脾脏巨噬细胞对凋亡细胞诱导免疫反应的影响

The effect of splenic macrophage on immune response induced by apoptotic cell

为研究小鼠脾脏巨噬细胞(Mφ)对凋亡细胞诱导免疫应答的影响,我们用氯磷酸二钠脂质体(clodronate-liposomes,CL)清除小鼠脾脏Mφ,于不同时间点对三组(nave、PBSL、CL)小鼠选择性回输e450标记的DO11.10CD4^+T细胞、凋亡细胞及其相关抗原,然后用流式细胞仪检测小鼠血液与脾脏中免疫细胞的清除率、DO11.10CD4^+T细胞(即KJ126+T细胞)的增殖及Foxp3+Treg细胞的增殖。结果显示:(1)注射CL 1d后,外周血单核细胞的清除率约93%,脾脏中F4/80+Mφ、单核细胞与树突细胞的清除率分别为99%、90%、54%;(2)PBSL组与CL组中,KJ126+T细胞占CD4+T细胞的比率分别为1.32%、0.56%,差异有统计学意义(P<0.0001);Foxp3+T细胞占CD4^+T细胞的比率分别为0.69%、0.89%,差异有统计学意义(P=0.0004)。表明CL可以有效清除血液与脾脏中的免疫细胞;清除脾脏Mφ可以抑制KJ126+T细胞的增殖和促进Foxp3+Treg细胞的增殖。提示脾脏Mφ参与了提呈凋亡细胞相关抗原的过程,参与调节凋亡细胞诱导的抗原特异性T细胞的免疫应答能力及凋亡细胞诱导的免疫耐受。说明脾脏Mφ在凋亡细胞诱导的免疫反应中起着重要的作用。

To study the effect of splenic macrophage in mice on apoptotic cell-induc-ed immune response, we deplete splenic macrophage with clodronate- liposomes（CL）, three groups mice （Naive, PBSL, CL） were selectively injected e450-1abeled DO11. 10CD4^＋ T cells, apoptotic cells and apoptotic cell-associated antigens at different time points, then immune cells eradication rate in blood and spleen,proliferation of DO11. 10 CD4^＋ T cells （KJ126^＋ T cells） and regulatory T cells （Foxp3^＋ Treg） were measured by flow cytometry. Results showed that： （1） CL administration 1 day later, CL reduced monocyte numbers in peripheral blood by 93%, splenic F4/80^＋ Mφ,monocyte and DC numbers by 99%,90% and 54% respectively. （2） In CL and PBSL, KJ126^＋T cell ratio of CD4^＋T ceils were 0. 56%, 1. 32%, the difference was statistically significant, P〈0. 0001; Foxp3^＋T cells of CD4^＋T cells were 0.89%,0.69%, theratio of difference was statistically significant, P= 0. 0015. It was showed that CL can effectively remove the immune cells in blood and spleen; The depletion of splenic macrophages can inhibit the proliferation of KJ126^＋ T cells but promote the proliferation of Foxp3^＋ Treg. These results suggested the involvement of splenic macrophages in apoptotic cell-associated antigen presentation, splenic macrophage was involved in apoptotic cell-induced antigen specific T cell immune response and immune tolerance. To show that splenic rnacrophage play an important role in the immune response induced by apoptotic cells.