title: Cloning and characterization of a cDNA clone encoding calreticulin from Haemaphysalis qinghaiensis (Acari: Ixodidae).
abstract: The application of anti-tick vaccine has been shown to be the most promising alternative strategy compared to the current use of acaricides that suffer from a number of serious limitations. The success of this method is dependent upon identification and cloning of potential tick vaccine antigens. Previously, we have cloned 21 positive clones (named from Hq02 to Hq22) by immunoscreening complimentary DNA (cDNA) libraries of Haemaphysalis qinghaiensis; however, some of those clones did not contain open reading frames (ORF). In this study, we amplified the entire sequence of Hq07 by using rapid amplification of the cDNA ends. Hq07 contains an ORF of 1,233 bp that encodes for 410 amino acid residues with a coding capacity of 47 kDa. Search of the cloned sequences against GenBank revealed that Hq07 is a calreticulin (CRT)-similar clone and designated HqCRT. Expression analysis by reverse transcription-polymerase chain reaction showed that this gene is ubiquitously expressed at different developmental stages and in different tissues of H. qinghaiensis. The gene was expressed as glutathione S-transferase-fused proteins in a prokaryotic system. Western blot analysis revealed that native HqCRT was secreted into their hosts by ticks during blood sucking. Vaccination of sheep with rHqCRT conferred protective immunity against ticks, resulting in 54.3% mortality in adult ticks, compared to the 38.7% death rate in the control group. These results demonstrated that rHqCRT might be a useful vaccine candidate antigen for biological control of H. qinghaiensis.
authors: Key Laboratory of Veterinary Parasitology of Gansu Province, State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou 730046, China.
authors: Jinliang
authors: J
authors: Gao
authors: Jianxun
authors: J
authors: Luo
authors: Ruiquan
authors: R
authors: Fan
authors: Volker
authors: V
authors: Fingerle
authors: Guiquan
authors: G
authors: Guan
authors: Zhijie
authors: Z
authors: Liu
authors: Youquan
authors: Y
authors: Li
authors: Haiping
authors: H
authors: Zhao
authors: Miling
authors: M
authors: Ma
authors: Junlong
authors: J
authors: Liu
authors: Aihong
authors: A
authors: Liu
authors: Qiaoyun
authors: Q
authors: Ren
authors: Zhisheng
authors: Z
authors: Dang
authors: Chihiro
authors: C
authors: Sugimoto
authors: Hong
authors: H
authors: Yin
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D037282:Calreticulin / Q000737:chemistry / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics*; D005260:Female; D007114:Immunization; D026863:Ixodidae / Q000235:genetics* / Q000254:growth & development / Q000276:immunology / Q000378:metabolism; D008297:Male; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000276:immunology; D017422:Sequence Analysis, DNA; D012756:Sheep; D012757:Sheep Diseases / Q000469:parasitology / Q000517:prevention & control; D013984:Tick Infestations / Q000469:parasitology / Q000517:prevention & control / Q000662:veterinary; D014612:Vaccines / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology; D014614:Vaccines, Synthetic / Q000008:administration & dosage / Q000276:immunology
chemical_list: D037282:Calreticulin; D018076:DNA, Complementary; D011994:Recombinant Proteins; D014612:Vaccines; D014614:Vaccines, Synthetic