Woolly Monkey–HBV Infection in Squirrel Monkeys as a Surrogate Nonhuman Primate Model of HBV Infection

Abstract

Development of curative therapies for chronic hepatitis B virus (HBV) infection will likely require new animal models. Here, we evaluate HBV infection in squirrel monkeys based on the high‐sequence homology of the HBV receptor, Na+/taurocholate co‐transporting peptide (NTCP), between humans and squirrel monkeys. HBV PreS1 peptide was examined for binding human and squirrel monkey NTCP. Immunodeficient Fah−/−, NOD, Rag1−/−, Il2Rgnull (FNRG) mice engrafted with human or squirrel monkey hepatocytes were challenged with HBV or Woolly Monkey HBV (WMHBV). In addition, adult squirrel monkeys were inoculated with HBV, WMHBV, adeno‐associated virus containing an infectious genome of HBV (AAV‐HBV), and AAV‐WMHBV. Finally, neonate squirrel monkeys were assessed for the potential of chronic infection with WMHBV. PreS1 peptide efficiently bound to human and squirrel monkey NTCP but not to mouse or capuchin NTCP. FNRG mice engrafted with squirrel monkey hepatocytes were susceptible to infection by WMHBV but not human HBV. Similarly, adult squirrel monkeys could be infected with WMHBV but not human HBV, whereas chimeric mice engrafted with human hepatocytes were susceptible to HBV but not WMHBV. Infection of squirrel monkeys with AAV‐WMHBV yielded maximum viremia of 108 genomes/mL with detectable virus for up to 8 months. Notably, covalently closed circular DNA was detected in the liver of these animals. Infection of neonates with WMHBV led to detectable viremia for up to 6 months. Conclusions: Adult and neonate squirrel monkeys exhibited prolonged WMHBV viremia lasting 6‐8 months. This is greater than twice the duration of viremia achieved in other nonhuman primates and suggests that squirrel monkeys may be a suitable model for testing HBV therapeutics.

Innovative HBV Animal Models Based on the Entry Receptor NTCP

“…Indeed, in woolly monkeys (Lagothrix lagotricha), another hepadnavirus species, the woolly monkey HBV (WMHBV), was found, suggesting that other New World monkeys may also support hepadnavirus replication [58,70]. In support of this, Chen et al experimentally infected squirrel monkeys (Saimiri boliviensis boliviensis) with WMHBV, however, squirrel monkeys were not permissive to HBV, indicating other host limiting factors for different hepadnaviruses [71]. Recently, Souza et at.…”

“…Interestingly, New World monkeys including marmosets, woolly-, squirrel-, spider- or capuchin-monkeys do not possess the G158R mutation in NTCP and may be capable of supporting HBV infection [ 71 ]. Indeed, in woolly monkeys (Lagothrix lagotricha), another hepadnavirus species, the woolly monkey HBV (WMHBV), was found, suggesting that other New World monkeys may also support hepadnavirus replication [ 58 , 70 ].…”

Animal Models of Hepatitis B Virus Infection–Success, Challenges, and Future Directions

“…However, spider monkeys are also endangered [ 107 ] and, consequently, are not commonly available for HBV-related research. Interestingly, immunodeficient liver injury mice engrafted with primary hepatocytes from squirrel monkeys were selectively susceptible to WMHBV as opposed to HBV [ 64 ]. Nonetheless, this non-human primate model may prove promising; squirrel monkeys infected with WMHBV exhibited acute infections and, in some instances, chronic infections with the help of adeno-associated virus (AAV)-mediated delivery of WMHBV [ 64 ].…”

Liver humanized NSG-PiZ mice support the study of chronic hepatitis B virus infection and antiviral therapies

“…In these mouse models, PHH engraftment levels are sufficient to support high level replication of both laboratory and clinical HBV isolates 19,[23][24][25][26][27] , enabling their use in the study of antiviral therapies 25,[28][29][30][31][32] .…”