目的 比较具有不同毒力特性的牙龈卟啉单胞菌(Porphyromonas gingivalis,Pg)临床菌株的多糖成分诱导人单核细胞系THP-1细胞分泌白细胞介素(interleukin,IL)Ip、IL-8和肿瘤坏死因子α(tumor necrosis factor-α,TNF-α)的能力,分析Pg多糖成分的免疫原性,探讨Pg的毒力相关因素.方法 酚-水提取法提取Pg高毒力标准菌株W83、高毒力临床菌株SJD2和SJD12(高毒株组)、低毒力标准菌株ATCC33277及低毒力临床菌株SJD4、SJD5和SJD11(低毒株组)的多糖成分,并作用于人单核细胞系THP-1细胞,利用酶联免疫吸附测定(enzyme-linked immunosorbent assay,ELISA)法检测在10%和1%胎牛血清环境中,不同刺激物浓度、不同刺激时间下细胞上清液中IL-1β、IL-8和TNF-α的浓度.结果 酚-水提取法获得各菌株多糖成分,经鉴定主要含有脂多糖及荚膜多糖成分.在含10%胎牛血清培养基中,各菌株多糖提取物诱导THP-1细胞分泌IL-1β、IL-8和TNF-α均呈时间、剂量依赖性;在含1%胎牛血清的培养基中,高毒株组IL-1β[4 h:(1 639 ±497) μg/L]、IL-8[4 h:(1 648 ±513) μg/L]及TNF-α的质量浓度[4 h:(140 ±48)μg/L]均显著高于低毒株组[4h时IL-1β、IL-8及TNF-α质量浓度分别为(773 ±382)、(892 ±400)及(67±33) μg/L].结论 Pg多糖提取物具有免疫原性,可以诱导THP-1细胞分泌IL-1β、IL-8和TNF-α;各菌株诱导THP-1细胞表达细胞因子的能力可能与其毒力密切相关.
Objective To compare the ability of the polysaccharide from various Porphyromonas gingivalis(Pg) type and clinical strains in inducing THP-1 cells to produce cytokines interleukin (IL)-113, IL-8, and tumor necrosis factor (TNF)-ct, in order to analyze the immunogenicity of Pg polysaccharide components and the virulence-associated factors of this periodontal pathogen. Methods The bacterial polysaccharide was extracted from high virulent Pg strains, W83, SJD2, SJD12 and low virulent Pg, ATCC33277,SJD4,SJD5, and SJD11 by phenol-water extraction. The extracted polysaccharide was used to stimulate the THP-1 cells with different simulation periods and doses. The level of the cytokines, including IL-113, IL-8 and TNF-a in the cell culture suspension was measured by enzyme-linked immunosorbent assay (ELISA). Results The polysaccharide extraction of Pg strains was composed of lipopolysaccharide (LPS) and capsular polysaccharide. The secretion of IL-1β, IL-8 and TNF-α, produced by the THP-1 cells showed in a time- and dose-dependent manner in the medium containing 10% fetal bovine serum. The level of these cytokines of the high virulent strains was higher than that of the low virulent strains in medium containing 1% fetal bovine serum. Four hours after stimulation with polysaccharide extracted from high virulent strains, the levels of IL-1 β, IL-8, and TNF-α in the cell suspension were (1 639 ± 497), (1 648 ± 513)and (140 ± 48 ) ug/L, respectively ,whereas for low virulent strains, the levels of IL-1 β, IL-8, and TNF-α were (773 ± 382), ( 892 ±400 ) and ( 67 ± 33 ) ug/L, respectively. Conclusions Polysaccharidc extracted from Pg could induced the THP-1 cells to secrete the cytokines of IL-1β,IL-8 and TNF-α. The level of the cytokines produced by the THP-1 cells associates with the bacterial virulent properties.