牙龈卟啉单胞菌rag位点基因分型与细菌毒力的关系研究

目的：探讨牙龈卟啉单胞菌rag位点基因分型与细菌毒性的关系。方法将不同rag基因位点的牙龈卟啉单胞菌W83(rag-1型)、A011/9(rag-2型)、QM220(rag-3型)和ATCC33277(rag-4型)菌株分别刺激中性多形核白细胞,未受刺激的中性多形核白细胞作为对照。采用RT-PCR检测FcγⅢb受体基因,流式细胞术检测中性多形核白细胞凋亡情况,试剂盒检测毒力因子。结果 W83组 FcγⅢb基因相对表达量显著高于其他组( P <0．05),其次为QM220组,显著高于A011/9和ATCC33277组(P<0.05)。流式细胞术检测发现,ATCC33277组细胞凋亡率显著高于其他各组(P<0.05),A011/9组凋亡率显著高于W83组(P<0.05)。各基因分型组LPS、LBP、mCD14、MMP-8 MMP-9、IL-8以及IL-1β均高于对照组(P<0.05)。W83组上述指标显著高于其他各基因型组(P<0.05),QM220组次之,与 A011/9、ATCC33277组比较差异有统计学意义(P <0.05)。 A011/9组在 LPS、LBP、mCD14方面高于ATCC33277组(P<0.05),而MMP-8、MMP-9两者差异无统计学意义(P>0.05)。结论牙龈卟啉单胞菌菌株中rag位点基因分型的细菌毒性rag-1型最强,rag-3型次之,较弱的为rag-2型和rag-4型。

The relationship between the rag locus genotype of Porphyromonas gingivalis and bacterial virulence

Objective To investigate the relationship between the Porphyromonas gingivalis ( P. g ) rag genotype and the bacterial toxicity. Methods The P. g of different rag locus strains W83 (rag-1), A011/9 (rag-2), QM220 (rag-3) and ATC33277(rag-4) stimulated polymorphonuclear leukocyte (PMN), and un-stimulated PMN served as control. FcγⅢ b receptor gene was detected by RT-PCR and PMN apoptosis by flow cytometry. Results The expression of FcγⅢb in W83 group was significantly higher than that in other groups (P<0. 05), followed by QM220 group, and A011/9 and ATC33277 expressed the least (P<0. 05). The apoptosis rate of ATCC33277 group was significantly higher than other groups (P<0. 05), and the apoptosis rate of A011/9 group was significantly higher than that of group W83 (P<0. 05). LPS, LBP, mCD14, MMP-9, MMP-8, IL-8 and IL-1 of each genotype group were higher than those of control group (P<0. 05). Conclusion The bacterial virulence of strain rag-1 was the strongest, followed by rag-3, and rag-2 and rag-4 was the weakest.