Induction of protective immunity against scrub typhus with a 56-kilodalton recombinant antigen fused with a 47-kilodalton antigen of Orientia tsutsugamushi Karp.
A partial gene sequence encoding the 56-kD scrub typhus antigen (Sta56) was amplified from genomic DNA of the Orientia tsutsugamushi Karp strain by a polymerase chain reaction (PCR). The PCR product was ligated with the 47-kD scrub typhus antigen (Sta47) gene in the pQE30/47 expression vector, and the resulting recombinant expression vector was designated pQE30/56-47. A fusion antigen (Sta56-47) was expressed in Escherichia coli cells transformed with pQE30/56-47 after induction with isopropyl-beta-d-thiogalactopyranoside. The Sta56-47 antigen was recognized by both Sta47 and Sta56 immune sera and by immune serum to Sta56-47 in an immunoblot assay. This antigen was purified and used to immunize BALB/c mice. The animals immunized with Sta56-47 exhibited profound humoral and cellular immune responses, as well as increased resistance to O. tsutsugamushi Karp compared with mice immunized with Sta56 or Sta47. These results strongly suggest that Sta56-47 contains antigenic epitopes of the Sta56 and Sta47 antigens of O. tsutsugamushi Karp, and is a more suitable candidate for replacing whole-cell antigen of O. tsutsugamushi Karp to induce protective immunity against scrub typhus.
Yu
Yuefei
Y
Beijing Institute of Microbiology and Epidemiology, Fengtai, Beijing, People's Republic of China.
Wen
Bohai
B
Wen
Bogui
B
Niu
Dongsheng
D
Chen
Meiling
M
Qiu
Ling
L
D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis; D000942:Antigens, Bacterial / Q000008:administration & dosage* / Q000276:immunology; D001483:Base Sequence; D017931:DNA Primers; D004591:Electrophoresis, Polyacrylamide Gel; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D012285:Orientia tsutsugamushi / Q000276:immunology*; D011993:Recombinant Fusion Proteins / Q000008:administration & dosage* / Q000276:immunology / Q000302:isolation & purification; D012612:Scrub Typhus / Q000276:immunology* / Q000517:prevention & control
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D017931:DNA Primers; D011993:Recombinant Fusion Proteins