Mask Tracy A, Schoenecker Kathryn A, Kane Albert J, Ransom Jason I, Bruemmer Jason E
Fort Collins Science Center, U.S. Geological Survey, Fort Collins, Colorado, USA; Animal Reproduction and Biotechnology Laboratory, Colorado State University, Fort Collins, Colorado, USA.
Fort Collins Science Center, U.S. Geological Survey, Fort Collins, Colorado, USA.
Theriogenology. 2015 Jul 15;84(2):261-7. doi: 10.1016/j.theriogenology.2015.03.012. Epub 2015 Mar 24.
Immunocontraception with porcine ZP (pZP) can be an effective means of fertility control in feral horses. Previous studies suggest that antibodies produced after pZP vaccination may both inhibit fertilization and cause follicular dysgenesis. Zonastat-H, PZP-22, and SpayVac are three pZP vaccines proposed for use in horses. Although all these vaccines contain the pZP antigen, variations in antigen preparation and vaccine formulation lead to differences in antigenic properties among them. Likewise, despite numerous efficacy and safety studies of Zonastat-H and PZP-22, the contraceptive mechanisms of SpayVac remain unclear. The preparation of pZP for SpayVac is thought to include more nonzona proteins, making it less pure than the other two vaccines. This may result in increased antigenicity of the vaccine. We therefore investigated the immunoreactivity of serum antibodies from SpayVac-vaccinated mares to equine zona protein. Western blot analyses revealed an immunoreactivity of these antibodies to protein isolated from mature equine oocytes, ZP, follicular tissues, and ovarian tissues. Immunohistochemical analyses were used to locate the binding of serum antibodies to the ZP of immature oocytes in ovarian stromal tissue. We also found serum antibodies from SpayVac-treated mares to be predominantly specific for zona protein 3. Collectively, our results suggest a model where serum antibodies produced in response to SpayVac vaccination are immunoreactive to equine zona protein in vitro. Our study lends insight into the contraceptive mechanisms underlying the infertility observed after SpayVac vaccination.
使用猪源透明带（pZP）进行免疫避孕可能是控制野马繁殖力的一种有效手段。先前的研究表明，pZP疫苗接种后产生的抗体可能既抑制受精又导致卵泡发育异常。Zonastat-H、PZP-22和SpayVac是三种提议用于马匹的pZP疫苗。尽管所有这些疫苗都含有pZP抗原，但抗原制备和疫苗配方的差异导致它们之间抗原特性的不同。同样，尽管对Zonastat-H和PZP-22进行了大量的有效性和安全性研究，但SpayVac的避孕机制仍不清楚。据认为，SpayVac的pZP制备中包含更多的非透明带蛋白，使其纯度低于其他两种疫苗。这可能导致疫苗的抗原性增加。因此，我们研究了接种SpayVac的母马血清抗体对马透明带蛋白的免疫反应性。蛋白质印迹分析显示，这些抗体对从成熟马卵母细胞、透明带、卵泡组织和卵巢组织中分离出的蛋白质具有免疫反应性。免疫组织化学分析用于定位血清抗体与卵巢基质组织中未成熟卵母细胞透明带的结合。我们还发现，SpayVac处理的母马血清抗体主要对透明带蛋白3具有特异性。总体而言，我们的结果提示了一个模型，即接种SpayVac疫苗后产生的血清抗体在体外对马透明带蛋白具有免疫反应性。我们的研究为深入了解SpayVac疫苗接种后观察到的不育背后的避孕机制提供了线索。
