Isolation of a sperm autoantigen from the kidneys of vasectomized rabbits

The rabbit sperm membrane autoantigen, RSA-1, has been isolated from the kidneys of bilaterally vasectomized rabbits. Using detergent extraction the IgG-RSA-1 complex in the kidney was isolated first on an anti-IgG immunocolumn. The eluted IgG-RSA-1 complex was then applied to an anti-sperm autoantibody column which bound the RSA-1, displacing the kidney anti-RSA-1 IgG. RSA-1 was subsequently eluted from the anti-sperm autoantibody column. This is the first identification of a known sperm antigen in the kidneys of vasectomized animals. Furthermore, this methodology should be applicable to the isolation of antigens from a variety of other tissues and immune complexes.