Roles of partially purified antigens from Gnathostoma spinigerum larvae on antibody production by human B cell culture.

A 24 kDa protein from advanced third stage Gnathostoma spinigerum larvae (GsAL3) is used for gnathostomiasis serodiagnosis. This study investigated whether partially purified protein antigen (Ag) from GsAL3 (Gnath Ag), prepared by simple gel filtration chromatography, could be used for serodiagnosis. Using DNA microarray analysis, significant gene expression related to immunoreactivity was examined in peripheral blood mononuclear cells (PBMC) cocultured with Gnath Ag. Antigenicity was then determined by its capacity to induce antibody production among purified naive B cells stimulated with Gnath Ag and anti-CD40. Seven and 14 days post-exposure, immunoglobulin levels (Igs) in culture supernatants were determined by enzyme-linked immunosorbent assay. The Gnath Ag stimulated PBMC had a significant increase in gene expression related to an innate immune response and decreased cell mediated immunity, but the expression of gene related antibody production was not markedly increased. The Gnath Ag stimulated naive B cells or lipopolysaccharide primed B cells to produce low levels of specific antibody. Our findings support the assertion that partially purified Gnath Ag possess low antigenicity for Ig induction. Further studies are needed to improve G. spinigerum larva Ag for serodiagnosis.