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Mediators of Inflammation
Volume 2016 (2016), Article ID 4328372, 8 pages
Research Article

Increased IL-21 Expression Induces Granzyme B in Peripheral CD5+ B Cells as a Potential Counter-Regulatory Effect in Primary Sjögren’s Syndrome

Division of Clinical Immunology, Faculty of Medicine, University of Debrecen, Móricz Zsigmond Street 22, Debrecen 4032, Hungary

Received 2 October 2015; Revised 3 December 2015; Accepted 16 December 2015

Academic Editor: Teresa Zelante

Copyright © 2016 Gábor Papp et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Recently, we reported elevated proportions of circulating follicular T helper cells and higher levels of interleukin- (IL-) 21 in primary Sjögren’s syndrome (pSS). Interaction of invariant natural killer T (iNKT) cells with B cells and granzyme B (GrB) production may be also important in pSS. Thirty-two pSS patients and 24 healthy controls were enrolled in our study. We investigated the expression of intracellular GrB and IL-21 receptor (IL-21R) of CD19+CD5+ and CD19+CD5 B cells; furthermore, we determined the IL-21 expression of iNKT cells as well. We also assessed the proportion of transitional (), mature () and primarily memory () B cells. CD5+ but not CD5 B cells showed elevated GrB and IL-21R expression in pSS; additionally IL-21 expression of iNKT cells was also elevated. The ratios of transitional and mature B cells were elevated in pSS, while primarily memory B cell percentages were decreased, which correlated with GrB and IL-21R expression of CD19+ B cells. Our results suggest that enhanced IL-21R expression of CD19+CD5+ B cells and production of IL-21 by iNKT cells may play an important role in the pathogenesis of pSS by regulating CD19+CD5+ B cell functions and increasing GrB production, presumably leading to a counter-regulatory effect in the disease.