Mechanisms by which Lactoferrin-derived chimeric peptide (LFch) enhances TGFβ1-induced Treg Differentiation

---

Presentation Time: 11:30 AM - 12:45 PM
Poster Board Number: B731
Abstract ID: 4762

Presenting Author:
Pyeung-Hyeun Kim , professor at Kangwon Natl. Univ., Kangwon Natl. Univ.

Abstract:

We recently reported that LF substantially promoted Foxp3 expression by activated CD4⁺T cells and this activity was further enhanced by TGF-β1. We also found that the lactoferrin chimera (LFch, synthetic LF-derived chimeric peptides) dramatically enhanced TGFβ1-induced Foxp3 expression, although LFch itself did not stimulate Foxp3 expression. In the present study, we explored the mechanism by which LFch boosts TGFβ1-induced Treg differentiation. We applied biotinylated LFch (LFch-biotin) to elucidate this issue. Through the receptor ELISA and co-immunoprecipitation experiments, we observed that LFch-biotin directly binds to TβRIII and PI3K. Further, it also binds and diminishes phosphorylated-PI3K which is associated with CD28. As expected, LFch-biotin boosted TGFβ1-induced Foxp3 expression. The same was true when PI3K inhibitor was treated. Taken together, these results suggest that LFch upregulates TGFβ1-induced Treg differentiation by diminishing CD28 signal intensity through the complex of LFch/TβRIII/PI3K/CD28.