AUTHOR=Wu Yu-jing , Chen Heng-shi , Chen Wen-sheng , Dong Jin , Dong Xiao-jie , Dai Xing , Huang Qiong , Wei Wei TITLE=CP-25 Attenuates the Activation of CD4+ T Cells Stimulated with Immunoglobulin D in Human JOURNAL=Frontiers in Pharmacology VOLUME=9 YEAR=2018 URL=https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2018.00004 DOI=10.3389/fphar.2018.00004 ISSN=1663-9812 ABSTRACT=

Researchers have shown that the level of immunoglobulin D (IgD) is often elevated in patients with autoimmune diseases. The possible roles of IgD on the function of human T cell activation are still unclear. Paeoniflorin-6′-O-benzene sulfonate (code: CP-25), the chemistry structural modifications of paeoniflorin, was a novel drug of anti-inflammation and immunomodulation. The aims of this study were to determine if human CD4+ T cells could be activated by IgD via the IgD receptor (IgDR)-Lck pathway and whether the novel compound CP-25 could affect the activation of T cells by regulating Lck. Human CD4+ T cells were purified from peripheral blood mononuclear cells using microbeads. T cell viability and proliferation were detected by Cell Counting Kit-8 and CFSE Cell Proliferation Kit. Cytokines secreted by T cells were assessed with the Quantibody Human Inflammation Array. The binding affinity and expression of IgDR on T cells were detected by flow cytometry, and protein expression of IgDR, Lck, and P-Lck were analyzed by western blot. IgD was shown to bind to IgDR on CD4+ T cells in a concentration-dependent manner and stimulate the activation and proliferation of these cells by enhancing phosphorylation of the activating tyrosine residue of Lck (Tyr394). CP-25 inhibited the IgD-stimulated activation and proliferation of CD4+ T cells, as well as the production of inflammatory cytokines; it was thus suggested that this process might be related to the downregulation of Lck (Tyr394) phosphorylation. These results demonstrate that IgD amplifies the activation of CD4+ T cells, which could be mediated by Lck phosphorylation. Further, CP-25, via its ability to modulate Lck, is a novel potential therapeutic agent for the treatment of human autoimmune diseases.