title: A serine proteinase inhibitor (serpin) from ixodid tick Haemaphysalis longicornis; cloning and preliminary assessment of its suitability as a candidate for a tick vaccine.
abstract: Rapid amplification of the cDNA ends (RACE) and primers designed based on a conserved serpin amino acid motif (NAVYFKG) were used to clone a 1350bp cDNA which encodes a 378 polypeptide with high sequence similarity to several known serpins. We have named this gene as Haemaphysalis longicornis serpin-1 (HLS1). Northern blotting and reverse transcription (RT)-PCR analysis of total RNA from unfed or partially fed whole ticks as well as dissected tick organs revealed that transcription of HLS1 mRNA was induced by blood meal feeding during the slow feeding phase (24-48 h post-attachment) only in the tick midguts. Vaccination of rabbits with recombinant HLS1 (rHLS1) expressed in Escherichia coli resulted in 43.9 and 11.2% mortality of nymph and adult ticks which were fed on immunized rabbits. Polyclonal rabbit antibodies to tick saliva did not react with rHLS1, suggesting that native HLS1 was not secreted into the host during tick feeding. rHLS1 could be a potential candidate for a cocktail anti-tick vaccine.
authors.affiliation: Department of Infectious Diseases, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan.
authors.forename: Maiko
authors.initials: M
authors.lastname: Sugino
authors.forename: Saiki
authors.initials: S
authors.lastname: Imamura
authors.forename: Albert
authors.initials: A
authors.lastname: Mulenga
authors.forename: Mie
authors.initials: M
authors.lastname: Nakajima
authors.forename: Akiko
authors.initials: A
authors.lastname: Tsuda
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Ohashi
authors.forename: Misao
authors.initials: M
authors.lastname: Onuma
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D007114:Immunization; D026863:Ixodidae / Q000737:chemistry / Q000276:immunology* / Q000378:metabolism; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000096:biosynthesis; D011817:Rabbits; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000276:immunology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015842:Serine Proteinase Inhibitors / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D015843:Serpins / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D014612:Vaccines / Q000276:immunology*
chemical_list: D018076:DNA, Complementary; D012333:RNA, Messenger; D011994:Recombinant Proteins; D015842:Serine Proteinase Inhibitors; D015843:Serpins; D014612:Vaccines