In Vitro detection of Chronic Wasting Disease (CWD) prions in semen and reproductive tissues of white tailed deer bucks (Odocoileus virginianus)

Chronic Wasting Disease (CWD) is a prion disease affecting several cervid species. Among them, white-tailed deer (WTD) are of relevance due to their value in farming and game hunting. The exact events involved in CWD transmission in captive and wild animals are still unclear. An unexplored mechanism of CWD spread involves transmissions through germplasm, such as semen. Surprisingly, the presence and load of CWD prions in semen and male sexual tissues from WTD has not been explored. Here, we described the detection of CWD prions in semen and sexual tissues of WTD bucks utilizing the Protein Misfolding Cyclic Amplification (PMCA) technology. Samples were obtained post-mortem from farmed pre-clinical, CWD positive WTD bucks possessing polymorphisms at position 96 of the PRNP gene. Our results show that overall CWD detection in these samples had a sensitivity of 59.3%, with a specificity of 97.2%. The data indicate that the presence of CWD prions in male sexual organs and fluids is prevalent in late stage, pre-clinical, CWD-infected WTD (80%-100% of the animals depending on the sample type analyzed). Our findings reveal the presence of CWD prions in semen and sexual tissues of prion infected WTD bucks. Future studies will be necessary to determine whether sexual contact and/or artificial inseminations are plausible means of CWD transmission in susceptible animal species.慢性消耗病（Chronic Wasting Disease, CWD）是一类侵染多种鹿科物种的朊病毒疾病。其中，白尾鹿（white-tailed deer, WTD）因其在养殖与狩猎产业中的经济价值而受到广泛关注。目前，圈养与野生动物中CWD传播的确切过程仍未明确。一种尚未被探索的CWD传播机制涉及通过生殖质（如精液）实现的传播。令人意外的是，目前尚无针对白尾鹿精液及雄性生殖组织中CWD朊病毒的存在情况与载量的相关研究。本研究利用蛋白质错误折叠循环扩增（Protein Misfolding Cyclic Amplification, PMCA）技术，在白尾鹿雄鹿的精液与生殖组织中成功检测到CWD朊病毒。实验样本取自经尸检的养殖型临床前期CWD阳性白尾鹿雄鹿，这些个体的PRNP基因第96位存在基因多态性。研究结果显示，本次针对上述样本的CWD检测总体灵敏度为59.3%，特异性为97.2%。数据表明，在临床前期的晚期感染CWD的白尾鹿中，雄性生殖器官及体液内的CWD朊病毒检出率较高（依所分析的样本类型不同，检出率区间为80%~100%）。本研究证实，感染朊病毒的白尾鹿雄鹿的精液与生殖组织中存在CWD朊病毒。未来需开展进一步研究，以明确性接触及/或人工授精是否为易感动物物种间CWD传播的可行途径。