Sun S H, Matsuura T, Sugane K
Department of Parasitology, Faculty of Medicine, Shinshu University, Asahi, Japan.
J Helminthol. 1991 Jun;65(2):149-58. doi: 10.1017/s0022149x00010622.
An immunodominant antigen of Dirofilaria immitis was studied using recombinant DNA techniques. The mRNA from D. immitis adult female worms was translated in vitro and a major 34 kDa antigenic polypeptide product was demonstrated by immunoprecipitation. cDNA was synthesized from mRNA and a lambda gt11 expression library was constructed and immunoscreened with dirofilariasis positive serum. A positive clone containing a nearly full length cDNA was isolated. The cDNA was 2415 bp in length and consisted of a single open reading frame followed by a long 3' non-coding region of 1446 bp. The open reading frame of 969 bp encoded a polypeptide of 322 amino acids with a molecular weight of 34,400. A cDNA fusion protein synthesized by bacteria (Escherichia coli JM109) using the expression vector pGEMEX-1 was identified as an immunodominant antigen by absorption experiments and had no cross-reactivity with sera from patients with other filarial species.
