Expression in E. coli of Chlamydia trachomatis antigen recognized during human infection

Abstract

Chlamydia trachomatis, a prokaryotic obligate intracellular parasite of eukaryotic cells, has long been recognized as the agent of trachoma, the major infectious cause of human blindness¹. In the past decade, clinical investigations have shown that the frequency and severity of chlamydial genital infection parallels that of gonorrhoea, and that C. trachomatis is a major cause of non-gonococcal urethritis, epidymitis, proctitis, cervicitis and salpingitis, as well as conjunctivitis and pneumonia in neonates². Despite the new awareness of its role in human disease, there is a need for improved methods of identification and control of C. trachomatis infections. Progress in these areas awaits a more detailed understanding of the pathogenesis of chlamydial infection, including definition of key antigenic structures recognized in human disease. We have studied the immune response to chlamydial polypeptides during human infection and have found that most infected patients have antibody to polypeptides of molecular weight (M_r) 67,000 (67K), 60K, 40K, 19K and 16K, regardless of infecting immunotype³. We report here the cloning and expression in Escherichia coli of the 19K C. trachomatis polypeptide, an immunogen in human chlamydial infection.