Norton E J, Diekman A B, Westbrook V A, Mullins D W, Klotz K L, Gilmer L L, Thomas T S, Wright D C, Brisker J, Engelhard V H, Flickinger C J, Herr J C
Department of Cell Biology, Center for Recombinant Gamete Contraceptive Vaccinogens, University of Virginia Health System, Charlottesville, VA 22908, USA.
Tissue Antigens. 2002 Nov;60(5):354-64. doi: 10.1034/j.1399-0039.2002.600502.x.
The identification of unique sperm surface epitopes that are not expressed or exposed in the female reproductive tract is a key element in the development of antibody-based contraceptives. Western blotting and immunohistochemistry were performed to define the tissue distribution of the S19 epitope, which has been proposed as a target for immunocontraception. S19 is an IgG1 murine monoclonal antibody (mAb) directed to an N-linked carbohydrate epitope on a 15-25 kDa glycoprotein, sperm agglutination antigen-1 (SAGA-1), containing a peptide core identical to that of the lymphocytic surface protein CD52. In this study, the S19 epitope was shown to be absent from human lymphocytes, demonstrating a distinction between this epitope and the CAMPATH epitope that is recognized by an antibody against the terminal tripeptide and GPI-anchor of CD52. Further tissue specificity analysis identified the S19 epitope in the epithelium of the human epididymis and vas deferens, as well as on both epididymal and ejaculated spermatozoa. In contrast, the S19 epitope was absent in the five human female reproductive tract and 18 other somatic tissues tested. These results support the use of the S19 epitope as a contraceptive immunogen and the suitability of the S19 mAb as an intravaginal contraceptive. To test the agglutinating activity of the S19 mAb in a formulation designed for vaginal use, S19 mAb were bound to the surface of Novasomes, a multilamellar liposome delivery vehicle. S19-Novasome formulations agglutinated human spermatozoa and were as effective as unbound S19 mAb, demonstrating the feasibility of spermistatic contraceptives targeted to the male reproductive tract specific carbohydrate epitope.
鉴定在女性生殖道中未表达或未暴露的独特精子表面表位是基于抗体的避孕药开发的关键要素。进行了蛋白质印迹法和免疫组织化学以确定S19表位的组织分布，S19表位已被提议作为免疫避孕的靶点。S19是一种IgG1小鼠单克隆抗体（mAb），针对15 - 25 kDa糖蛋白精子凝集抗原-1（SAGA-1）上的N-连接碳水化合物表位，其包含与淋巴细胞表面蛋白CD52相同的肽核心。在本研究中，显示人淋巴细胞中不存在S19表位，这表明该表位与抗CD52末端三肽和糖基磷脂酰肌醇锚定的抗体所识别的CAMPATH表位之间存在区别。进一步的组织特异性分析在人附睾和输精管的上皮以及附睾精子和射出精子上均鉴定出S19表位。相比之下，在所测试的五种人类女性生殖道和其他18种体细胞组织中不存在S19表位。这些结果支持将S19表位用作避孕免疫原以及S19单克隆抗体用作阴道内避孕药的适用性。为了在设计用于阴道使用的制剂中测试S19单克隆抗体的凝集活性，将S19单克隆抗体结合到多层脂质体递送载体诺华体（Novasomes）的表面。S19 - 诺华体制剂凝集人精子，并且与未结合的S19单克隆抗体一样有效，证明了靶向男性生殖道特异性碳水化合物表位的杀精避孕药的可行性。
