Sperm-mediated host-derived DNA transfer as a new mechanism for immune system evasion of sexually transmitted genital tract pathogens.

Over one century of extensive efforts directed towards investigating the immune response and the immuno-protection associated with sexually transmitted infections have failed to produce any effective vaccines against most of the major pathogens, among them Neisseria gonorrhea, herpes simplex virus type 2, and Chlamydia trachomatis. Attempts to design and develop protective vaccines against them have also yielded disappointing results. It has long been felt that there might be another yet undiscovered complicating factor, in addition to the recognized difficulties, which might be impeding the development of successful vaccines. Unlike the other body organs and systems, the genital tract and the elements found within it (e.g., spermatozoa) are endowed with unique features, some of which are associated with inherent DNA transferability skills as physiologically required from such an environment. We hypothesize that there is a novel evasion mechanism that involves an unusual sperm-mediated host-derived DNA transfer by which sexually transmitted genital tract microorganisms can express brand new chimeric antigens and epitopes and, by doing so, thus evade the surveillance of the immune system. This hypothesis may describe what would be the long-awaited breakthrough in the search for a vaccine against sexually transmitted infections. It may also assist in developing better-designed vaccines in general, and may have implications on other microorganism-related challenges (e.g., antibiotic resistance).