Open AccessIL-28B Genetic Variants Determine the Extent of Monocyte-Induced Activation of NK Cells in Hepatitis C
Author(s) -
Benjamin Krämer,
Claudia Finnemann,
Beatriz Sastre,
Philipp Lutz,
A Glässner,
F Wolter,
Felix Goeser,
P Kokordelis,
Dominik J. Kaczmarek,
Hans Dieter Nischalke,
Christian P. Strassburg,
Ulrich Spengler,
Jacob Nattermann
Publication year - 2016
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0162068
Subject(s) - genotype , interleukin 12 , immunology , interleukin 21 , peripheral blood mononuclear cell , biology , secretion , monocyte , microbiology and biotechnology , t cell , cytotoxic t cell , immune system , gene , endocrinology , genetics , in vitro
Background Immuno-genetic studies suggest a functional link between NK cells and λ-IFNs. We recently showed that NK cells are negative for the IFN-λ receptor IFN-λR1 and do not respond to IFN-λ, suggesting a rather indirect association between IL-28B genotype and NK cell activity. Methods A total of 75 HCV(+) patients and 67 healthy controls were enrolled into this study. IL-28B (rs12979860) and IFNL-4 (rs368234815) genotypes were determined by rtPCR. Total PBMC, monocytes, and NK cells were stimulated with IL-29, the TLR-7/8 agonist R848, or a combination of both. NK cell IFN-γ response was analysed by FACS. IL-12 and IL-18 secretion of monocytes was studied by ELISA. In blocking experiments anti-IL-12/anti-IL-18 were used. Results Following stimulation of total PBMCs with R848 we found NK cell IFN- γ responses to vary with the IL-28B genotype, with carriers of a T/T genotype displaying the lowest frequency of IFN-γ(+)NK cells. When isolated NK cells were studied no such associations were observed, indicating an indirect association between IL-28B genotype and NK cell activity. Accordingly, we found R848-stimulated monocytes of patients with a T/T genotype to be significantly less effective in triggering NK cell IFN- γ production than monocytes from carriers of a non-T/T genotype. In line with these findings we observed monocytes from T/T patients to secrete significantly lower concentrations of IL-12 than monocytes from non-T/T individuals. Conclusions Our data indicate that monocytes from carriers of an IL-28B T/T genotype display a reduced ability to stimulate NK cell activity and, thus, provide a link between IL-28B genotype and NK functions.