ObjectiveTo study the proliferation of CRTH2 (CD4+CD294+Th2) cells promoted by pneumococcal vaccine through antigen presentation of dendritic cells (DCs), so as to provide a new approach for amplification and sorting of Th2 cells. MethodsCDs induced from peripheral blood mononuclear cells were cocultured with T lymphocytes after loading pneumococcal vaccine antigen, mixed lymphocyte reaction (MLR) was detected by cell counting kit8(CCK8), DCs and CRTH2 cells were analyzed by flow cytometry. ResultsPneumococcal vaccine could promote the maturation of DCs, together with TNFa, it was adjuvant for maturation of DCs. Pneumococcal vaccine antigenloaded DCs could increase the rate of subsets of CRTH2 cells on day 5(［0.93±0.10］%) compared with day 1(［0.70±0.02］%), and absolute number also increased (both P<0.05). ConclusionAmplification of CRTH2 cells can be greatly promoted by pneumococcal vaccine antigenloaded DCs, which might be one of the effective way to induce amplification of Th2 cells.