Molecular Characterization and Diagnostic Value of Taenia solium Low-Molecular-Weight Antigen Genes

Abstract

Neurocysticercosis (NCC) caused by infection with the larvae ofTaenia solium is an important cause of neurological disease worldwide. In order to establish an enzyme-linked immunosorbent assay (ELISA) for this infection using recombinant proteins, we carried out molecular cloning and identified four candidates as diagnostic antigens (designated Ag1, Ag1V1, Ag2, and Ag2V1). Except for Ag2V1, these clones could encode a 7-kDa polypeptide, and Ag2V1 could encode a 10-kDa polypeptide. All of the clones were very similar. Except for Ag2V1, recombinant proteins were successfully expressed using anEscherichia coli expression system. Immunoblot analysis of NCC patient sera detected recombinant proteins, but because reactivity to recombinant Ag1 was too weak, Ag1 was not suitable as an immunodiagnostic antigen. So, Ag1V1 and Ag2 were chosen as ELISA antigens, and the Ag1V1/Ag2 chimeric protein was expressed. Of 49 serum samples from NCC patients confirmed to be seropositive by immunoblot analysis, 44 (89.7%) were positive by ELISA. No assays of serum samples from patients with other parasitic infections recognized the Ag1V1/Ag2 chimeric protein. The Ag1V1/Ag2 chimeric protein obtained in this study had a high value for differential immunodiagnosis.

Taeniasis in Mongolia, 2002–2006

“…There was no indication of T. solium cysticercosis by serology using both native T. solium glycoprotein antigens 4 and recombinant antigen. 6 In Mongolia, pigs are kept indoors, and pig owners (non-nomadic or seminomadic people ‫ס‬ settlement) use simple latrine facilities with little free access to pigs. Nobody had a habit of consuming uncooked or undercooked pork.…”

“…For a total of 73 serum samples including 14 serum samples from people with histories of epileptic seizures, enzyme-linked immunosorbent assay (ELISA) and immunoblot were carried out using glycoproteins (GPs) purified by preparative isoelectric focusing from T. solium cyst fluids 4,5 and a recombinant chimeric T. solium antigen. 6 These assays were performed at Asahikawa Medical College, Japan, in 2004 and 2006.…”

Identification and control of sources of Taenia solium infection – the attempts to eradicate the parasite

“…Research on antigenic features of surface proteins and cyst fluid and revised techniques of purification have resulted in the elaboration of improved serological applications. Nowadays, many scientists tend to use synthetic or recombinant proteins (7,38). It was shown that the specificity of these antigens is higher than that of native antigens; however, their sensitivity is predominantly lower (9).…”

Basic and applied problems in developmental biology and immunobiology of cestode infections: Hymenolepis,Taenia and Echinococcus

“…Lentil-lectin affinity-purified GPs (177) have specific components with lower molecular weights, which are useful for detection of cysticercosis cases by WB, but also include nonspecific components of higher molecular weights which affect ELISA results (Figures 4 and 5). Recombinant antigens (186) show better specificity than the lentil-lectin affinity-purified GPs (177) and similar sensitivity to native antigens purified by isoelectrophoresis (183,184) and cation-exchange chromatography (187). There continues to be some debate on the best way to serologically detect cysticercosis.…”

“…Western blot figures of cyst fluid of T. solium (a), lentillectin affinity-purified glycoproteins (GPs) (b) (177), two fractions of isoelectrofocusing purified GPs (c, d) (184) incubated with pooled pig sera confirmed infected with T. solium (panel a), with pooled NCC patients sera (panel b), and with a rabbit anti-A fraction GPs (c) by isoelectrofocusing (panel c)(184). Highly purified GPs isolated by isoelectrofocusing can be prepared by a very cheap cation-exchange chromatography(186).…”