the present invention relates to antigenic proteins from chlamydia trachomatis . a method for inducing an immune response with an immunogenic chlamydia protein is provided in which an effective amount of an immunogenic chlamydia protein is administered to a subject . in one example , the immunogenic chlamydia protein has a molecular weight of about 15 . 8 kda and a pi of about 4 . 8 . in another example , the immunogenic chlamydia protein has an n - terminal amino acid sequence of ttesletlve . in another example , the immunogenic chlamydia protein is chlamydia ribosomal protein l7 / l12 or a serovar homologue of chlamydia ribosomal protein l7 / l12 .