glycoprotein G of the Vesicular stomatitis virus (VSV), short VSV-G. These envelope proteins transduce to all cell types.

Viral pseudotyping can also be very useful for studying emerging and highly pathogenic viruses. These viruses are often difficult for researchers to study because of the danger they pose. Pseudotypes can be made where the HIV envelope glycoprotein or the rhabdovirus envelope glycoprotein are replaced with the envelope from a highly pathogenic virus. These pseudotypes allow scientists to characterize the cellular tropism and entry determinants of otherwise challenging to study viruses.