CCR7(lo)PD-1(hi) CXCR5(+) CD4(+) T cells are positively correlated with levels of IL-21 in active and transitional cystic echinococcosis patients.

Fengbo Zhang,Yuejie Zhu,Jun Li,Jianbing Ding,Dexian Zhou,Hao Wen,Buka Samten,Jinwei Hu,Nannan Pang,Haining Fan,Xiumin Ma,Hui Zhao

doi:10.1186/s12879-015-1156-9

Abstract

BackgroundIn our study, we investigated whether circulating T follicular helper (Tfh) and the related cytokines are involved in human cystic echinococcosis (CE).MethodsA total of 64 patients with CE and 30 healthy controls were enrolled in this study. Percentages of CCR7loPD-1hi cells within CXCR5+ CD4+ T cells (circulating Tfh cells) were detected by flow cytometry. Levels of IL-21 and IL-4 in peripheral blood were detected by cytometric bead array. The mRNA expression of IL-21, IL-4, Bcl-6, and Blimp-1 in peripheral blood mononuclear cells (PBMCs) were measured by real-time PCR. Levels of IgG1, IgG2, IgG3, and IgG4 in the patients’ sera were measured using enzyme-linked immunosorbent assay.ResultsPercentages of circulating Tfh cells were significantly increased in the CE1, CE2, and CE3 groups (p < 0.05). The concentrations of IL-21 and IL-4 in the serum were significantly increased in CE1, CE2, and CE3 groups (p < 0.05). IL-21 was positively correlated with circulating Tfh cells in CE3 group (r = 0.779, p < 0.05). The mRNA levels of IL-21, IL-4, and Bcl-6 were increased in CE1, CE2, and CE3 groups. Levels of IgG1 and IgG4 in patients’ sera were increased in CE1, CE2, and CE3 groups. Levels of IgG2 and IgG3 were increased in CE4-5 group. Additionally, after stimulation with hydatid fluid in vitro, the levels of circulating Tfh cells, IL-21 and IL-4 in PBMCs isolated from CE patients were significantly increased (p < 0.05).ConclusionsThe levels of circulating Tfh and related cytokines were significantly increased in CE patients, suggesting that they are involved in human CE.Electronic supplementary materialThe online version of this article (doi:10.1186/s12879-015-1156-9) contains supplementary material, which is available to authorized users.

Highlights

In our study, we investigated whether circulating T follicular helper (Tfh) and the related cytokines are involved in human cystic echinococcosis (CE)
The frequency of CCR7loPD-1hi cells within CXCR5+ CD4+ T cells is increased in CE1, CE2, and CE3 groups To determine expression of CCR7loPD-1hi T cells in Peripheral blood mononuclear cells (PBMC) from CE patients, flow cytometry analysis was performed
Differences among CE1, CE2, and CE3 groups were not statistically significant. These results indicated that percentages of CCR7loPD-1hi cells within CXCR5+ CD4+ T cells are significantly higher in CE1, CE2, and CE3 group patients than in healthy controls

Summary

Introduction

We investigated whether circulating T follicular helper (Tfh) and the related cytokines are involved in human cystic echinococcosis (CE). The host immune responses to hydatid, especially antibody class switching, varies in different CE types. Activities of Th1 and Th2 cells are involved in the chronic infectious parasitic diseases [10, 11]. During the EG infection in humans, Th1 immune responses are dominant in the early stage of hydatid infection, and IL-2 and IFN-γ secreted by Th1 cells are directly related with the slow growth of hydatid. The Th2 immune responses become dominant in the advanced stages, associated with rapid growth of hydatid [13]. Th9 cells are involved in the immune responses against Eg-infection [15]. Relationship between the Eg-infection and the newly identified CD4+ T cells subgroup called follicular helper CD4+ T (Tfh) cells is not reported

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Conclusion