Western blotting and immunohistochemistry were performed in order to define the tissue distribution of the S19 epitope, which has been proposed as a target for immunocontraception.
The results support the use of the S19 epitope as a contraceptive immunogen and the suitability of the S19 mAb as an intravaginal contraceptive. The study determined that the S19 epitope is specific to tissues of the male reproductive tract, namely the epididymis and vas deferens, and it is absent from the human female reproductive tract and all somatic tissues tested to date. The findings support the view that S19 will be safe for use in the human female reproductive tract. The successful agglutination of spermatozoa with a formulation of the S19 native mAb conjugated to the Ovasome trilamellar liposome delivery vehicle demonstrated that the antibody could efficiently agglutinate spermatozoa in such a formulation. There was a clear demonstration of the maintenance of antibody activity when conjugated with a clinically proven delivery vehicle. It has been suggested that a reversible contraceptive vaccine would be the most effective solution to meet the multifaceted needs of today's society. In order to be an effective vaccine candidate, such an antigen should be tissue specific, involved in fertility, and able to raise a high antibody titer. The description of materials and methods addresses monoclonal antibodies, immunohistochemistry, FACS analysis, protein extract preparation, electrophoresis and immunoblot analysis, immunofluorescence microscopy, and sperm agglutination assay. 7 figures and 40 references