Estudo de proteínas antigênicas do Treponema pallidum

Abstract

The incidence of syphilis has increased alarmingly in recent decades, with an estimated 6 million new cases per year in the world. The diagnosis of syphilis remains a challenge, due to the difficulty of Treponema pallidum in vitro culture. In recent years, new treponemal tests have been developed using recombinant T. pallidum antigens. This approach confers greater specificity and sensitivity for the screening of patients with syphilis. This study aimed to the production of recombinant antigens for the development of a more efficient serological diagnosis for the detection of T. pallidum. The selection of antigens was based on proteomic studies with the aid of bioinformatics programs. Three genes coding for the Tp0684, Tp0750 and Tp0792 proteins were selected and submitted to chemical synthesis, cloned in the pAE vector; the proteins were expressed in E. coli BL21 Star™ and purified by affinity chromatography. The antigenicity of recombinant proteins rTp0684, rTp0750 and rTp0792 were evaluated by Western blot and ELISA with sera from patients with primary syphilis (n = 6), latent syphilis (n = 34) and uninfected control sera (n = 10). The three recombinant proteins were recognized by sera from patients with primary syphilis and latent syphilis in Western blot and ELISA, demonstrating be antigenic. These results indicate that the antigens produced have the potential to be used in the development of serological tests for the screening of patients with syphilis. In addition, the strategy of using recombinant proteins can ensure an increase in the specificity of serologic tests reducing the occurrence of false positive results. On the other hand, enables a rational study targets with high sensitivity, decreasing significantly negative and false positive results.