Anti-Momp monoclonal antibody, clone HT10 (8/2010)

The Chlamydia trachomatis major outer membrane protein (MOMP) is the quantitatively predominant surface protein which has important functional, structural and antigenic properties. We have cloned and overexpressed the MOMP in Escherichia coli. The MOMP is surface exposed in C. trachomatis and capable of eliciting protective antibodies in infected hosts, and therefore has potential as a candidate vaccine to prevent infection with this significant human pathogen. The recombinant MOMP clone, L2rMOMP, contained the entire MOMP gene including the encoded leader sequence. Large quantities of chlamydial MOMP were expressed, some of which was processed and translocated to the E. coli surface. Surface localization of the MOMP was demonstrated by the binding of anti-MOMP monoclonal antibodies to the surface of the induced clone, and was visualized by fluorescence and electron microscopy. The induction of MOMP expression had a rapidly lethal effect on the L2rMOMP E. coli clone. Although no genetic system exists for Chlamydia, development of a stable, inducible E. coli clone which overexpresses the chlamydial MOMP permits a study of the biological properties of the MOMP, including the contribution of the MOMP variable segments to the topographical interactions which determine the antigenic structure responsible for human immune response.

Background SLE is an autoimmune condition affecting predominantly women. Little is known regarding Chlamydia trachomatis infection in women with SLE, which may drive autoimmunity and contribute to obstetrical and vascular complications. Methods This single-centre, case-control study set primary endpoint in the comparative seropositivity rate to C. trachomatis major outer membrane protein (MOMP) and chlamydial heat-shock protein-60 (cHSP60) in age-matched subjects. The secondary endpoints were obstetrical outcomes, cardiovascular events and results from screening procedures for cervical cancer. Results Eighty-four women with SLE and 50 age-matched controls were included. Seropositivity to C. trachomatis did not differ significantly between groups (10% of cases positive for anti-MOMP vs 12% of controls; 43% of cases positive for anti-cHSP60 vs 32% of controls). Women with SLE were more often of non-Caucasian ethnicity and had lower educational level. They relied less frequently on oral contraception and resorted more frequently to elective pregnancy termination. Pre-eclampsia and ectopic pregnancy occurred only in SLE. Women with SLE also experienced more cardiovascular events. In SLE, antibodies to cHSP60 were associated with a history of pericarditis and abnormal screening tests for cervical cancer. Antibody titres to C. trachomatis were not associated with disease activity or SLE treatment, nor were there associations with other gynaecological, obstetrical or vascular outcomes. Conclusion Prevalence of antibodies to C. trachomatis was not increased in women with SLE. No significant association was found between these antibodies and obstetrical or cardiovascular complications.