[Preparation and identification of monoclonal antibodies against Chlamydia trachomatis Tarp protein].

To obtain monoclonal antibodies (mAbs) against Chlamydia trachomatis Tarp protein. Chlamydia trachomatis serovar D recombinant Tarp fusion protein was cloned and expressed. Balb/c mice were immunized with recombinant Tarp fusion protein, and the spleen cells of the immunized mice were fused with SP2/0 mouse myeloma cells. The hybridoma cell lines secreting mAbs against Tarp protein were screened by an indirect immunofluorescence assay and subcloned by limiting dilution culture. The specificities of these mAbs to Tarp were determined by ELISA, and their isotype and chlamydial species specificity identified by an indirect immunofluorescence assay. Recombinant GST-Tarp fusion protein with a relative molecular mass of about 136 000 was successfully cloned and expressed. Seven hybridoma cell lines stably secreting specific mAbs against Tarp protein were obtained. All the 7 mAbs reacted strongly with Tarp protein but not with other chlamydial proteins. Two mAbs were identified to belong to IgG2a isotype and the other 5 to IgG1 isotype. All the 7 mAbs reacted strongly with chlamydia serovar A, D, and L2, but not with MoPn, 6BC, or AR39. The highly specific mAbs against Tarp protein have been obtained to facilitate further study of the structure and function of Chlamydia Tarp protein.