Program / Abstract Book - KMU WWW3 Server for Education ...

No. 31 (PI 5)
Impact of interleukin-29 on interferon alpha secretion of plasmacytoid dendritic cell
Chi Hyun Cho, M.D. 1 , Chae Seung Lim, M.D. and Yun Jung Cho, M.D. 1*
1 Department of Laboratory Medicine, College of Medicine, Korea University, Seoul, Korea
Background: The alpha-IFN secretion by plasmacytoid dendritic cell was distinguished by rapid
kinetics, high level (up to 1000 fold higher than most cells), while the plasmacytoid dendritic cells
responded with vigorous alpha-IFN production to stimulation by a variety of viral stimuli and to
synthetic Toll-like receptor agonists. IL-28Rα (type III IFN receptor chain) signaling was demonstrated
not to provide feedback on type I expression in mouse study. In this study, we tried to identify whether
the type III IFN provides feedback or does not do so on alpha-IFN secretion of human plasmacytoid
dendritic cell.
Methods: From eleven healthy donors, 3 ml and 10 ml of whole blood were collected for complete
blood cell count by Coulter automatic analyzer and for the isolation of peripheral blood mononuclear
cells (PBMC). Plasmacytoid dendritic cell was counted by multiplying % of total PBMC
(flowcytometer) by mononuclear cells of whole blood (Coulter automatic analyzer). PBMC from each
healthy donor was then divided into four groups as follows: group 1- control; group 2- addition of CpG
DNA; group 3- addition of IL-29; group 4- addition of CpG DNA and IL29. Then, the culture media
were incubated for 24 hours at 37℃. The supernatants were collected and tested for the amount of
IFN-alpha secretion by the flowcytometer.
Results: The number of plasmacytoid dendritic cells (/µL) was 5.29 (±3.05). IFN-alpha (pg/ml)/pDC
(/µL) in each group was as follows: 5.677 (±9.278) in group 1; 1071.546 (±1026.598) in group 2;
14.142 (±21.107) in group 3; 1913.897 (±1525.928) in group 4. There were statistically significant
differences between group 1 vs 2 and group 2 vs 4, whereas there was no statistically significant
difference between group 1 vs 3. The addition of CpG DNA with IL-29 caused human pDC to secret
IFN-alpha about two times more than addition of CpG DNA alone.
Conclusions: Apart from mouse study, one of lambda-IFNs, IL-29 provided feedback on IFN-alpha
expression of human pDC. IL-29 alone did not have impact on IFN-alpha secretion by human pDC, but
with CpG DNA, had synergistic effect on that. Given the knowledge that IL-29 is potential therapeutic
alternatives to type I IFNs in terms of viral infections and tumors, this result could help elucidate the
mechanism of the therapeutic effect by IL-29.
Key Words : CpG DNA, IL-29, IFN-alpha, plasmacytoid dendritic cell
- 84 -