Luu Laurence Don Wai, Octavia Sophie, Zhong Ling, Raftery Mark J, Sintchenko Vitali, Lan Ruiting
School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia.
Bioanalytical Mass Spectrometry Facility, University of New South Wales, Sydney, NSW, Australia.
Front Microbiol. 2018 Nov 27;9:2851. doi: 10.3389/fmicb.2018.02851. eCollection 2018.
Sulfate is an important modulator for virulence factor expression in , the causative organism for whooping cough. During infection, sulfate is released when respiratory epithelial cells are damaged which can affect gene expression. The current predominant strains in Australia are found in single nucleotide polymorphism (SNP) cluster I (). It has been reported that strains have higher mRNA expression of virulence genes than strains under intermediate sulfate-modulating conditions (5 mM MgSO). Our previous proteomic study compared L1423 (cluster I, ) and L1191 (cluster II, ) in Thalen-IJssel (THIJS) media without sulfate modulation and identified an upregulation of transport proteins and a downregulation of immunogenic proteins. To determine whether proteomic differences exist between cluster I and cluster II strains in intermediate modulating conditions, this study compared the whole cell proteome and secretome between L1423 and L1191 grown in THIJS media with 5 mM MgSO using iTRAQ and high-resolution multiple reaction monitoring (MRM-hr). Two proteins (BP0200 and BP1175) in the whole cell were upregulated in L1423 [fold change (FC) >1.2, false discovery rate (FDR) <0.05]. In the secretome, four proteins from the type III secretion system (T3SS) effectors were downregulated (FC < 0.8, FDR < 0.05) while six proteins, including two adhesins, pertactin (Prn) and tracheal colonization factor A (TcfA), were upregulated which were consistent with our previous proteomic study. The upregulation of Prn and TcfA in SNP cluster I may result in improved adhesion while the downregulation of the T3SS and other immunogenic proteins may reduce immune recognition, which may contribute to the increased fitness of cluster I strains.
硫酸盐是百日咳致病原 中毒力因子表达的重要调节因子。在感染过程中，呼吸道上皮细胞受损时会释放硫酸盐，这可能会影响基因表达。澳大利亚目前的主要菌株存在于单核苷酸多态性（SNP）簇I（ ）中。据报道，在中等硫酸盐调节条件（5 mM MgSO）下， 菌株的毒力基因mRNA表达高于 菌株。我们之前的蛋白质组学研究比较了在无硫酸盐调节的塔伦 - 艾瑟尔（THIJS）培养基中的L1423（簇I， ）和L1191（簇II， ），并确定了转运蛋白的上调和免疫原性蛋白的下调。为了确定在中等调节条件下簇I和簇II菌株之间是否存在蛋白质组差异，本研究使用iTRAQ和高分辨率多反应监测（MRM - hr）比较了在含有5 mM MgSO的THIJS培养基中生长的L1423和L1191的全细胞蛋白质组和分泌蛋白质组。全细胞中的两种蛋白质（BP0200和BP1175）在L1423中上调[倍数变化（FC）>1.2，错误发现率（FDR）<0.05]。在分泌蛋白质组中，来自III型分泌系统（T3SS）效应器的四种蛋白质下调（FC < 0.8，FDR < 0.05），而六种蛋白质，包括两种黏附素、百日咳杆菌黏附素（Prn）和气管定植因子A（TcfA）上调，这与我们之前的蛋白质组学研究一致。SNP簇I中Prn和TcfA的上调可能导致黏附改善，而T3SS和其他免疫原性蛋白质的下调可能会降低免疫识别，这可能有助于簇I 菌株适应性的增加。
