title: Molecular cloning, expression, and characterization of a putative activation-associated secreted protein from Angiostrongylus cantonensis.
abstract: Activation-associated secreted protein (ASP) had been found in many helminthes, which was associated with pathogenesis and stage transition. A complementary DNA (cDNA) sequence encoding a putative two-domain ASP was obtained from an Angiostrongylus cantonensis fourth-stage larvae cDNA library, which we designated as AgASP. The cDNA of AgASP contains an open reading frame encoding 424 amino acids, the first 19 residues being a putative secretion signal. The expression pattern of this protein was investigated by real-time polymerase chain reaction and Western blot. We found that this protein expressed most highly in the brain-stage larvae (Lbr) of this parasite and existed in the excretory/secretory products of this stage. Immunofluorescence showed it existed in the lumen of the Lbr. The recombinant protein can be recognized by the infection sera from mice (nonpermissive host), while it cannot be recognized by infection sera from rats (permissive host). The infiltration of neutrophils in infected nonpermissive host can be lessened by immunizing this host with this protein (immunized vs control group, 13.7 ± 10.2 vs 65.5 ± 19.2). These findings suggest that this protein plays a role in the pathogenesis of human angiostrongyliasis and is worthy of further study.
authors.affiliation: Department of Parasitology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080 Guangdong Province, People's Republic of China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Yang
authors.forename: Zhuoya
authors.initials: Z
authors.lastname: Li
authors.forename: Hualiang
authors.initials: H
authors.lastname: He
authors.forename: Mei
authors.initials: M
authors.lastname: Cheng
authors.forename: Qian
authors.initials: Q
authors.lastname: Liu
authors.forename: Dongjing
authors.initials: D
authors.lastname: Zhang
authors.forename: Jing
authors.initials: J
authors.lastname: Chen
authors.forename: Xiansheng
authors.initials: X
authors.lastname: Wu
authors.forename: Ai
authors.initials: A
authors.lastname: He
authors.forename: Xiaoying
authors.initials: X
authors.lastname: Zheng
authors.forename: Yu
authors.initials: Y
authors.lastname: Wu
authors.forename: Zhongdao
authors.initials: Z
authors.lastname: Wu
authors.forename: Ximei
authors.initials: X
authors.lastname: Zhan
mesh_terms: D017185:Angiostrongylus cantonensis / Q000235:genetics* / Q000472:pathogenicity*; D000818:Animals; D015153:Blotting, Western; D001921:Brain / Q000469:parasitology; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D020869:Gene Expression Profiling; D015801:Helminth Proteins / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D016366:Open Reading Frames; D021382:Protein Sorting Signals; D051381:Rats; D017207:Rats, Sprague-Dawley; D060888:Real-Time Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D037521:Virulence Factors / Q000235:genetics* / Q000378:metabolism*
chemical_list: D018076:DNA, Complementary; D015801:Helminth Proteins; D021382:Protein Sorting Signals; D037521:Virulence Factors