Liu J, Renneker S, Beyer D, Kullmann B, Seitzer U, Ahmed J, Bakheit M A
Division of Veterinary Infection Biology and Immunology, Department of Molecular Infection Biology, Research Center Borstel, Germany.
Division of Veterinary Infection Biology and Immunology, Department of Molecular Infection Biology, Research Center Borstel, Germany.
Ticks Tick Borne Dis. 2014 Apr;5(3):318-22. doi: 10.1016/j.ttbdis.2013.12.004. Epub 2014 Feb 23.
The immunomodulatory molecule Salp15 is originally described in Ixodes scapularis and has been shown to inhibit CD4 T cell activation. Many Salp15 homologs have been described from Ixodes species, and all were well conserved at C-terminal residues that seem to be essential for the function of the protein. In this study, a gene sequence was amplified from cDNA isolated from engorged female I. ricinus ticks, which was predicted to generate a protein of 12.3 kDa. The protein displayed distinct amino acid differences from previously described I. ricinus Salp15 homologs, with amino acid identity ranging between 46.6% and 93.9%. It was referred to as I. ricinus Salp15-like protein. The protein showed 48.1% sequence identity to I. scapularis Salp15. We analyzed the effect of the recombinant I. ricinus Salp15-like protein on the production of cytokines from human peripheral blood mononuclear cells stimulated with LPS. The recombinant protein exerted no effect on the production of TNF-α and IL-6, but the production of IL-10 was dose-dependently reduced. It can be concluded that I. ricinus Salp15-like protein exerts an immunomodulatory effect on the host. The inhibition of IL-10 production may possibly lead to a retardation of B cell activity.
免疫调节分子Salp15最初是在肩突硬蜱中发现的,已被证明可抑制CD4 T细胞的激活。已从硬蜱属物种中描述了许多Salp15同源物,并且所有同源物在C末端残基处都高度保守,这些残基似乎对该蛋白质的功能至关重要。在本研究中,从饱血的蓖麻硬蜱雌蜱分离的cDNA中扩增出一个基因序列,预测该序列可产生一种12.3 kDa的蛋白质。该蛋白质与先前描述的蓖麻硬蜱Salp15同源物表现出明显的氨基酸差异,氨基酸同一性在46.6%至93.9%之间。它被称为蓖麻硬蜱Salp15样蛋白。该蛋白质与肩突硬蜱Salp15的序列同一性为48.1%。我们分析了重组蓖麻硬蜱Salp15样蛋白对用LPS刺激的人外周血单个核细胞产生细胞因子的影响。重组蛋白对TNF-α和IL-6的产生没有影响,但IL-10的产生呈剂量依赖性降低。可以得出结论,蓖麻硬蜱Salp15样蛋白对宿主具有免疫调节作用。IL-10产生的抑制可能会导致B细胞活性的延迟。