Cross-reactive surface antigens on three stages ofBrugia malayi,B. pahangiandB. timori

Abstract

Surface antigens of three stages of three species of the filarial nematode genus Brugia have been analysed by radio-iodination and immunoprecipitation. These surface antigens have been shown to be characteristic for each stage by polyacrylamide gel electrophoresis. For example, infective larvae and adult worms have relatively complex patterns while microfilariae have few bands which are not found when other stages are radio-isotope labelled by the same technique. The surface antigens of Brugia malayi, B. timori and B. pahangi adult worms are all closely homologous, as are the surface antigens of infective larvae of the same three species, and of microfilariae of B. malayi and B. pahangi. Immunoprecipitation revealed that antibody raised in mice against one stage or species reacted with surface antigens from other stages and species. For example, sera raised against B. pahangi male adults reacted strongly with surface antigens from all three species. This cross-reactivity was dominant despite the apparent stage-specificity of the surface pattern seen on SDS-PAGE analysis. Moreover, in cross-immunization experiments, infective larvae were able to stimulate a secondary antibody response in mice previously primed with microfilarial surface antigens. The major microfilarial surface antigens (of mol. wt 65-70 000 Daltons) were recognized by serum antibody from microfilariae-, infective larvae- or adult-infected animals. Thus, although the dominant antigens from each stage are of different molecular weight, cross-reactions with stage-specific antisera suggest that there must be shared epitopes on Brugia surface antigens from each stage. Such shared antigenic determinants dominate the immune response, although other evidence, including the differences in molecular weight, indicates the existence of stage- and species-specific components.

Expression of different filarial parasite adult stage antigens during course of DEC treatment in mouse model of Brugian filariasis

“…Nevertheless, parasite surface has received special attention for identifying prominent and potentially protective antigens. 29 kDa molecular weight protein of B. malayi has been found to bear epitopes cross-reactive between different stages and species of filariae (Kaushal et al, 1982;Maizels et al, 1983aMaizels et al, , 1983bMaizels et al, , 1983c. This antigen has close analogues in 29 to 30 kDa proteins from the adult worms of other lymphatic filariids, B. pahangi, B. timori and W. bancrofti.…”

“…The somatic antigens have been fractionated earlier derived from a number of filarial parasites including W. bancrofti (Michael et al, 1996a); and B. malayi (Lal and Ottesen, 1988;Maizels et al, 1983aMaizels et al, , 1983b1983c;Selkirk et al, 1986). A number of antigenic molecules viz.…”

Monoclonal antibody to a unique surface epitope of the human filaria Brugia malayi identifies infective larvae in mosquito vectors.

“…The widespread crossreactivity of filarial antigens and that of surface antigens ofBrugia in particular have been analyzed extensively (20)(21)(22), but to date no species or stage-specific component(s) has been identified. As pointed out by Maizels et al (20), however, the biochemical and antigenic similarity between Brugia surface molecules does not preclude the existence of epitopes unique both to stage and species.…”

Identification of the major soluble cuticular glycoprotein of lymphatic filarial nematode parasites (gp29) as a secretory homolog of glutathione peroxidase.

“…In contrast to these conserved structural elements, the nematode cuticle exhibits an extremely restricted profile of soluble constituent proteins that may be species-or stagespecific (3,4). The major protein of adult lymphatic filarial parasites defined by surface labeling is a 29-kDa glycoprotein (gp29) that appears to be expressed after infection of the mammalian host (5)(6)(7)(8)(9)(10)(11). Peptide mapping has shown that gp29 from Brugia pahangi and Brugia malayi are highly homologous (8), and the 29-kDa surface-labeled protein from Brugia timori (5) and Wuchereria bancrofti (6) probably represents the same molecule.…”

“…The major protein of adult lymphatic filarial parasites defined by surface labeling is a 29-kDa glycoprotein (gp29) that appears to be expressed after infection of the mammalian host (5)(6)(7)(8)(9)(10)(11). Peptide mapping has shown that gp29 from Brugia pahangi and Brugia malayi are highly homologous (8), and the 29-kDa surface-labeled protein from Brugia timori (5) and Wuchereria bancrofti (6) probably represents the same molecule. In adult B. malayi gp29 is synthesized in the syncytial hypodermis, exported to the cuticle, and released into the external environment during in vitro culture (9,10).…”