Human antisperm monoclonal antibodies constructed postvasectomy

Sperm and spermatogenic cell antigens, escaping the blood-testis/blood-epididymal barrier, elicit an autoimmune response in patients following vasectomy. In this study, antisperm antibody-positive sera and peripheral blood lymphocytes were obtained 6-9 mo following vasectomy. Serum antisperm antibody levels were assessed by enzyme-linked immunosorbent assay (ELISA) and indirect immunofluorescence. Lymphocyte-myeloma hybridomas were constructed by fusing peripheral blood lymphocytes, harvested from antisperm antibody-positive sera, with a hypox-anthine guanine-phosphoribosyltransferase (HGPRT)-negative mouse myeloma line. Immunoglobu-lin-secreting colonies surviving drug selection were detected by ELISA and screened for antisperm activity. Antispemi antibody-producing cultures were cloned and expanded for bulk antibody production both in culture and as ascites in athymic nude mice. Eight mouse-human fusions yielded 205 hybridomas secreting human monoclonal antibody, of which 11 demonstrated anti-sperm reactivity by ELISA. Two of these hybridomas are described in detail: HAS-i, which se-cretes human immunoglobulin M (1gM, kappa)-recognizing epitopes located on the sperm mid-piece, and HAS-2 (1gM, lambda), which secretes monoclonal antibody-recognizing epitopes located on the entire sperm tail. The results indicate successful capture of human antisperm autoantibody from the postvasectomy autoiminune state using somatic cell hybridization techniques