The mechanisms by which the male genital tract protects itself from sexually transmitted diseases by largely unknown. Based upon evidence in other organ systems, it is likely that mucins in the male reproductive tract interact with pathogens in a complex manner which includes barrier function, specific binding, complexes with secretory IgA and proteases and possibly direct growth inhibition by the glycoprotein itself. Preliminary data has shown that semen contains significant amounts if mucin which are present in the cells of the urethral glands, seminal vesicles and prostate. In this project, we will determine the specific mucin genes being expressed in the male genital tract, their distribution, and develop systems in which to these mucins alone and in combination with other components of the immune system before, during and after STD infection.