Sadd Ben M, Schmid-Hempel Paul
Institute for Integrative Biology, Experimental Ecology, Eidgnössische Technische Hochschule Zentrum, CHN, CH-8092 Zurich, Switzerland.
Curr Biol. 2006 Jun 20;16(12):1206-10. doi: 10.1016/j.cub.2006.04.047.
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 . However, the existence of specificity in protection upon secondary pathogen exposure in invertebrates remains controversial . 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.
脊椎动物的免疫记忆，在初次接触病原体后能提供持久的特异性保护，这对广泛的进化、流行病学和医学现象都有影响。然而，无脊椎动物在二次接触病原体时保护作用的特异性是否存在仍存在争议。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致敏。我们研究了社会性昆虫熊蜂工蜂中特异性免疫致敏的存在情况。我们使用三种细菌病原体，测试先前同源病原体暴露是否能在针对后续挑战的长期保护方面，比异源组合提供更多益处。通过相互设计的初次和二次暴露方案（即测试所有细菌组合），我们证明，即使在初次暴露清除数周后，二次暴露时仍有增强的保护作用和狭窄的特异性。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普遍的广泛差异，但两个免疫系统在保护中表现出特异性的能力表明，在进化过程中，它们的免疫防御针对类似的选择压力找到了可比的解决方案。
