Hepatitis B virus (HBV) poses a significant global health challenge, necessitating the urgent development of curative therapeutics. However, this progress is impeded by the lack of robust, immunocompetent preclinical animal models due to HBV’s strict species specificity. We previously showed that vector-mediated expression of the HBV entry receptor, human sodium-taurocholate cotransporting polypeptide (hNTCP), renders macaques fully susceptible to HBV infection. In this study, we have generated transgenic macaques expressing hNTCP, marking the creation of the first transgenic nonhuman primate model for infectious disease research. We used PiggyBac (PB) transposon technology to insert a liver-specific hNTCP expression cassette into rhesus macaque zygotes and transferred the resulting embryos into surrogate females, resulting in two healthy transgenic offspring. In both animals, hNTCP is highly and selectively expressed in the liver. Most importantly, we show that isolated hepatocytes from these monkeys are susceptible to HBV infection. These findings lay the foundation for the development of a nonhuman primate HBV model, facilitating the advancement and validation of curative HBV therapies.

Obtaining quality oocytes is a prerequisite for ART-based studies. Here we describe a method for transabdominal ultrasound-guided (US) oocyte retrieval in rhesus macaques (Macaca mullata) and compare it to the standard surgical approach using laparoscopy (LAP). We analyzed oocyte yield from six continuous reproductive seasons (2017–2023) that included n = 177 US-guided and n = 136 laparoscopic oocyte retrievals. While the ultrasound-guided technique retrieved significantly fewer oocytes on average (LAP: 40 ± 2 vs. US: 27 ± 1), there was no difference in the number of mature metaphase II oocytes (MII) between the two techniques (LAP: 17 ± 1 vs. US: 15 ± 1). We show that oocytes retrieved by the ultrasound-guided approach fertilize at the same rates as those obtained via the laparoscopic procedure (LAP Fert Rate: 84% ± 2% vs. US Fert Rate: 83% ± 2%). In conclusion, minimally invasive ultrasound-guided oocyte retrieval improves animal welfare while delivering equivalent numbers of mature oocytes, which are ideal for ART. Furthermore, we show that oocyte competency, as represented by fertilization rate, is not affected by retrieval technique. Therefore, the Oregon National Primate Research Center (ONPRC) has adopted the ultrasound-guided approach as the standard technique for oocyte retrieval.