Address for correspondence: Xiangrui Chen, Beijing Institute of Microbiology and Epidemiology, 20 Dongdajie Street, Beijing, China 100071.
bohaiwen{at}sohu.com
Ann. N.Y. Acad. Sci. 990: 527-534 (2003).
In this study, the fragment of 47 kDa gene (301 bp-1428 bp)
was cloned into a prokaryotic expression vector pBV220 to construct
a recombinant plasmid pBV-47. The
E. coli cells were transformed
with pBV-47 and the transformants were induced to express the
recombinant protein at 42°C. The expression product (40
kDa) was detected by SDS-PAGE analysis and the 40kDa protein
was recognized by mouse polyclonal antibodies against
O. tsutsugamushi Karp strain in western blot analysis. The entire 47 kDa protein
gene was inserted into an eukaryotic expression vector pcDNA3.1(+)
to construct a recombinant plasmid pcDNA3.1/47 and Balb/c mice
were immunized with recombinant pcDNA3.1/47, control vector
pcDNA3.1, PBS buffer, 40 kDa protein, and recombinant pcDNA3.1/47
plus 40 kDa protein (pcDNA3.1/47/40), respectively. The results
showed that spleen cells from pcDNA3.1/47/40-immunized mice
gave higher proliferation than other groups. A significant IgG
rise was detected in mice immunized with 40 kDa protein, but
it was less strong than that in mice immunized with pcDNA3.1/47/40.
The results suggested that immunization with pcDNA3.1/47 and
40 kDa protein simultaneously could induce a strong immune response.
