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Identification of a novel potential antigen for early-phase serodiagnosis of leptospirosis
Fernanda O Neves1, Patricia A E Abreu, Silvio A Vasconcellos
1Centro de Biotecnologia, Instituto Butantan, Avenida Vital Brazil, 1500, 05503-900, Sao Paulo, SP, Brazil.
Abstract:
This study examined four genes encoding for predicted membrane proteins selected from the genome sequences of Leptospira interrogans. Genes were cloned and the proteins expressed in E. coli. Immunoblotting analysis of the recombinants with sera from early and convalescent phases of a leptospirosis patient showed that two proteins, namely Lp29 and Lp49, were reactive with serum from both phases of the illness. These data were further confirmed in enzyme-linked immunosorbent assay using sera from both phases of seventeen confirmed leptospirosis specimens, suggesting that these proteins are presented to the host immune system during infection. In the early phase, anti-Lp29 IgM was detected in all sera when microscopic agglutination tests (MAT), the reference method for diagnosis of leptospirosis, were negative. The gene encoding Lp49 is conserved among five tested leptospiral pathogenic serovars, while Lp29 is present in serovars that are predominant in urban settings. These recombinant antigens might be valuable for serodiagnosis of both phases of leptospirosis.
Insights
Researchers identified two Leptospira interrogans membrane proteins, Lp29 and Lp49, that are reactive to patient sera in both early and late leptospirosis phases. These proteins show potential for improved leptospirosis serodiagnosis.
Area of Science:
- Microbiology
- Immunology
- Infectious Diseases
Background:
- Leptospira interrogans causes leptospirosis, a significant zoonotic disease.
- Accurate serodiagnosis is crucial for managing leptospirosis.
- Current diagnostic methods may have limitations in early disease detection.
Purpose of the Study:
- To identify and characterize novel Leptospira interrogans membrane proteins for diagnostic purposes.
- To evaluate the reactivity of selected proteins with patient sera from different disease phases.
- To assess the potential of these proteins as diagnostic antigens for leptospirosis.
Main Methods:
- Selection and cloning of four Leptospira interrogans membrane protein genes.
- Expression of recombinant proteins in E. coli.
- Immunoblotting and enzyme-linked immunosorbent assay (ELISA) using human sera from leptospirosis patients.
- Microscopic agglutination test (MAT) as a reference diagnostic method.
Main Results:
- Two recombinant proteins, Lp29 and Lp49, showed reactivity with sera from both early and convalescent phases of leptospirosis.
- Anti-Lp29 IgM was detected in early-phase sera when MAT results were negative.
- The Lp49 gene is conserved in pathogenic serovars, while Lp29 is prevalent in urban-associated serovars.
Conclusions:
- Lp29 and Lp49 are immunogenic and recognized by the host immune system during Leptospira interrogans infection.
- These recombinant proteins hold promise as valuable antigens for the serodiagnosis of both early and late-stage leptospirosis.
- Lp29 may be particularly useful for early leptospirosis detection, even when traditional methods are negative.
