Molecular characterisation of the Ancylostoma-secreted protein family from the adult stage of Ancylostoma caninum.
The Ancylostoma-secreted proteins are a family of nematode-specific cysteine-rich secreted proteins belonging to the pathogenesis-related protein superfamily. Previously we reported that third stage infective larvae of Ancylostoma caninum produce two different Ancylostoma-secreted proteins, a single and double-domain Ancylostoma-secreted protein, designated as Ancylostoma-secreted protein-1 and Ancylostoma-secreted protein-2, respectively. Here we report that adult A. caninum hookworms produce and release four additional Ancylostoma-secreted proteins (Ancylostoma-secreted protein-3-6). Using antiserum against adult excretory/secretory products, Ancylostoma-secreted protein cDNAs were isolated from cDNA expression libraries. Immunolocalisation experiments using specific antisera indicated that the single-domain Ac-Ancylostoma-secreted protein-3 is located in the adult pharyngeal and oesophageal glands. Ac-Ancylostoma-secreted protein-4, Ancylostoma-secreted protein-5 and Ancylostoma-secreted protein-6 are composed of two pathogenesis-related protein domains linked in tandem as a heterodimorphic repeat. Ac-Ancylostoma-secreted protein-4 is localised to the cuticular surface of the adult hookworm, whereas Ac-Ancylostoma-secreted protein-5 was found in the intestinal brush border membrane, and Ancylostoma-secreted protein-6 in the cephalic and excretory glands. All of the adult Ancylostoma-secreted proteins were identified in excretory/secretory products of adult hookworms by Western blotting and are presumably released by the parasite. None of the adult Ancylostoma-secreted proteins were detected by immunoblotting in L3 extracts, although mRNAs of Ac-Ancylostoma-secreted protein-3 and Ac-Ancylostoma-secreted protein-4 were present in the larval stage. The functions of the adult Ancylostoma-secreted proteins are unknown, although the secretion of multiple family members by the adult suggests an important role in the establishment or maintenance of the parasitic relationship.
Zhan
Bin
B
Department of Microbiology and Tropical Medicine, Ross Hall, Room 736, 2300 Eye Street NW, The George Washington University, Washington, DC 20037, USA.
Liu
Yueyuan
Y
Badamchian
Mahnaz
M
Williamson
Angela
A
Feng
Jianjun
J
Loukas
Alex
A
Hawdon
John M
JM
Hotez
Peter J
PJ
D000722:Ancylostoma / Q000502:physiology*; D000818:Animals; D001483:Base Sequence; D015153:Blotting, Western / Q000379:methods; D015801:Helminth Proteins / Q000032:analysis* / Q000235:genetics / Q000378:metabolism*; D006790:Host-Parasite Interactions; D007106:Immune Sera / Q000302:isolation & purification; D007150:Immunohistochemistry / Q000379:methods; D008969:Molecular Sequence Data; D020133:Reverse Transcriptase Polymerase Chain Reaction
C480622:Ancylostoma-secreted protein 3, Ancylostoma caninum; C480623:Ancylostoma-secreted protein 4, Ancylostoma caninum; C480624:Ancylostoma-secreted protein 6, Ancylostoma caninum; D015801:Helminth Proteins; D007106:Immune Sera