Studies on a 14-kilodalton surface protein of Onchocerca microfilariae.
A 14-kDa antigen present on the surface of uterine microfilariae of Onchocerca spp. has been identified using monoclonal antibodies. The antigen was also found in skin microfilariae, but in a masked or cryptic form. A complementary DNA clone encoding the epitope recognised by one of the monoclonal antibodies was identified in a lambda gt11 library. Nucleotide sequencing revealed that the 233-bp cDNA fragment codes for the carboxy-terminus of the antigen. The deduced amino acid sequence consists of three hydrophobic domains with high potential for beta-sheet formation. The amino-terminal hydrophobic domain is followed by 4 positively charged residues (positions 22-25) which contribute to the rather basic character of the protein. Another interesting feature of the polypeptide is its richness in phenylalanine (12.7%). From the sequence information, a synthetic peptide was synthesised which was recognised by one of the monoclonal antibodies directed against the 14-kDa antigen and a small number of sera from patients with onchocerciasis. The relevance of this to vaccination is discussed.
Conraths
F J
FJ
Division of Parasitology, National Institute for Medical Research, London, UK.
Worms
M J
MJ
Preece
G
G
Harnett
W
W
Parkhouse
R M
RM
D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000947:Antigens, Helminth / Q000032:analysis* / Q000737:chemistry / Q000276:immunology; D000954:Antigens, Surface / Q000032:analysis* / Q000737:chemistry / Q000276:immunology; D001483:Base Sequence; D015153:Blotting, Western; D003001:Cloning, Molecular; D004247:DNA; D005455:Fluorescent Antibody Technique; D015801:Helminth Proteins / Q000032:analysis* / Q000737:chemistry / Q000276:immunology; D008969:Molecular Sequence Data; D009854:Onchocerca / Q000276:immunology*; D011233:Precipitin Tests
D000911:Antibodies, Monoclonal; D000947:Antigens, Helminth; D000954:Antigens, Surface; D015801:Helminth Proteins; D004247:DNA