Insect immunity shows specificity in protection upon secondary pathogen exposure
Insect immunity shows specificity in protection upon secondary pathogen exposure
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DOI：
10.1016/j.cub.2006.04.047
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发表时间：
2006-06-20
期刊：
影响因子：
9.2
通讯作者：
Schmid-Hempel, Paul
中科院分区：
文献类型：
--
作者：
Sadd, Ben M.;Schmid-Hempel, Paul
脊椎动物的免疫记忆在初次接触病原体后提供持久的特异性保护，对广泛的进化、流行病学和医学现象具有影响[1]。然而，无脊椎动物对继发病原体暴露的保护是否存在特异性仍存在争议[1-6]。为了将这种功能现象与特定机制区分开来，我们将其称为特异性免疫启动。我们研究了社会性昆虫 Bombus terrestris 工蜂中是否存在特异性免疫启动。使用三种细菌病原体，我们测试了先前的同源病原体暴露是否比异源组合更能提供长期保护以抵御后来的挑战。通过相互设计的初次和第二次暴露方案（即测试所有细菌组合），我们证明，即使在第一次暴露清除几周后，二次暴露时的保护性也有所增强，特异性也较窄。这表明无脊椎动物免疫系统在功能上能够产生意想不到的特异性和持久的诱导保护。最终，尽管脊椎动物和无脊椎动物之间存在广泛的差异，但两种免疫系统表现出特异性保护的能力表明，它们的免疫防御在进化过程中已经找到了针对类似选择压力的类似解决方案。
Immunological memory in vertebrates, conferring lasting specific protection after an initial pathogen exposure, has implications for a broad spectrum of evolutionary, epidemiological, and medical phenomena [1]. However, the existence of specificity in protection upon secondary pathogen exposure in invertebrates remains controversial [1-6]. To separate this functional phenomenon from a particular mechanism, we refer to it as specific immune priming. We investigate the presence of specific immune priming in workers of the social insect Bombus terrestris. Using three bacterial pathogens, we test whether a prior homologous pathogen exposure gives a benefit in terms of long-term protection against a later challenge, over and above a heterologous combination. With a reciprocally designed initial and second-exposure protocol (i.e., all combinations of bacteria were tested), we demonstrate, even several weeks after the clearance of a first exposure, increased protection and narrow specificity upon secondary exposure. This demonstrates that the invertebrate immune system is functionally capable of unexpectedly specific and durable induced protection. Ultimately, despite general broad differences between vertebrates and invertebrates, the ability of both immune systems to show specificity in protection suggests that their immune defenses have found comparable solutions to similar selective pressures over evolutionary time.