Abstract: ［Abstract］ Objective〖HTSS〗〓To dissect the role of calcitonin gene related peptide(CGRP) on IL17 producing T cell(Th17) and regulatory T cell(Treg) differentiation.
〖HTH〗〖WTHZ〗Methods〖HTSS〗〓Naive CD4+T cells were isolated from human peripheral blood by magnetic activated cell sorting(MACS) selection, and cultured under Th17polarizing and Tregpolarizing condition, The proportion of Th17 cells and Treg cells were detected by flow cytometry, the relative expression levels of retionidrelated orphan nuclear receptor γt(RORγt) mRNA and foxhead box protein 3(FoxP3) mRNA were measured by realtime RTPCR. In addition, we detected the production of IL17A by enzymelinked immunosorbent assay, we explored the effects of CGRP on the differentiation of Th17 and Treg cells form Several aspects.
〖HTH〗〖WTHZ〗Results〖HTSS〗〓CGRP increased the proportion of Th17 cells and the expression of RORγt mRNA(P＜005). Additionally, CGRP also increased the production of IL17A(P＜005), these effects of CGRP were in dosedependent manner. Meanwhile, CGRP inhibited the percentage of Treg cells and the expression of FoxP3 mRNA also in dosedependent way(P＜005), peaking at 10-6 M.
〖HTH〗〖WTHZ〗Conclusion〖HTSS〗〓These results demonstrate that CGRP facilitates naive CD4+T cells from human peripheral blood differentiate to Th17 cells, but suppresses them differentiate to Treg cells.

Key words: calcitonin, Th17 cells ；Tlymphocytes, regulatory