[Expression of recombinant VP1 protein of enterovirus 71 and development of serological assay for detection of EV71 infection].

OBJECTIVE: To obtain a recombinant purified Enterovirus 71 VPI protein and establishment of an early, rapid and accurate serological ELISA (enzyme-linked immunosorbent assay) for detection of EV71 infection.

METHODS: VP1 gene was amplified by PCR and clonel into pET-21b (+) vector, the positive recombinant plasmid were transformed into E. coli BI21(DE3), and was induced with IPTG, the recombinant protein by SDS-PAGE and Western Blot assays. Finally, the recombinant purified VP1 protein was used as a coated antigen for detection of serum anti-IgM and IgG against EV71 by ELISA.

RESULTS: The purified VP1 was obtained, and it can be recognized by sera of patients with EV71 infection associated with hand-foot-mouth disease. The A values of anti-EV71 IgM and IgG were significantly elevated as compared to healthy objects and HFMD patients without EV71 infection (P < 0.05). The sensitivity and specificity of IgM to EV71 were 73% and 77% compared with the RT-PCR results, respectively;and those of IgG being 82% and 83%, respectively.

CONCLUSIONS: The recombinant protein VP1 was produced and purified, and it was proved to have a good antigenicity and could be used to develop a serological diagnosis kit for EV71 infection in the future.