title: Characterization of acid phosphatase from the tick Haemaphysalis longicornis.
abstract: The full-length cDNA encoding acid phosphatase (HL-3) from Haemaphysalis longicornis was obtained by 5' rapid amplification of cDNA ends (RACE). The cDNA contained a 1137 bp open reading frame (ORF) coding for 356 amino acids with a predicted theoretical isoelectric point (pI) of 6.35 and molecular weight of 41.0 kDa. The recombinant protein was expressed in Escherichia coli. The enzyme could hydrolyze para-nitrophenyl phosphate (pNPP) substrate at an optimum pH of 5.0. Real-time RT-PCR analysis showed that the HL-3 transcripts were expressed in various stages of unfed ticks and were significantly induced by blood feeding. Furthermore, the expression of HL-3 in midguts was significantly higher than in other tested tissues of partially fed adult ticks. The transcripts of the HL-3 mRNA in lipopolysaccharide (LPS)-injected ticks were 1.75 times of the PBS-injected control; Theileria sergenti infected larvae expressed 3.86 more times than that of uninfected ones. Western blot analysis showed that rabbit antiserum against the recombinant rHL-3 could recognize a native protein of approximately 41.0 kDa in the lysates from different stages of ticks. Vaccination of rabbits with the rHL-3 conferred partial protective immunity against ticks, resulting in 28% mortality and 10.6% reduction in engorgement weight of adult ticks, respectively. These results suggested that the HL-3 was involved in tick innate immunity and could be used as a potential candidate antigen for the development of anti-tick vaccines.
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, 1 Xujianping, Yanchangbao, Lanzhou, Gansu Province 730046, PR China.
authors.forename: Ping
authors.initials: P
authors.lastname: Zhang
authors.forename: Zhancheng
authors.initials: Z
authors.lastname: Tian
authors.forename: Guangyuan
authors.initials: G
authors.lastname: Liu
authors.forename: Junren
authors.initials: J
authors.lastname: Xie
authors.forename: Jin
authors.initials: J
authors.lastname: Luo
authors.forename: Liyan
authors.initials: L
authors.lastname: Zhang
authors.forename: Hui
authors.initials: H
authors.lastname: Shen
mesh_terms: D000135:Acid Phosphatase / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D015971:Gene Expression Regulation, Enzymologic; D026863:Ixodidae / Q000201:enzymology* / Q000235:genetics; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010802:Phylogeny; D011487:Protein Conformation; D011817:Rabbits; D013984:Tick Infestations / Q000517:prevention & control / Q000662:veterinary; D014612:Vaccines / Q000276:immunology
chemical_list: D014612:Vaccines; D000135:Acid Phosphatase