Positive- and Negative-Control Pathways by Blood Components for Intermedilysin Production in Streptococcus intermedius
Positive- and Negative-Control Pathways by Blood Components for Intermedilysin Production in Streptococcus intermedius
复制标题
中间链球菌中中间素生产的血液成分的阳性和阴性控制途径
DOI：
10.1128/iai.00379-17
复制
发表时间：
2017
影响因子：
3.1
通讯作者：
H.
中科院分区：
文献类型：
--
作者：
Tomoyasu;T.;Yamasaki;T.;Chiba;S.;Kusaka;S.;Tabata;A.;Whiley;R.A.;Nagamune;H.
中间链球菌是一种机会性细菌病原体，分泌一种人类特异性的细胞溶素，称为中间溶素（ILY），是主要的致病因子。这种细菌可以利用多底物糖苷酶A （MsgA）和神经氨酸酶（NanA）两种糖苷酶将多糖降解为单糖。在这里，我们检测到中间链球菌PC574在胎牛血清（FBS）中培养比在标准培养基中培养时具有更强的ILY介导的溶血活性。FBS培养的细胞也显示出更高的MsgA和NanA活性，尽管在突变体sana -null和MsgA -null中未检测到FBS中ILY的过量产生。将纯化的MsgA和NanA添加到FBS中，可释放2.8 mM半乳糖和4.3 mM n -乙酰神经氨酸；这些糖浓度足以上调ILY、MsgA和NanA的表达。相反，当菌株PC574在人血浆中培养时，没有观察到类似的溶血活性增加。此外，在FBS培养中加入人血浆似乎可以抑制FBS对ILY、MsgA和NanA的刺激作用，尽管血浆样本之间存在个体差异。我们证实，人血浆中含有免疫球蛋白，可以中和ILY， MsgA和NanA的活性。此外，人血浆对中间葡萄球菌对FBS中HepG2细胞的细胞毒性具有中和作用，并且需要更高浓度的人血浆来降低ily高产菌株的细胞毒性。总的来说，我们的数据表明血液中含有刺激和抑制ILY表达和活性的因子，这些因子可能影响中间葡萄球菌的致病性。
Streptococcus intermedius is an opportunistic bacterial pathogen secreting a human-specific cytolysin called intermedilysin (ILY) as a major pathogenic factor. This bacterium can degrade glycans into monosaccharides using two glycosidases, multisubstrate glycosidase A (MsgA) and neuraminidase (NanA). Here, we detected a stronger hemolytic activity mediated by ILY when S. intermedius PC574 was cultured in fetal bovine serum (FBS) than when it was grown in the standard culture medium. FBS-cultured cells also showed higher MsgA and NanA activity, although overproduction of ILY in FBS was undetectable in mutantsnanA-null andmsgA-null. Addition of purified MsgA and NanA to the FBS resulted in a release of 2.8 mM galactose and 4.3 mMN-acetylneuraminic acid; these sugar concentrations were sufficient to upregulate the expression of ILY, MsgA, and NanA. Conversely, when strain PC574 was cultured in human plasma, no similar increase in hemolytic activity was observed. Moreover, addition of human plasma to the culture in FBS appeared to inhibit the stimulatory effect of FBS on ILY, MsgA, and NanA, although there were individual differences among the plasma samples. We confirmed that human plasma contains immunoglobulins that can neutralize ILY, MsgA, and NanA activities. In addition, human plasma had a neutralizing effect on cytotoxicity of S. intermedius toward HepG2 cells in FBS, and a higher concentration of human plasma was necessary to reduce the cytotoxicity of an ILY-high-producing strain than an ILY-low-producing strain. Overall, our data show that blood contains factors that stimulate and inhibit ILY expression and activity, which may affect pathogenicity of S. intermedius.
登录
查看更多内容
小热休克蛋白AgsA：酶活性的有效稳定剂。
影响因子：
2.8
作者：
T. Tomoyasu;Atsushi Tabata;Y. Ishikawa;R. Whiley;H. Nagamune
通讯作者：
H. Nagamune
影响因子：
5.2
作者：
Jacobs, JA;Stobberingh, EE
通讯作者：
Stobberingh, EE
影响因子：
11.8
作者：
Bert, F;Bariou-Lancelin, M;Lambert-Zechovsky, N
通讯作者：
Lambert-Zechovsky, N
影响因子：
1.2
作者：
Noguchi, Shingo;Yatera, Kazuhiro;Mukae, Hiroshi
通讯作者：
Mukae, Hiroshi
乳酸乳球菌乳糖操纵子启动子的表征：侧翼序列和 LacR 阻遏物对启动子活性的贡献
影响因子：
3.2
作者：
Rutger J. vAN;Rooijen;Mike J. Gasson;W. M. D. Vos
通讯作者：
W. M. D. Vos