Tag Archives: Chlamydia trachomatis MOMP

New monoclonal antibodies to the Chlamydia trachomatis main outer membrane protein and their immunobiological properties

O. Yu. Galkin1,2, O. B. Besarab1, Yu. V. Gorshunov1, O. M. Ivanova3

1National Technical University of Ukraine “Igor Sikorsky Kyiv Polytechnic Institute”;
e-mail: alexfbt@gmail.com;
2Propharma Plant Ltd., Kyiv;
3Xema Ltd., Kyiv

Received: 18 July 2018; Accepted: 14 March 2019

One of the methods that have been widely used in the diagnosis of urogenital chlamydia is an enzyme-linked immunosorbent assay (ELISA), the use of which allows for differential diagnosis. In order to increase the efficiency of ELISA test kits production, for the kits for the diagnosis of urogenital chlamydia, based on the principle of indirect modification, following synthetic positive controls (PCs) can be used: a conjugate of IgM (IgA) normal immunoglobulins and monoclonal antibodies (McAbs) to C. trachomatis major outer membrane protein (MOMP). The goal of this work was to obtain high active and affinity McAbs to the C. trachomatis MOMP as well as the study of its immunobiological properties which are important for future biochemical approaches. The study was conducted using: polyclonal antibodies (PcAbs) to C. trachomatis; recombinant major outer membrane protein (MOMP) (191-354 a.r.; W4-W5); epitope mapping based on phage display technology. The original set from 16 clones of hybridomas, producers of McAbs to the C. trachomatis MOMP has been obtained. More than half of the tested McAbs (8 out of 14) were characterized by a rather high titer (≥1:800), and three of them had a titer of ≥1:1600. In general, the McAbs titer was correlated with the value of the affinity constant: McAbs with higher titles were characterized by a high value of the affinity constant. For McAbs with a titer of <1:800, the average Ka is 5.2×109 M-1, while for McAbs with a titer ≥1:800 – Ka = 10.7×109 M-1. Antigenic determinants of two McAbs 293F4 and 291F8 that actively competed with PcAbs are represented by two linear sequences of 320-325 a.r. and 326-330 a.r., respectively. The epitope, which interacts with McAb 296G2, is represented by a linear sequence of 347-352 a.r. McAb 296G2 did not show active competition with serum PcAbs. The resulting set of data allows selecting McAbs for use in PCs of the ELISA kit for the detection of IgA or IgM antibodies to C. trachomatis.