Treponema pallidum recombinant antigens

Treponema pallidum is a spirochete bacterium that causes syphilis. This bacterium is often called a “hidden pathogen” because highly immunogenic lipoproteins are found in the periplasmic space, while the outer membrane contains numerous non-immunogenic proteins. Detection of syphilis is based on serological tests, which are the only means of identifying asymptomatic cases. The traditional diagnostic approach involves a combination of two types of tests. To assess disease activity, tests for non-treponemal antibodies are used, the titers of which decrease with treatment. Treponema-specific tests usually confirm the immune response but do not indicate the time frame of infection. Such serological tests usually detect class G antibodies, which indicate a mature immune response in primary and secondary syphilis, while IgM indicates a recent infection. In the diagnosis, several key proteins of T. pallidum are most important:
TprK (p41) is a protein characterized by significant antigenic variation. Tp47 also exhibits antigenic variability and is a highly immunogenic membrane-associated lipoprotein often used in serological tests. Tp17 is also recognized as an immunodominant antigen during syphilis.
Vitrotest produces recombinant mosaic proteins produced in the E. coli expression system. These proteins are analogs of the immunogenic proteins p17, p41, and p47 of T. pallidum and contain immunodominant epitopes. They have been tested for suitability in enzyme-linked immunosorbent assay (ELISA) by many years of experience.