Objective: To construct recombinant protein of Neisserial surface protein A (NspA) and determine the anti-NspA antibody levels using it as antigen in patients at the recovery stage of Neisseria meningitides, so as to explore the possibility of using NspA protein as the antigen for designing a novel vaccine for epidemic Neisseria meningitides.
Methods: NspA gene was cloned from the isolated pathogen of patients with Neisseria meningitides to construct the prokaryotic expression vector. NspA protein was expressed in the form of soluble protein in E.coli and purified by GSTrap FF affinity chromatography. The antibody titers of recovery-stage patients with Neisseria meningitides were determined using the purified recombinant NspA.
Results: Functional NspA was successfully expressed with Mr; being 44 000. The purified NspA had a good biological function. Antibodies against NspA could be detected in the sera of patients at the recovery stage of Neisseria meningitides using NspA protein. Positive rate reached 90% when titer was 1:40.
Conclusion: Recombinant NspA protein was expressed successfully and it could be used to detect the anti-NspA antibodies in the sera of patients with Neisseria meningitides at recovery stage.