Successive tick infestations selectively promote a T-helper 2 cytokine profile in mice
Successive tick infestations selectively promote a T-helper 2 cytokine profile in mice
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DOI：
10.1046/j.1365-2567.1999.00683.x
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发表时间：
1999-03-01
期刊：
影响因子：
6.4
通讯作者：
Silva, JS
中科院分区：
文献类型：
--
作者：
Ferreira, BR;Silva, JS
多项研究表明，在保护性免疫方面，T淋巴细胞和细胞因子在决定寄生虫感染结局方面起着关键作用。在这项研究中，我们发现血圆头虫唾液刺激正常C3H/HeJ小鼠细胞分泌转化生长因子-β(TGF-β)，并减少白介素12(IL-12)的分泌。第四次感染后6天采集的小鼠淋巴结细胞对刀豆蛋白A(ConA)的增殖反应比对照细胞降低了82.4%。此外，在ConA存在下培养的淋巴结细胞呈现T辅助2型(Th2型)细胞因子谱，表现为增强的IL-4、IL-10和转化生长因子-β。另一方面，IL-2、干扰素-γ和IL-12的合成受到明显抑制。这些结果表明，扁虱可能通过唾液注射来调节宿主的免疫反应。考虑到C3H/HeJ小鼠对血吸虫感染没有产生保护性免疫，我们的结果表明壁虱诱导的Th2型细胞因子和增殖反应的降低可能导致宿主对壁虱和壁虱传播的病原体都处于易感状态。
Several studies have revealed that T lymphocytes and cytokines play a crucial role in determining the outcome of parasitic infections in terms of protective immunity. In this study we found that Rhipicephalus sanguineus tick saliva stimulates transforming growth factor-beta (TGF-beta), and reduces interleukin-12 (IL-12) secretion by cells from normal C3H/HeJ mice. Moreover, murine lymph node cells harvested 6 days after the fourth infestation with ticks presented an 82.4% decrease in their proliferative response to concanavalin A (Con A) compared with the response of control cells. In addition, lymph node cells cultured in the presence of Con A showed a T-helper 2-type (Th2-type) cytokine profile, represented by augmented IL-4 and IL-10 and TGF-beta. On the other hand, the IL-2, interferon-gamma (IFN-gamma) and IL-12 synthesis was significantly inhibited. These results indicate that ticks may modulate the host's immune response through saliva injection. Considering that C3H/HeJ mice develop no protective immunity to R sanguineus infestation, our results suggest that tick-induced Th2-type cytokines and a decreased proliferative response probably lead the host to a susceptible state to both tick and tick-transmitted pathogens.