Protective immunity induced in mice by F8.1 and F8.2 antigens purified from Schistosoma mansoni eggs

Abstract

Schistosoma mansoni soluble egg antigens (SEA) were fractionated by isoelectric focusing, resulting in 20 components, characterized by pH, absorbance and protein concentration. The higher absorbance fractions were submitted to electrophoresis, and fraction 8 (F8) presented a specific pattern of bands on its isoelectric point. Protein 3 was observed only on F8, and so, it was utilized to rabbit immunization, in order to evaluate its capacity of inducing protective immunity. IgG antibodies from rabbit anti-F8 serum were coupled to Sepharose, and used to obtain the specific antigen by affinity chromatography. This antigen, submitted to electrophoresis, presented two proteic bands (F8.1 and F8.2), which were transferred to nitrocellulose membrane (PVDF) and sequenciated. The homology of F8.2 to known proteins was determined using the Basic Local Alignment Search Tool program (BLASTp). Significant homologies were obtained for the rabbit cytosolic Ca2+ uptake inhibitor, and for the bird a1-proteinase inhibitor. Immunization of mice with F8.1 and F8.2, in the presence of Corynebacterium parvum and Al(OH)3 as adjuvant, induced a significant protection degree against challenge infection, as observed by the decrease on worm burden recovered from portal system.

AdultBrugia malayimitochondrial and nuclear fractions impart Th1-associated sizeable protection against infective larval challenges inMastomys coucha

“…Significant levels of protection against homologous challenge infection have been observed with the L3 attenuated by irradiation (Oothuman et al , 1979; Bancroft & Devaney, 1993; Bleiss et al , 2002; Lustigman et al , 2003). Crude or partially purified somatic and secretory antigens have been shown to provide partial protection against parasitic helminth infection (Schallig & Van Leeuwen, 1997; Ferreira et al , 1998; Abdel Rahman et al , 2005). Protection studies using partially purified antigens of animal filariids revealed marginally better efficacy using various methods of purification (Storey & Mettias, 1980; Sumati et al , 1990; Dikshit & Misra, 1994; Dixit et al , 2006).…”