ARTICLES https://doi.org/10.1038/s41559-021-01407-1 ACE2 receptor usage reveals variation in susceptibility to SARS-CoV and SARS-CoV-2 infection among bat species Huan Yan 1,5, Hengwu Jiao 2,5, Qianyun Liu1, Zhen Zhang1, Qing Xiong1, Bing-Jun Wang2, Xin Wang1, Ming Guo1, Lin-Fa Wang 3, Ke Lan 1,4 ✉ , Yu Chen 1 ✉ and Huabin Zhao 1,2 ✉ Bats are the suggested natural hosts for severe acute respiratory syndrome coronavirus (SARS-CoV) and the causal agent of the coronavirus disease 2019 (COVID-19) pandemic, SARS-CoV-2. The interaction of viral spike proteins with their host receptor angiotensin-converting enzyme 2 (ACE2) is a critical determinant of potential hosts and cross-species transmission. Here we use virus–host receptor binding and infection assays to examine 46 ACE2 orthologues from phylogenetically diverse bat spe- cies, including those in close and distant contact with humans. We found that 24, 21 and 16 of them failed to support infection by SARS-CoV, SARS-CoV-2 or both viruses, respectively. Furthermore, we confirmed that infection assays in human cells were consistent with those in two bat cell lines. Additionally, we used genetic and functional analyses to identify critical residues in bat ACE2 receptors associated with viral entry restrictions. Our results suggest that many bat species may not be the potential hosts of one or both viruses and that no correlation was identified between proximity to humans and probability of being natural hosts of SARS-CoV or SARS-CoV-2. This study demonstrates dramatic variation in susceptibility to SARS-CoV and SARS-CoV-2 infection among bat species and adds knowledge towards a better understanding of coronavirus–bat interaction. he unprecedented pandemic of coronavirus disease 2019 two viruses, these results provide important insights into pandemic (COVID-19), caused by the new coronavirus SARS-CoV-2, control and wildlife conservation. Thas led to major threats to public health and economic development. It is therefore critically important to identify natural Results or intermediate hosts of SARS-CoV-2 to prevent further spread Evolution of ACE2 in bats inhabiting urban or rural areas. of COVID-19 and future emergence of similar diseases. Inferred We collected ACE2 orthologues from 46 bat species across the from sequence similarity of human and bat virus genomes, it was phylogeny (Fig. 1 and Supplementary Table 1). These species suggested that horseshoe bats (Rhinolophus spp.) might be natu- contained 28 species that roost or forage in urban areas near ral hosts of SARS-CoV and SARS-CoV-2 (refs. 1–3). These sugges- humans and 18 species more restricted to rural areas and hence tions have resulted in misguided fears and unwarranted attacks on likely to have minimal contact with humans (Supplementary many bats—including species other than Rhinolophus—thereby Table 2). In total, we examined 46 species representing 11 bat seriously impacting efforts towards bat conservation4. Given the families (Supplementary Table 3). After aligning the protein remarkable diversity of bats, which includes more than 1,400 spe- sequences of bat ACE2 orthologues, we examined 25 critical res- cies across the globe5, assessing the possibility that diverse bat idues involved in the binding of the surface spike glycoprotein species act as potential hosts of SARS-CoV and SARS-CoV-2 is (S protein) of SARS-CoV-2 (ref. 9) (Extended Data Fig. 1). Genetic urgent and crucial for both controlling outbreaks and protecting variations were observed in nearly all these 25 sites, which may populations of wildlife. have led to different abilities to support entry of SARS-CoV Angiotensin-converting enzyme 2 (ACE2) is the main host cell and SARS-CoV-2 (ref. 9). Furthermore, we detected at least 22 receptor of SARS-CoV and SARS-CoV-2 and plays a vital role in amino acid sites that are putatively under positive selection mediating viral entry to cause infection1,6. The interaction of a virus (Supplementary Table 4), which is indicative of heterogeneous with its host receptor has been repeatedly demonstrated to serve selection pressure across sites. Notably, four of these positively as a primary determinant of host range7,8. In this study, we tested selected sites are in the binding region of ACE2 to the SARS-CoV-2 ACE2 orthologues from 46 bat species across the phylogeny, includ- S protein (Supplementary Table 4). ing species occurring in urban and in rural areas, for their ability to support the entry of SARS-CoV and SARS-CoV-2 using virus–host Interaction between bat ACE2 orthologues and SARS-CoV or receptor binding and infection assays. Hence, this study assessed SARS-CoV-2 receptor binding domain. Efficient binding between whether diverse bat species are potential hosts of SARS-CoV or the S protein and the ACE2 receptor is essential for SARS-CoV and SARS-CoV-2. Moreover, by determining the correlation between SARS-CoV-2 entry. This binding is mainly mediated by the interac- proximity to humans and probability of being natural hosts of the tion between the critical residues on the receptor-binding domain 1State Key Laboratory of Virology, Modern Virology Research Center, College of Life Sciences, Wuhan University, Wuhan, China. 2Department of Ecology, Tibetan Centre for Ecology and Conservation at WHU-TU, Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, China. 3Duke-NUS Medical School, Singapore, Singapore. 4Frontier Science Center for Immunology and Metabolism, Wuhan University, Wuhan, China. 5These authors contributed equally: Huan Yan, Hengwu Jiao. ✉e-mail: [email protected]; [email protected]; [email protected] 600 NATURE ECOLOgy & EVOLUTION | VOL 5 | MAY 2021 | 600–608 | www.nature.com/natecolevol NATURE ECOLOGY & EVOLUTION ARTICLES No entry for SARS ++ Strong support *** High expression In close contact No entry for SARS2 + Weak support ** Medium expression In distant contact No entry for both – No support * Low expression Bat–human Label Expression SARS SARS2 contact Rousettus aegyptiacus Bat01 * ++ ++ Eonycteris spelaea Bat05 ** + + Pteropus alecto Bat02 * ++ + Pteropus giganteus Bat03 ++ ++ * Pteropodidae + Eidolon helvum Bat04 * + (Old World Macroglossus sobrinus Bat06 + + fruit bats) ** Yinpterochiroptera Cynopterus sphinx Bat07 ** ++ – Cynopterus brachyotis Bat08 ** ++ – Rhinolophus ferrumequinum Bat09 ** – – Rhinolophidae Rhinolophus sinicus Bat10 ++ *** – (horseshoe bats) Rhinolophus pearsonii Bat11 *** – – Hipposideros armiger Bat12 ** – – Hipposideros pratti Bat14 ** – – Hipposideridae Hipposideros galeritus Bat13 *** – – Megadermatidae (Bats) Megaderma lyra Bat15 *** ++ ++ Taphozous melanopogon Bat17 ** – ++ Emballonuridae Noctilio leporinus Bat16 ** + + Noctilionidae Anoura caudifer Bat18 ** – + Carollia perspicillata Bat23 ** – ++ Sturnira hondurensis Bat25 ** – + Artibeus jamaicensis Bat26 ** + + Trachops cirrhosus Bat19 ** ++ + Phyllostomidae Tonatia saurophila Bat21 ** – – (New World leaf-nosed bats) Phyllostomus discolor Bat22 ** + – Vampyrum spectrum Bat20 ** + – Desmodus rotundus Bat27 ** – + Micronycteris hirsuta Bat24 ** – ++ Pteronotus parnellii Bat28 – – ** Yangochiroptera Pteronotus davyi Bat30 * – – Mormoopidae Mormoops blainvillei Bat29 *** – + Tadarida brasiliensis Bat31 ++ ++ ** Molossidae Molossus molossus Bat32 *** – – Miniopterus schreibersii Bat33 ++ ++ ** Miniopteridae Miniopterus natalensis Bat34 ** – – Eptesicus fuscus Bat35 * – – Nycticeius humeralis Bat41 ** – – Pipistrellus pipistrellus Bat37 * – ++ Pipistrellus kuhlii Bat39 ** – – Lasiurus borealis Bat38 ** – – Aeorestes cinereus Bat36 – – ** Vespertilionidae Antrozous pallidus Bat40 *** ++ ++ (vesper bats) Murina aurata Bat42 * – – Myotis myotis Bat43 * + + Myotis davidii Bat44 * ++ + Myotis brandtii Bat45 ** + + Myotis lucifugus Bat46 ** + + Homo sapiens Human ** ++ ++ Outgroup Fig. 1 | Phylogenetic tree of 46 bat species in this study. The labels of bat species in our experiments are indicated. Expression levels determined by western blot (Fig. 2a) are shown with asterisk symbols compared with human ACE2: the triple asterisk indicates high expression, the double asterisk indicates medium expression and the single asterisk indicates low but detectable expression. The ability of bat ACE2 to support SARS-CoV and SARS-CoV-2 pseudovirus entry is shown with different signs (Fig. 3a,b): infection data are presented as percentage mean values of bat ACE2 supporting infection compared with the infection supported by human ACE2. Infection efficiency <5% is indicated with a minus sign, between 5 and 50% with a plus sign and >50% with a double plus sign. Bat phylogeny was taken from previous studies28–30. (RBD) and ACE2. To characterize the receptor function of ACE2 ACE2 orthologues through lentiviral transduction of 293T cells orthologues in a range of diverse bat species, we generated a stable lacking ACE2 expression10. All bat ACE2 orthologues were exog- cell library consisting of cell lines expressing the respective 46 bat enously expressed at a comparable level after puromycin selection, NATURE ECOLOgy & EVOLUTION | VOL 5 | MAY 2021 | 600–608 | www.nature.com/natecolevol 601 ARTICLES NATURE ECOLOGY & EVOLUTION a Human Human Human Human Human Bat10 Bat11 Bat12 Bat13 Bat14 Bat15 Bat16 Bat17 Bat18 Bat19 Bat20 Bat21 Bat22 Bat23 Bat24 Bat25 Bat26 Bat27 Bat28 Bat29 Bat30 Bat31 Bat32 Bat33 Bat34 Bat35 Bat36 Bat37 Bat38 Bat39 Bat40 Bat41 Bat42 Bat43 Bat44 Bat45 Bat46 Mock Mock Mock Mock Mock Bat1 Bat2 Bat3 Bat4 Bat5 Bat6 Bat7 Bat8 Bat9 ACE2 (anti- FLAG-tag) GAPDH b ACE2 expression (anti-FLAG-tag)