Expression of virulence factors under different environmental conditions in Aggregatibacter actinomycetemcomitans
Expression of virulence factors under different environmental conditions in Aggregatibacter actinomycetemcomitans
复制标题
DOI：
10.1111/1348-0421.12864
复制
发表时间：
2021-02-16
影响因子：
2.6
通讯作者：
Komatsuzawa，Hitoshi
中科院分区：
文献类型：
--
作者：
Fujita，Ayumi;Oogai，Yuichi;Komatsuzawa，Hitoshi
放线菌聚集菌是一种兼性厌氧革兰氏阴性细菌，与牙周疾病，尤其是侵袭性牙周炎相关。该病原体的毒力因子，包括粘附素、外毒素和内毒素，已被广泛研究。然而，人们对它们在宿主中的基因表达模式知之甚少。在此，我们研究了反映体内环境的培养条件（包括血清和唾液）是否会改变菌株 HK1651（JP2 克隆）中毒力基因的表达水平。在有氧条件下，将小牛血清（CS）添加到普通培养基中诱导两种外膜蛋白（omp100andomp64）的高表达。 omp100和domp64的高表达也是由铁限制培养基诱导的。 RNA-seq 分析表明，在含 CS 的培养基中，与铁获取相关的几个因子的基因表达增加。当 HK1651 在琼脂平板上生长时，编码许多毒力因子（包括 Omp、细胞致死膨胀毒素和白细胞毒素）的基因出现差异表达。然后，我们研究了它们在其他五个A中的表达。在普通培养基和含 CS 的培养基中生长的放线菌菌株。毒力因子的表达模式因菌株而异。与其他5个菌株相比，无论是否添加CS，HK1561均显示出omp29的高表达，而HK1651中的白细胞毒素基因表达仅在不添加CS的培养基中较高。 HK1651 在含 CS 和唾液的培养基中均显示出生物膜减少。使用在含 CS 的培养基中生长的 HK1651，与具核梭杆菌的共聚集显着增强。我们的结果表明，毒力因子的表达通过适应感染期间的不同条件而改变。
Aggregatibacter actinomycetemcomitansis a facultative anaerobic Gram‐negative bacterium associated with periodontal diseases, especially aggressive periodontitis. The virulence factors of this pathogen, including adhesins, exotoxins, and endotoxin, have been extensively studied. However, little is known about their gene expression mode in the host. Herein, we investigated whether culture conditions reflecting in vivo environments, including serum and saliva, alter expression levels of virulence genes in the strain HK1651, a JP2 clone. Under aerobic conditions, addition of calf serum (CS) into a general medium induced high expression of two outer membrane proteins (omp100andomp64). The high expression ofomp100andomp64was also induced by an iron‐limited medium. RNA‐seq analysis showed that the gene expressions of several factors involved in iron acquisition were increased in the CS‐containing medium. When HK1651 was grown on agar plates, genes encoding many virulence factors, including the Omps, cytolethal distending toxin, and leukotoxin, were differentially expressed. Then, we investigated their expression in five otherA. actinomycetemcomitansstrains grown in general and CS‐containing media. The expression pattern of virulence factors varied among strains. Compared with the other five strains, HK1561 showed high expression ofomp29regardless of the CS addition, while the gene expression of leukotoxin in HK1651 was higher only in the medium without CS. HK1651 showed reduced biofilm in both CS‐ and saliva‐containing media. Coaggregation withFusobacterium nucleatumwas remarkably enhanced using HK1651 grown in the CS‐containing medium. Our results indicate that the expression of virulence factors is altered by adaptation to different conditions during infection.