Evaluation of recombinant HP6-Tsag, an 18 kDa Taenia saginata oncospheral adhesion protein, for the diagnosis of cysticercosis

Abstract

With the objective of providing inexpensive and reproducible assays for the detection of antibodies indicating exposure to Taenia saginata and Taenia solium, we have evaluated the diagnostic utility of the T. saginata oncosphere adhesion protein (HP6-Tsag), expressed in baculovirus (HP6-Bac) and bacteria (HP6-GST [glutathione S-transferase]), employing enzyme-linked immunosorbent assays (ELISAs) and sera from T. saginata infected cattle, T. solium infected pigs and serum and cerebrospinal fluid (CSF) samples from clinically defined T. solium neurocysticercosis (NCC) patients. The two recombinant proteins were antigenic in all three systems, with the signal to background ratio of the HP6-Bac ELISA slightly higher than that for the HP6-GST ELISA. Assay performance in cattle was similar to previously described peptide-based ELISA assays, although NCC sample sensitivity/specificity was marginally better. The sensitivity of the HP6-Bac and HP6-GST ELISAs was close for active human NCC (77.4 and 80.6% for serum and 76.9 and 73.1% for CSF samples, respectively). In inactive human NCC, however, the sensitivity of the HP6-Bac ELISA was almost twice that of the HP6-GST ELISA. Because peptides are relatively expensive and recombinant proteins are simple and economical to produce, the latter may provide useful reagents for antibody detection in countries with endemic cysticercosis/NCC.

TSOL18/HP6-Tsol, an immunogenic Taenia solium oncospheral adhesion protein and potential protective antigen

“…Finally, as protection against Taenia spp. oncospheres is antibody mediated, logically therefore, any vaccine candidate may also serve as a diagnostic antigen, and our preliminary evidence shows that this is indeed the case for recombinant HP6-Tsag (TSA18; Fleury et al 2003;Ferrer et al 2003Ferrer et al , 2005Ferrer et al 2007.…”

Immunodiagnosis of Neurocysticercosis: Ways to Focus on the Challenge

“…For instance, from the members of the 8 kDa family, Ts18var1 has been produced in insect cells [16] as well as TsRs1, Ts18var1, and Ts18 Var3 [20]; the 14 and 18 kDa proteins produced by recombination [27]; Ts14, Ts18var1, TSRS1, and TSRS2var1 by chemical synthesis [29], and full-length Ts18 and Ts14 by chemical ligation [19], Ag1V1/Ag2 by recombination [26] as well as Ts8B1, Ts8B2, Ts8B3 [18], Ts14 [27] and a 10 kDa protein [17, 25]; GP50, which is not a member of the 8 kDa family but it is part of the LLGPs, was produced by recombination in bacteria and in a baculovirus expression system [16, 21]. Other proteins outside those from LLGPs that have also been produced or synthesized include T24 (integral membrane protein that does not bind to lentil lectin) produced in a droshophila cell line [22]; HP6-Tsag (oncospheral adhesion protein of Taenia saginata ) in bacteria and baculovirus systems with similar specificities between the systems (93–95%), but higher sensitivity for the inactive cases by the baculovirus protein (48–64%) [95]; peptide NC-1 selected by phage-display [23]; peptides KETc12, 410, and 413 synthesized from a cDNA library of T. crassiceps [24], and recombinant TS24 and Es33 [28]. The methods of production are varied, as well as the results and the ways to evaluate the produced protein, some giving very good sensitivities but in other cases, the native protein is much better than the produced one.…”

Taeniosis and Cysticercosis

“…Paramyosin, sHSP, TSA18, F18, 50 kDa glycoprotein, TsAg5, and other molecules were cloned and expressed in prokaryotic and eukaryotic systems and evaluated with collections of serum and CSF samples. The recombinant products have been checked in ELISA and Western blot, with good sensitivity and specificity for NCC diagnosis (Vazquez-Talavera et al 2001;Ferrer et al 2003bFerrer et al , 2005aFerrer et al , 2007aMontero et al 2003;Hancock et al 2004). Even though most of them worked better with active NCC samples, TSA18 expressed in baculovirus system showed the best sensitivity (60 %) for inactive NCC immunodetection.…”