Problems With Understanding Chlamydia trachomatis Immunology.

The payoff for understanding Chlamydia trachomatis immunology is the development of a vaccine. Two lines of research have contributed to our current understanding of C. trachomatis immunology. The first is the Grayston model of type-specific immunity and genus-specific pathology, which was elaborated by Caldwell and Morrison as the major outer membrane protein and heat shock protein 60 paradigm. The second is the murine model of Chlamydia muridarum infection, which established the essential role of major histocompatibility complex class II and CD4 T cells in immunity. However, neither approach has yielded a vaccine. I review these 2 lines of research and conclude with 6 problem areas in human C. trachomatis immunology whose resolution may result in a vaccine.