Development of a Fluorescent RBL Reporter System for Diagnosis of Porcine Cysticercosis

Abstract text

Introduction:

Porcine cysticercosis (PCC) is a World Organization for Animal Health listed notifiable disease, caused by the larval stage of Taenia solium. Pigs get infected by ingesting human stool or water/vegetation contaminated with T. solium eggs. The disease is endemic in Latin America, sub-Saharan Africa, South and South East Asia. PCC hampers food security and affects livelihoods of pig farmers resulting in reduced pork value and economic loss, especially in developing countries. Available serological diagnostic tests based on IgG detection are characterised by low specificity.

Objectives:

This study aims to assess suitability of detecting parasite-specific Immunoglobulin E (IgE) using species-specific IgE reporter cell lines. Our objectives are to create a reporter cell line that is able to bind pig IgE and to identify, clone, and recombinantly express candidate T. solium antigens, which will be assessed for their suitability as "diagnostic allergens" for diagnosis of PCC.

Materials and methods:

We used pcDNA5 as vector backbone for cloning of a synthetic pig high affinity IgE receptor alpha chain (SsFCERIA). After ligation and bacterial transformation, we transfected our target transformant (SsFCERIA/pcDNA5) into RBL NPY-mRFP reporter system to develop "porcinised" reporter system (RBL NPY-mRFP SsFCERIA) and for further selection of stable transfectant cell lines. We selected 10 predicted allergens of T. solium (Q9NI46, Q2XNL7, K0A0S9, E5LBB8, A3F4Q9, A3F4W9, A3F4U5, A3F4Y2, A3F4V0, and A3F4Y4) for further bioinformatic analysis.

Results:

From bioinformatic analysis, we found a signal peptide in one allergen, N-linked glycosylation site in 4, and different protein motifs (e.g. FABP, EF-Hand 1, and Trypsin-like), but no transmembrane regions. The corresponding cDNAs will be used for recombinant expression using HEK293-6E cells grown in suspension.

Conclusion:

Our study will enable development of a novel diagnostic tool to improve the standard of current serological diagnosis of PCC, which may help to interrupt zoonotic transmission of T. solium in endemic countries.