Porcine Reproductive and Respiratory Syndrome (PRRS) is the most economically important disease in swine in North America, Europe and Asia. PRRS is caused via infection of the pulmonary alveolar macrophages (PAMs) with the PRRS virus (PRRSV) causing respiratory illness and high fever in young growing pigs that predisposes them to secondary bacterial infections. PRRSV also causes severe reproductive failure in sows and boars. Although research is ongoing, PRRSV continues to elude a successful vaccine. In 2014, piglets were born with a gene edit in exon 7 of the Cluster of differentiation 163 (CD163) gene introduced by using the CRISPR/Cas9 site-directed nucleases system. The resulting litters of pigs were either challenged with multiple PRRSV isolates at 3 weeks of age or bred at maturity for a challenge with pregnant sows. The challenges demonstrated that the pigs were completely resistant to infectivity to both Type 1 and 2 isolates as measured by clinical signs, viremia, antibody response and lung histopathology. In a follow-up study, pregnant CD163-/- pigs were also challenged with PRRSV to determine if absence of CD163 in the dam should be sufficient to protect the CD163+/- fetuses that have functional CD163 protein. The wild-type sow and fetuses were actively infected with the PRRSV and one sow aborted. The CD163-/- sows carrying both the CD163-/- and CD163+/- fetuses were all negative for PRRSV nucleic acid and showed no sign of fetal or placental failure. The results of this study clearly demonstrate that the absence of CD163 in the sow is sufficient to protect a PRRSV-susceptible CD163+/- fetus. Gene editing of CD163 in pigs, via CRISPR/Cas9, successfully blocked PRRSV infectivity in young growing pigs and pregnant sows and their fetuses. This is a great example of the potential of utilizing gene editing to improve animal agriculture.

밤나방류에 대한 천적미생물을 중심으로 하는 신방제법의 개발을 목적으로 멸강나방에 강한 병원성을 갖는 바이러스의 선별시험을 실시하여 다음과 같은 결과를 얻었다. 멸강나방(Pseudaletia(=Leucania) separata, Walker)유충에 강한 병원성을 가진 핵다각체바이러스를 선별코자 21종(개통)의 NPV를 orchard grass의 양면에 발라서 멸강나방 2령 유충에 첨식한 결과 멸강나방 핵다각체병바이러스 4계통과 벼밤나방 핵다각체병바이러스가 병원성이 높았다. 멸강나방 핵다각체병바이러스 3계통(LsNPV-F, LsNPV-G 및 LsNPV-Y)를 공시해서, 다각체를 인공사료에 혼합하여 해서 멸강나방 1~6령의 유충에 대한 병원성 시험을 행한 결과 1~2령 유충에 대한 병원성이 높고, 4령 이후에는 낮아 약령기방제의 중요성을 시사했다.