B7-1、B7-2在牙龈卟啉单胞菌脂多糖诱导的T淋巴细胞反应中的作用

目的：研究B7?1、B7?2分子对牙龈卟啉单胞菌（ Porphyromonas gingivalis，P． g）脂多糖诱导的T淋巴细胞反应的影响。方法：分别从基因敲除小鼠（ B7?1 KO组、B7?2 KO组、B7?1／2 KO组）和野生小鼠（ WT组）骨髓培养获得原代树突状细胞（ dendritic cell，DCs）并经P． g脂多糖刺激后，与T细胞混合培养。 CCK8试剂盒评价T细胞增殖，ELISA检测培养液中IFN?γ、IL?4及IL?17的水平，荧光定量PCR检测T细胞IFN?γ、IL?4、IL?17、GATA?3、T?bet及RORγt的转录水平。结果：CCK8检测显示各组T细胞增殖水平无差异。 ELISA及荧光定量PCR显示与WT组比较，B7?1 KO组IFN?γ降低，IL?4升高，IL?17无变化，T?bet降低，GATA?3升高，RORγt无变化；B7?2 KO组IFN?γ升高，IL?4降低，IL?17降低，T?bet升高，GATA?3降低，RORγt降低；B7?1／2 KO组各因子变化趋势介于B7?1 KO组和B7?2 KO组之间。结论：B7?1及B7?2分子对P． g脂多糖刺激的T细胞增殖无明显影响。但B7?1分子可促进T细胞向Th1型分化，抑制Th2型分化，与Th17型分化相关性不大；而B7?2分子抑制T细胞向Th1型分化，促进Th2型及Th17型分化。

Effect of B7-1 and B7-2 on T lymphocyte response induced by lipopolysaccharide of Porphyromonas gingivalis

Objective:To investigate the effect of B7?1 and B7?2 on T lymphocyte response induced by lipopolysac?charide( LPS) of Porphyromonas gingivalis( P. g) . Methods:Dendritic cells( DCs) were cultured from the bone marrow of B7?1 KO,B7?2 KO,B7?1/2 KO and wild type( WT) mice. DCs were stimulated with LPS of P. g. in advance and then co?cul?tured with T lymphocytes. CCK8 kit was used to examine the proliferation of T lymphocytes. Cytokines such as IFN?γ,IL?4 and IL?17 in the supernatants were detected by ELISA. Quantitative real?time PCR( qPCR) was performed to test the RNA levels of IFN?γ,IL?4,IL?17,GATA?3,T?bet and RORγt of T cells. Results:There was no significant difference in T cell pro?liferation among groups. Compared with WT group,B7?1 KO group showed decreased IFN?γ and T?bet,increased IL?4 and GATA?3,and similar levels of IL?17 and RORγt. Whereas,B7?2 KO group showed higher levels of IFN?γ and T?bet,and lower levels of IL?4,GATA?3,IL?17 and RORγt than WT group. The variation tendency of these factors in B7?1/2 KO group was between those of B7?1 KO group and B7?2 KO group. Conclusion:Deficency of B7?1 and/or B7?2 in DCs does not in?fluence DCs?induced T lymphocyte proliferation. B7?1 may promote T lymphocyte differentiation to Th1 cells,inhibit its dif?ferentiation to Th2 cells,While B7?2 may inhibit T lymphocyte differentiation to Th1 cells and promote its differentiation to Th2 and Th17 cells.