RESUMEN
Ts8B2 is a gene which encodes for a member of the Taenia solium metacestode 8kDa antigen family. Since the Ts8B2-GST recombinant protein compares very favourably with other diagnostic antigens, and in order to study the antigenic nature and structure of this molecule, the Ts8B2 was expressed in prokaryotic and eukaryotic systems. The diagnostic potential of the recombinant Ts8B2 proteins was evaluated by enzyme-linked immunosorbent assays (ELISA) using a collection of serum and cerebrospinal fluid (CSF) samples from patients with clinically defined neurocysticercosis (NCC), and also sera from T. solium infected pigs. Despite the predicted glycosylation of the Ts8B2-Bac recombinant protein, there was very little difference in assay sensitivity/specificity when the Ts8B2 reagent was expressed in either prokaryotic or eukaryotic systems, suggesting that peptidic Ts8B2 epitopes are immunodominant in porcine cysticercosis and human neurocysticercosis. Conveniently, production of recombinant Ts8B2 in Escherichia coli is economical and facile, making it a feasible and practical choice as a diagnostic reagent for use in endemic areas. The Ts8B2 ELISA is particularly useful for the diagnosis of active as opposed to inactive cases of NCC and conduct of the assay is also facilitated by the fact that assay sensitivity is significantly greater when serum as opposed to CSF samples are employed.
Asunto(s)
Antígenos Helmínticos/inmunología , Cisticercosis/diagnóstico , Cisticercosis/veterinaria , Epítopos Inmunodominantes/inmunología , Taenia solium/inmunología , Animales , Anticuerpos Antihelmínticos/sangre , Anticuerpos Antihelmínticos/líquido cefalorraquídeo , Antígenos Helmínticos/genética , Baculoviridae/genética , Línea Celular , Cisticercosis/inmunología , ADN de Helmintos/química , ADN de Helmintos/genética , Ensayo de Inmunoadsorción Enzimática/métodos , Escherichia coli/genética , Expresión Génica , Humanos , Epítopos Inmunodominantes/genética , Datos de Secuencia Molecular , Proteínas Recombinantes/genética , Proteínas Recombinantes/inmunología , Sensibilidad y Especificidad , Análisis de Secuencia de ADN , Spodoptera , PorcinosRESUMEN
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.
