ENHANCEMENT OF GROWTH OF PERIODONTOPATHIC BACTERIA BY PRO-INFLAMMATORY CYTOKINES

(1)细胞因子对细菌生长的影响：我们研究了IL-α、β和IL-6对细菌生长的影响。在放线杆菌生长的对数阶段(9h：1.6-1.9倍，18：1.5-1.7倍)，观察到IL-1α、β对放线杆菌生长的促进作用。IL-1α浓度为1~100 ng/ml时，与对照组相比，9h后可促进放线杆菌的生长。10和100 ng/ml的IL-1β可促进放线杆菌生长。(2)IL-1α、β和IL-6与细菌的结合：放线杆菌对放射性标记的IL-1α、β和IL-6的摄取水平较高，而Capnocytophaga和梭杆菌结合的量很低。(3)人细胞因子受体基因同源性搜索：当我们检测细菌细胞因子受体基因表达时，只在放线杆菌中检测到IL-IR(I)和IL-IR(II)的表达，而其他细菌如卟啉单胞菌、普雷沃特氏菌、梭杆菌和吞噬细胞都没有检测到IL-IR(I)和IL-IR(II)的表达。另一方面，IL-6R在所有菌株中均未检测到表达。(4)自分泌抗菌机制：检测细菌培养上清液中IL-Iα、β和IL-6细胞因子活性。梭杆菌和吞噬毛细胞中有少量的IL-1α活性，但差异不显著。在所有使用的菌株中都检测到微量的IL-Iβ，特别是在放线杆菌中检测到较高水平的IL-Iβ。并不是所有菌株都能产生IL-6。

(1) Effect of cytokines on bacteria growth : we investigated the effect of IL-alpha, beta and IL-6 on bacterial growth. The growth-promoting effect of IL-1alpha, beta over control (no IL-1) was observed during the log phase of Actinobacillus growth (9h : 1.6-1.9 times, 18th : 1.5-1.7 times) . IL-1 alpha at 1 to 100 ng/ml enhanced Actinobacillus growth after 9h incubation compared to control. IL-1beta at 10 and 100 ng/ml promoted Actinobacillus growth. IL-1 alpha, beta also had a smaller effect on Capnocytophaga and Fusobacterium growth.(2) Binding of ^<125>I-IL-1alpha, beta and IL-6 to bacteria : Actinobacillus showed a high level of uptake of the radiolabeled IL-1alpha, beta and IL-6, While Capnocytophaga and Fusobacterium bound a very low amount of ^<125>I-IL-1alpha and IL-6. Other strains including Porphyromonas, Prevotella and Eikenella did not bind to cytokines.(3) Homology search with human cytokine receptor gene : When we examined bacteria for gene expression of cytokine receptor, expression of IL-IR (I) and IL-IR (II) was only detected in Actinobacillus, not other bacteria such as Porphyromonas, Prevotella, Fusobacterium and Capnocytophaga. On the other hand, IL-6R expression was not detected in all the strains used.(4) Autocrine mechanism against bacteria : We examined IL-Ialpha, beta and IL-6 cytokine activity in bacterial culture supernatants. IL-1alpha activity was detected slightly in Fusobacterium and Capnocytophaga, but was not significant. Trace amounts of IL-I beta ware detected in all the strains used, and especially higher level of IL-I beta could be detected in Actinobacillus. IL-6 was not produced in all the strains.