CD66 antigens are expressed on neutrophils and on several different epithelia, which are target tissues in gonococcal disease. Neisserial opacity (Opa) proteins, present in the bacterial outer membrane, have been shown to bind to CD66 antigens. Since Opa proteins are also implicated in the pathogenesis of gonorrhea, our goal is to understand the role of Opa-CD66 interactions in gonococcal disease