Bioinformatic Prediction and Production of Four Recombinant Proteins from Different Developmental Stages of Trichinella spiralis and Testing of Their Diagnostic Sensitivity in Mice.

Background: Trichinellosis is a serious food-borne parasitic zoonosis, thus finding high quality antigens is the key to serodiagnosis of trichinosis. This article reports the characterization and sensitivity of four recombinant proteins expressed by four genes ( Wn10 , Zh68 , T668 , and Wm5 ) from different developmental stages of Trichinella spiralis for the diagnosis of trichinellosis in mice.
Methods: This study was conducted in Jilin University and National Institute of Parasitic Diseases of Chinese Center for Disease Control and Prevention in 2017-2018. The structures and functions of the proteins encoded by four genes were predicted by bioinformatics analysis. The four genes were cloned and expressed, and the recombinant proteins were purified. Anti- Trichinella IgM and IgG antibodies in the sera of mice infected with T. spiralis from 1-45 d post-infection (dpi) were evaluated by ELISA.
Results: The optimal antigen epitopes of four proteins (P1, P2, P3, and P4) encoded by the four genes from T- and B-cells were predicted, and four purified recombinant proteins (r-P1, r-P2, r-P3, and r-P4) were successfully produced. For IgM, the antibody levels detected by the four recombinant antigens were approximately equal to the cut-off value. Anti- Trichinella IgG antibodies were first detected by r-P1 at 8 dpi, followed by r-P2, r-P3, and r-P4 at 10 dpi, 14 dpi, and 16 dpi, respectively, and the antibody levels remained high until 45 dpi.
Conclusion: The recombinant antigens r-P1, r-P2, r-P3, and r-P4 could be antigens that react with antibodies, they showed high sensitivity in the detection of anti- Trichinella IgG antibodies in mice. Among these proteins, r-P1 may be a candidate antigen for the detection of anti- Trichinella IgG antibodies in the early infection phase and exhibited the best sensitivity among the antigens.
Competing Interests: Conflict of interest We have no conflict of interest related to this study.
(Copyright © 2021 Zhai et al. Published by Tehran University of Medical Sciences.)