Inflammatory CD8+ T Cells Are Reduced by Applying FTY-720 to Activate Sphingosine-1-Phosphate Receptor Signaling

Abstract

Biomaterials generally induce a natural inflammatory response which can be altered by adding molecules to influence immune cell recruitment. Sphingosine-1-phosphatase (S1P) is a biological signaling lipid which performs the function of immunity regulation and controls the transportation of immune cells through the blood and body tissues. There are five S1P receptors (S1PRs), in which case are all G-protein coupled receptors that attach to and mediate most of the functions that the S1P performs. FTY720 is an agonist of 4 out of the 5 S1PRs and is known as immunomodulatory compound due to its ability to control the trafficking of immune cells. Biomaterial loaded with FTY720 were implanted into the injury skin of mice. Flow cytometry was used to analyze T-cell population in the digested tissues. This study shows that the application of FTY720, reduces inflammatory CD8+ T-cells by using a localized presentation of S1P which also shows how S1P signaling affects the distribution of harmful and helpful T-cells after injury. For the successful application of S1P in a localized tissue, it is important to consider the possible effects of its interaction with the environment. In an injury, with high levels of CD8+ T cells have been shown to block healing by increasing inflammatory cytokines (Reinke et al., 2013). In our study showed that local FTY720 reduces inflammatory CD8+ T-cells that helps the early anti-inflammation healing environment.