Laboratory of Virology, Rocky Mountain Laboratories, NIAID, NIH, 903 S Fourth St, Hamilton, MT 59840, USA.
Ticks Tick Borne Dis. 2012 Feb;3(1):18-26. doi: 10.1016/j.ttbdis.2011.09.003. Epub 2012 Jan 2.
Ixodid ticks are vectors of human diseases such as Lyme disease, babesiosis, anaplasmosis, and tick-borne encephalitis. These diseases cause significant morbidity and mortality worldwide and are transmitted to humans during tick feeding. The tick-host-pathogen interface is a complex environment where host responses are modulated by the molecules in tick saliva to enable the acquisition of a blood meal. Disruption of host responses at the site of the tick bite may also provide an advantage for pathogens to survive and replicate. Thus, the molecules in tick saliva not only aid the tick in securing a nutrient-rich blood meal, but can also enhance the transmission and acquisition of pathogens. To investigate the effect of feeding and flavivirus infection on the salivary gland transcript expression profile in ticks, a first-generation microarray was developed using ESTs from a cDNA library derived from Ixodes scapularis salivary glands. When the salivary gland transcript profile in ticks feeding over the course of 3 days was compared to that in unfed ticks, a dramatic increase in transcripts related to metabolism was observed. Specifically, 578 transcripts were up-regulated compared to 151 down-regulated transcripts in response to feeding. When specific time points post attachment were analyzed, a temporal pattern of gene expression was observed. When Langat virus-infected ticks were compared to mock-infected ticks, transcript expression changes were observed at all 3 days of feeding. Differentially regulated transcripts include putative secreted proteins, lipocalins, Kunitz domain-containing proteins, anti-microbial peptides, and transcripts of unknown function. These studies identify salivary gland transcripts that are differentially regulated during feeding or in the context of flavivirus infection in Ixodes scapularis nymphs, a medically important disease vector. Further analysis of these transcripts may identify salivary factors that affect the transmission or replication of tick-borne flaviviruses.
硬蜱是人类疾病的传播媒介，如莱姆病、巴贝斯虫病、无形体病和蜱传脑炎。这些疾病在全球范围内造成了显著的发病率和死亡率，并且在蜱叮咬时传播给人类。蜱-宿主-病原体界面是一个复杂的环境，其中宿主反应受到蜱唾液中的分子调节，以促进血液餐的获取。在蜱叮咬部位破坏宿主反应也可能为病原体的存活和复制提供优势。因此，蜱唾液中的分子不仅有助于蜱获得营养丰富的血液餐，还可以增强病原体的传播和获取。为了研究进食和黄病毒感染对蜱类唾液腺转录表达谱的影响，使用从硬蜱唾液腺 cDNA 文库获得的 EST 开发了第一代微阵列。当比较 3 天内进食的蜱类的唾液腺转录谱与未进食的蜱类的转录谱时，观察到与代谢相关的转录物显著增加。具体而言，与进食相比，有 578 个转录物上调，151 个转录物下调。当分析特定的附着后时间点时，观察到基因表达的时间模式。当比较感染 Langat 病毒的蜱类与模拟感染的蜱类时，在所有 3 天的进食中观察到转录表达的变化。差异调节的转录物包括假定的分泌蛋白、脂联素、Kunitz 结构域蛋白、抗微生物肽和未知功能的转录物。这些研究鉴定了在硬蜱若虫进食期间或黄病毒感染背景下差异调节的唾液腺转录物，硬蜱若虫是一种重要的医学病媒。对这些转录物的进一步分析可能会确定影响蜱传黄病毒传播或复制的唾液因子。
