[Production and characterization of a monoclonal sperm immobilizing antibody to seminal plasma antigens]

Abstract

Rat spleen cells immunized to human azoospermic semen were fused with mouse myeloma cells (P3 X 63Ag8Ul) to obtain hybridomas which produce monoclonal sperm immobilizing antibodies. Of 114 hybrid clones obtained, 10 were found to produce antibodies with sperm immobilizing activity with complement. One clone (1C4) producing the highest antibody titer was chosen for further characterization. Chromosome analysis showed that 1C4 hybridoma cells contained two types of chromosomes which were derived from rat and mouse. Rat Ig was detected in both the cytoplasma and the culture medium of the cells by direct immunofluorescent test and immunodiffusion test, respectively. Gammaglobulin fractions from the culture medium had a strong sperm immobilizing activity and showed a common single precipitin line against human seminal plasma and human milk proteins. It was proved that the monoclonal antibody was produced to No. 7 antigen and not to No. 3 antigen (lactoferrin) in human seminal plasma, both of which have a common antigenicity to human milk proteins and compose the sperm coating antigens.