Proteomic analysis identification of antigenic proteins in Gnathostoma spinigerum larvae

Gnathostoma spinigerum is the causative agent of human gnathostomiasis. The advanced third stage larva (AL3) of this nematode can migrate into the subcutaneous tissues, including vital organs, often producing severe pathological effects. This study performed immuno-proteomic analysis of antigenic spots, derived from G. spinigerum advanced third stage larva (GSAL3) and recognized by human gnathostomiasis sera, using two-dimensional (2-DE) gel electrophoresis based-liquid chromatography/tandem mass spectrometry (LC/MS-MS), and followed by the aid of a database search. The crude GSAL3 extract was fractionated using IPG strips (pH 3-11NL) and followed by SDS-PAGE in the second dimension. Each gel was stained with colloidal Coomassie blue or was electro-transferred onto a nitrocellulose membrane and probed with gnathostomiasis human sera by immunoblotting. Individual Coomassie-stained protein spots corresponding to the antigenic spots recognized by immunoblotting were excised and processed using LC/MS-MS. Of the 93 antigenic spots excised, 87 were identified by LC/MS-MS. Twenty-seven protein types were found, the most abundant being Ascaris suum37. Six spots showed good quality spectra, but could not be identified. This appears to be the first attempt to characterize antigenic proteins from GSAL3 using a proteomic approach. Immuno-proteomics shows promise to assist the search for candidate proteins for diagnosis and vaccine/drug design and may provide better understand of the host-parasite relationship in human gnathostomiasis.