Immunological cross-reaction between an Onchocerca paramyosin-like molecule and a microfilaria surface antigen

A monoclonal antibody (2A5B9), previously shown to be reactive with a 14 kD surface associated antigen of Onchocerca microfilariae, was found to recognise a 92 kD molecule present in an adult worm extract. The antibody was used to select cDNA clones with a coding capacity larger than 14 kD, from a lambda gt11 library of O. volvulus. Nucleotide sequencing of the cDNA of one such clone revealed extensive homology to the myosin (unc-54) and paramyosin (unc-15) genes of Caenorhabditis elegans, similarly to myosin and paramyosin genes of Onchocerca volvulus, Brugia malayi, Dirofilaria immitis and Schistosoma mansoni. The immunological implications of antigenic cross-reactivity between a surface molecule and paramyosin, a known protective antigen, are discussed.