Asgarian-Omran Hossein, Amirzargar Ali Akbar, Zeerleder Sacha, Mahdavi Marzieh, van Mierlo Gerard, Solati Shabnam, Jeddi-Tehrani Mahmood, Rabbani Hodjatallah, Aarden Leucien, Shokri Fazel
Department of Immunology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran; Department of Immunology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
APMIS. 2015 Feb;123(2):156-62. doi: 10.1111/apm.12332. Epub 2014 Oct 29.
Filamentous hemagglutinin (FHA) is a major adhesion and virulence factor of Bordetella pertussis and also a main component of acellular pertussis vaccines. Interaction of FHA with different receptors on human epithelial and immune cells facilitates entrance and colonization of bacteria as well as immunomodulation of the host immune response. Three overlapping segments of the FHA gene were cloned in a prokaryotic expression vector and the recombinant proteins were purified. These recombinant fragments along with the native FHA protein were employed to assess their potential Toll-like receptor (TLR) stimulatory effects and to localize the TLR binding region. TLR stimulation was monitored by applying HEK293-Blue cell lines cotransfected with TLR2, 4, or 5 and a NF-κB reporter gene. Culture supernatants were checked for secretion of the reporter gene product and IL-8 as indicators of TLR stimulation. Native FHA was found to strongly stimulate TLR2, but not TLR4 or TLR5 transfected cells. Among recombinant FHA fragments only the fragment spanning amino acid residues 1544-1917 was able to exhibit the TLR2 stimulating property of FHA. Interaction of FHA with TLR2 suggests its involvement in induction of the innate immune system against Bordetella pertussis. The TLR2-binding domain of FHA may contribute to immunoprotection against pertussis infection.
丝状血凝素（FHA）是百日咳博德特氏菌的主要黏附及毒力因子，也是无细胞百日咳疫苗的主要成分。FHA与人类上皮细胞和免疫细胞上不同受体的相互作用有助于细菌的侵入和定植以及宿主免疫反应的免疫调节。将FHA基因的三个重叠片段克隆到原核表达载体中，并纯化重组蛋白。这些重组片段与天然FHA蛋白一起用于评估它们潜在的Toll样受体（TLR）刺激作用，并定位TLR结合区域。通过应用共转染了TLR2、4或5以及NF-κB报告基因的HEK293-Blue细胞系监测TLR刺激。检查培养上清液中报告基因产物和IL-8的分泌情况，作为TLR刺激的指标。发现天然FHA能强烈刺激转染了TLR2的细胞，但不能刺激转染了TLR4或TLR5的细胞。在重组FHA片段中，只有跨越氨基酸残基1544 - 1917的片段能够表现出FHA的TLR2刺激特性。FHA与TLR2的相互作用表明其参与了针对百日咳博德特氏菌的先天性免疫系统的诱导。FHA的TLR2结合结构域可能有助于对百日咳感染的免疫保护。
