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Updated: Aug 7, 2026
Stimulation of Cytoplasmic DNA Sensing Pathways In Vitro and In Vivo
Published on: September 18, 2014
CpG oligodeoxynucleotide prolongs eosinophil survival through activation of contaminating B cells and plasmacytoid
Kenji Matsumoto1, Maki Terakawa, Shuhei Fukuda
1Department of Allergy and Immunology, National Research Institute for Child Health and Development, Tokyo, Japan. kmatsumoto@nch.go.jp
Background:
In our previous study, oligodeoxynucleotides containing unmethylated CpG motifs (CpG ODNs) significantly prolonged eosinophil survival without inducing active release of eosinophil-derived neurotoxin or interleukin 8. In addition, this survival-promoting activity was nuclear factor-kappaB dependent. However, some eosinophil preparations from different donors hardly responded to CpG ODNs at all. To clarify why CpG ODN-induced nuclear factor-kB activation in eosinophils does not cause eosinophil-derived neurotoxin or interleukin 8 release and why the survival-promoting activity of CpG ODNs was not found in some eosinophil preparations, we determined the effect of extensive removal of contaminating B cells and plasmacytoid dendritic cells from human eosinophil preparations.
Methods:
Eosinophils were purified from the peripheral blood of healthy or slightly allergic donors by gradient sedimentation and negative selection with anti-CD16 alone or a combination of anti-CD16, anti-CD19 and anti-blood dendritic cell antigen 4 (BDCA4) immunomagnetic beads. Eosinophil survival was measured with FITC-conjugated annexin V and propidium iodide by FACS after incubation with synthetic CpG 2006(CpG-B), CpG 2216 (CpG-A) or their GpC control ODNs for 24 h.
Results:
The addition of anti-CD19 and anti-BDCA4 immunomagnetic beads reduced the number of contaminating CD19+ cells and CD123+ BDCA2+ cells in eosinophil preparations. CpG 2006 and CpG 2216, but not their GpC control ODNs, significantly prolonged survival of eosinophils purified with anti-CD16 immunomagnetic beads alone but not eosinophils purified with a combination of anti-CD16, anti-CD19 and anti-BDCA4 beads.
Conclusions:
These results strongly suggest that contaminating B cells or plasmacytoid dendritic cells in eosinophil preparations critically regulate CpG ODN-mediated prolongation of eosinophil survival and that CpG ODNs do not activate eosinophils directly.
