Mechanism of Vector Saliva Inhibition of Innate Immunity

描述（由申请方提供）：硬蜱属蜱的唾液含有多种免疫调节成分，有助于蜱进食，是病原体的有效递送载体，包括生物防御C类病原体蜱传脑炎病毒和莱姆病病原体伯氏疏螺旋体（Bb）。在这个建议中，我们将测试我们的假设，从蜱唾液去整合素抑制多形核白细胞（PMN）的功能，从而提供了一个生存优势，以媒介传播的病原体。我们的计划源于我们以前的工作，其中我们已经表明，唾液抑制PMN粘附，并通过减少整合素表达降低病原体杀伤效率。我们将利用RNA干扰的新技术来抑制蜱唾液腺中去整合素的表达，以及重组去整合素，以评估抑制PMN功能的分子机制。我们将量化去整合素在体外对中性粒细胞活化标志物、炎症介质产生和信号通路的影响。此外，我们将使用莱姆病小鼠模型来研究去整合素对皮肤中性粒细胞功能的作用。这项工作的更大意义是鉴定唾液抑制PMN的机制，该机制可以通过治疗干预来利用，以提高宿主对媒介传播病原体的免疫力，包括生物防御关注的病原体。

DESCRIPTION (provided by applicant): Saliva of the Ixodes ticks contains numerous immunomodulatory components to aid tick feeding and is a potent delivery vehicle for pathogens, including Biodefense Category C agent tick-borne encephalitis virus and the Lyme disease agent, Borrelia burgdorferi (Bb). In this proposal, we will test our hypothesis that disintegrins from tick saliva inhibit polymorphonuclear leukocyte (PMN) function and thereby provide a survival advantage to vector-borne pathogens. Our plan stems from our previous work, in which we have shown that saliva inhibits PMN adherence and reduces efficiency of pathogen killing through reduction in integrin expression. We will use the novel technology of RNA interference to inhibit the expression of disintegrins in tick salivary glands, as well as recombinant disintegrins, to assess the molecular mechanisms of inhibition of PMN function. We will quantify the effect of disintegrins on markers of PMN activation, production of inflammatory mediators, and signaling pathways in vitro. In addition, we will address the role of disintegrins on PMN function in the skin using the murine model of Lyme disease. The greater significance of this work is the identification of a mechanism of saliva's inhibition of PMN that can be exploited by therapeutic interventions to improve host immunity against vector-borne pathogens, including those of Biodefense concern.