Date Published: November 17, 2015
Publisher: Public Library of Science
Author(s): Linda Petrone, Valentina Vanini, Elisa Petruccioli, Giuseppe Maria Ettorre, Vincenzo Schininà, Elisa Busi Rizzi, Alessandra Ludovisi, Angela Corpolongo, Giuseppe Ippolito, Edoardo Pozio, Antonella Teggi, Delia Goletti, Aysegul Taylan Ozkan. http://doi.org/10.1371/journal.pntd.0004209
Abstract: BackgroundCystic echinococcosis (CE) is a complex disease caused by Echinococcus granulosus (E.granulosus), and its immunophatogenesis is still not clearly defined. A peculiar feature of chronic CE is the coexistence of Th1 and Th2 responses. It has been suggested that Th1 cytokines are related to disease resistance, whereas Th2 cytokines are related to disease susceptibility and chronicity. The aim of this study was to evaluate, by multi-parametric flow cytometry (FACS), the presence of CE specific immune signatures.Methodology/Principal FindingsWe enrolled 54 subjects with suspected CE; 42 of them had a confirmed diagnosis, whereas 12 were classified as NO-CE. Based on the ultrasonography images, CE patients were further categorized as being in “active stages” (25) and “inactive stages” (17). The ability of CD4+ T-cells to produce IFN-γ, IL-2, TNF-α, Th2 cytokines or IL-10 was assessed by FACS on antigen-specific T-cells after overnight stimulation with Antigen B (AgB) of E.granulosus. Cytokine profiles were evaluated in all the enrolled subjects. The results show that none of the NO-CE subjects had a detectable AgB-specific response. Among the CE patients, the frequency and proportions of AgB-specific CD4+ T-cells producing IL-2+TNF-α+Th2+ or TNF-α+Th2+ were significantly increased in the “active stages” group compared to the “inactive stages” group. Moreover, an increased proportion of the total polyfunctional subsets, as triple-and double-functional CD4 T-cells, was found in CE patients with active disease. The response to the mitogen, used as a control stimulus to evaluate the immune competence status, was characterized by the same cytokine subsets in all the subjects enrolled, independent of CE.ConclusionsWe demonstrate, for the first time to our knowledge, that polyfunctional T-cell subsets as IL-2+TNF-α+Th2+ triple-positive and TNF-α+Th2+ double-positive specific T-cells associate with cyst biological activity. These results contribute to increase knowledge of CE immunophatogenesis and the disease outcome in terms of control and persistence.
Partial Text: Cystic echinococcosis (CE) is a widespread zoonosis caused by the larval stage of the tapeworm Echinococcus granulosus (E.granulosus) .
In this prospective study, we characterize, for the first time to our knowledge, the specific immune response to AgB of E.granulosus in patients with the active and inactive clinical forms of CE. We demonstrate that IL-2+TNF-α+Th2+ triple-positive AgB-specific CD4+ T-cells and TNF-α+Th2+ double-positive AgB-specific CD4+ T-cells associate with cyst biological activity, being significantly increased in the active CE stages. We also found an increased (but not significant) proportion of the total polyfunctional subsets in CE patients with active disease. Altogether, these results help to contribute to the knowledge of the CE immunophatogenesis, as well as the mechanisms associated with disease control and persistence. Moreover, comprehension of the pathways involved in host protection or parasite survival could help to find biomarkers for developing new tools for CE diagnosis and/or therapy monitoring.