title: Identification and location of albumin-like antigens in third-stage larva of W. bancrofti, in adult forms of Litomosoides chagasfilhoi and in the free-living nematode Caenorhabditis elegans.
abstract: Antigens resembling those of host proteins have been identified on the surface of several filarial parasites, such as immunoglobulins and serum albumins. The origin of albumin-like antigens on filarial parasites remains unclear. Several authors suggested that they have been adsorbed, or that they were metabolic waste products from nutritional utilization of human albumin, or perhaps a contamination with human products. This study searched for human albumin-like antigens by Western blot and ultrastructural analyses on filarial parasites, third stage of W. bancrofti and adult females of Litomosoides chagasfilhoi, and on the free-living Caenorhabditis elegans nematode. Our results showed approximately 67kDa proteins recognized by anti-human albumin antibodies on extracts and excretory-secretory (ES) products of the third-stage W. bancrofti. Similar albumin-like proteins were also detected on the filarial parasite L. chagasfilhoi and on C. elegans extracts. The immunocytochemistry analysis showed human albumin-like antigens on similar tissues of these nematodes. These results provide evidence that these proteins have antigenic similarity and similar distribution in nematodes tissues. Our observations suggest that albumin-like antigens presented on filarial parasites are not acquired from the host, but rather are shared antigenic determinants found even in the third-stage larvae recovered from the invertebrate host.
authors.affiliation: Departamento de Biologia Celular e Ultraestrutura, Centro de Pesquisas Aggeu Magalhães (FIOCRUZ), Brazil.
authors.forename: L F
authors.initials: LF
authors.lastname: Silva
authors.forename: F A S
authors.initials: FA
authors.lastname: Brayner
authors.forename: A C O
authors.initials: AC
authors.lastname: Santos
authors.forename: R M
authors.initials: RM
authors.lastname: Lanfredi
authors.forename: C A
authors.initials: CA
authors.lastname: Peixoto
mesh_terms: D000418:Albumins / Q000032:analysis*; D000818:Animals; D000947:Antigens, Helminth / Q000032:analysis*; D015153:Blotting, Western; D017173:Caenorhabditis elegans / Q000737:chemistry* / Q000276:immunology / Q000648:ultrastructure; D029742:Caenorhabditis elegans Proteins / Q000032:analysis; D005260:Female; D005370:Filarioidea / Q000737:chemistry* / Q000276:immunology / Q000648:ultrastructure; D007150:Immunohistochemistry; D007814:Larva; D046529:Microscopy, Electron, Transmission; D014958:Wuchereria bancrofti / Q000737:chemistry* / Q000276:immunology / Q000648:ultrastructure
chemical_list: D000418:Albumins; D000947:Antigens, Helminth; D029742:Caenorhabditis elegans Proteins