Oral streptococci show diversity in resistance to complement immunity
Oral streptococci show diversity in resistance to complement immunity
复制标题
DOI：
10.1099/jmm.0.000955
复制
发表时间：
2019-04-01
影响因子：
3
通讯作者：
Mattos-Graner, Renata O.
中科院分区：
文献类型：
--
作者：
Alves, Livia A.;de Carli, Thais R.;Mattos-Graner, Renata O.
目的.目前人们对缓和链球菌（缓和链球菌、口腔链球菌）和血链球菌（戈登链球菌、血链球菌）共生链球菌口腔种全身感染的机制知之甚少。本研究调查了这四个物种的代表性菌株对补体介导的宿主免疫的敏感性，这些菌株分离自口腔部位或血液。通过流式细胞术对34株经人血清（HS）处理的菌株的补体调理素（C3 b/iC 3b）沉积以及与C反应蛋白（CRP）和IgG抗体的表面结合进行定量，并与补体（CR 1/3）和/或IgG Fc（Fc γ RII/III）受体介导的人PMN调理吞噬作用的速率进行比较。S.与其他物种相比，血吸虫菌株显示对补体调理作用的敏感性降低，并且与CRP和IgG的结合低。C_3b/iC_3b在S. sanguinis株的平均毒力分别是S. gordonii和Mitis菌株。C3 b/iC 3b沉积的多样性在Mitis物种中是明显的，其中C3 b/iC 3b沉积与PMN的CR/Fc γ R依赖性调理吞噬作用显著相关（P
Purpose. Mechanisms underlying systemic infections by oral species of Mitis (Streptococcus mitis, Streptococcus oralis) and Sanguinis (Streptococcus gordonii, Streptococcus sanguinis) commensal streptococci are poorly understood. This study investigates profiles of susceptibility to complement-mediated host immunity in representative strains of these four species, which were isolated from oral sites or from the bloodstream.Methodology. Deposition of complement opsonins (C3b/iC3b), and surface binding to C-reactive protein (CRP) and to IgG antibodies were quantified by flow cytometry in 34 strains treated with human serum (HS), and compared to rates of opsonophagocytosis by human PMN mediated by complement (CR1/3) and/or IgG Fc (Fc gamma RII/III) receptors.Results. S. sanguinis strains showed reduced susceptibility to complement opsonization and low binding to CRP and to IgG compared to other species. Surface levels of C3b/iC3b in S. sanguinis strains were 4.5-and 7.8-fold lower than that observed in S. gordonii and Mitis strains, respectively. Diversity in C3b/iC3b deposition was evident among Mitis species, in which C3b/iC3b deposition was significantly associated with CR/Fc gamma R-dependent opsonophagocytosis by PMN (P