The Effect Of Nicotine On The Differentiation Of T Lymphocyte

Objective: To observe the effect of Nicotine on the differentiation of T lymphocyte CD4+and CD8+subsets, and the change of the balance of Th1 and Th2 cells. Methods:(1) twenty of 6-8 weeks aged female BALB/C mice were divided into 4 groups randomly: control group,1.5mg group,3.0 mg group,6.0 mg group. Mice had been respectively hypodermic-injected with 0.9% Nacl or nicotine solution by kg body weight every day for 3 weeks. The splenical cells of mice were prepared through a stainless steel mesh and T lymphocytes were purified through a nylon wool column. Then T-cells were labeled with Thy-1-FITC Ab or CD4 -FITC Ab and CD8 -PE Ab. The purity of T lymphocytes and ratio of CD4+ cells and CD8+ cells were detected and analyzed by Flow Cytometry. (2)The concentration of IL-2, IL-4, IL-5, IFN-γand TNF-αin plasma could be determined by the Mouse Th1/Th2 Cytokine CBA kit.(3) Extract total RNA of T lymphocyte, amplify the particular strands of the five cytokines above by RT-PCR, then take agarose gel electrophoresis and analyze the data. Results:(1) The purity ratio of T lymphocytes was ranged from 78.53% to 83.66%,so the segregation ratio of T lymphocytes was about 80% by the method of The nylon wool column. The ratio of CD4+ cells and CD8+ cells of the test groups obviously decrease than that of the control group, P<0.05. Therefore nicotine could affect the differentiation of T lymphocyte CD4+and CD8+subsets,could decrease the ratio of CD4+ cells and CD8+ cells , moreover, the effect of high concentration nicotine was more significant.(2)The concentration of the five cytokines changed obviously in plasma after nicotine administration: IL-2 and TNF-αincreased, IL-4 and IL-5 decreased. IFN-γwas not detected. (3)RT-PCR suggested that nicotine could affect the expressing of the cytokines, and the experiment showed the expression of IL-4, IL-5, TNF-αdecreased, IL-2, IFN-γ increased in the test groups. Conclusions: Nicotine could decrease the ratio of CD4+ cells and CD8+ cells and decrease the expression of IL-4, IL-5, cytokines of Th2 cells, however, it seemed that nicotine could increase the expression of IL-2, IFN-γ, cytokines of Th1 cells. So nicotine could affect the balance of the Th1 and Th2 cells, could mainly inhibit Th2 cells and further inhibit Antibody-mediated immune response.