*2.3. Animals*

Female BALB/c mice, six to eight-week-old (average weight, 16.0 ± 2.0 g), were obtained from Beijing Vital River Laboratory Animal Technology Co., Ltd. (Beijing, China). The mice were quarantined 2–3 days prior to the experimental manipulation and were fed standard rodent chow and had ad libitum access to water. Animal experiments were conducted under the guidance of both the Guangdong Provincial Center for Disease Control and Prevention's Institutional Animal Care and Use Committee. The protocols were approved by South China Agricultural University' committee on the Ethics of Animal Experiments of Animal Biosafety Level 3 (permit no. 2017A002).
