The Preliminary Study On The Effect Of Sphingosine1-phosphate On Neutrophils’Function And The Signaling Pathway Involved

This current paper used S1P as priming reagent to study the influence of S1P on neutrophils and the signal pathway based on the influence of S1P on the activation of human neutrophils isolated from peripheral blood.Neutrophils, also named polymorphonuclear neutrophil (PMN), are key components of the first line of defense against bacterial and fungal pathogens. They contribute to the early innate response by rapidly migrating to inflamed tissues, where their activation triggers sterilization mechanisms such as rapid production of reactive oxygen species (ROS) in what is called the oxidative burst. ROS are strongly anti-microbial but which may also cause damage by destructing surrounding tissue and inducing apoptosis in other immune reactive cells.Respiratory burst activity of neutrophils is essential for the elimination of invading microorganisms. Reduced respiratory burst activity has been associated with impaired ability to kill bacteria and increased susceptibility to infectious diseases. The experiment described flow cytometric methods for the evaluation of newly isolated neutrophils and the expression of CD11b on no activated or activated PMN; Indirectly measuring O2-output by cytochrome C reduction in respiratory burst; Using Dihydrorhodamine123(DHR) to detect the intensity of respiratory burst; And detecting the expression of S1PR by RT-PCR. Our results showed that the state of newly isolated neutrophils were good and the influence of S1P on CD11b was not significant; After pretreated with SIP, the production of O2-released by fMLP-activated neutrophils significantly increased, and the Rhodamine123MFI of SIP primed fMLP-activated neutrophils group was significantly higher than fMLP treatment group;How SIP influences PMN becomes an interesting subject with the intensive study on how SIP influences immune system. RT-PCR analysis indicated that PMN expressed S1P receptors1,4,5, S1P receptor2and3only express on few of PMN. After looking up to generous of references, we suppose that there may be one or other pathways included. Western Blot experiment confirmed that SIP induced phosphorylation variation of signal protein protein kinase B (Akt), and further affects the respiratory burst of PMN. Results that S1P influenced on the function of PMN can provide theoretical basis and new theoretical pathway for cell therapy of tissues damage and TRALI caused by PMN inflammation and chemical therapy of immune inhibitors such as S1P analog.