Ac-SAA-1, an immunodominant 16 kDa surface-associated antigen of infective larvae and adults of Ancylostoma caninum.
A cDNA encoding a surface-associated antigen was cloned from an Ancylostoma caninum infective larvae (L(3)) cDNA library by immunoscreening with pooled human immune sera. The sera were obtained from individuals living in an Ancylostoma duodenale hookworm-endemic region of China, who had light intensity infections and high antibody titers against A. caninum L(3). Ancylostoma caninum surface-associated antigen-1 is encoded by an 843 bp mRNA with a predicted open reading frame of 162 amino acids. Recombinant Ancylostoma caninum surface-associated antigen-1 was expressed in Escherichia coli and used to prepare a specific antiserum. A Western blot with anti-Ancylostoma caninum surface-associated antigen-1 specific antiserum showed that native Ancylostoma caninum surface-associated antigen-1 protein is expressed by both L(3) and adult hookworms; RT-PCR confirmed that the mRNA is transcribed in both stages. In adult hookworms, the protein localised to the basal layer of the cuticle and hypodermis of adult worms. Serological analysis determined that recombinant Ancylostoma caninum surface-associated antigen-1 protein is recognised by 61% of human sera from a Necator americanus hookworm endemic area in China, indicating the antigen is immunodominant. Anti-Ancylostoma caninum surface-associated antigen-1 antiserum partially inhibited (46.7%) invasion of hookworm L(3) into dog skin in vitro. Together these results suggest that Ancylostoma caninum surface-associated antigen-1 offers promise as a protective vaccine antigen.
Department of Microbiology and Tropical Medicine, The George Washington University and Sabin Vaccine Institute, 2300 Eye Street NW, Washington, DC 20037, USA.
Bin
B
Zhan
Yan
Y
Wang
Yueyuan
Y
Liu
Angela
A
Williamson
Alex
A
Loukas
John M
JM
Hawdon
Hae-Chou
HC
Xue
Shu-Hua
SH
Xiao
Peter J
PJ
Hotez
D000595:Amino Acid Sequence; D000722:Ancylostoma / Q000276:immunology*; D000724:Ancylostomiasis / Q000453:epidemiology / Q000276:immunology*; D000818:Animals; D000947:Antigens, Helminth / Q000032:analysis* / Q000235:genetics / Q000276:immunology; D000954:Antigens, Surface / Q000032:analysis / Q000235:genetics / Q000276:immunology; D001483:Base Sequence; D002681:China / Q000453:epidemiology; D018076:DNA, Complementary / Q000235:genetics; D004285:Dogs; D019353:Endemic Diseases; D015723:Gene Library; D006801:Humans; D007106:Immune Sera / Q000276:immunology; D016056:Immunodominant Epitopes / Q000032:analysis* / Q000235:genetics / Q000276:immunology; D008969:Molecular Sequence Data; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D012867:Skin / Q000469:parasitology
D000947:Antigens, Helminth; D000954:Antigens, Surface; D018076:DNA, Complementary; D007106:Immune Sera; D016056:Immunodominant Epitopes