Department of Molecular Microbiology & Immunology, Oregon Health & Science University, Portland, United States.
Elife. 2019 Nov 1;8:e50033. doi: 10.7554/eLife.50033.
The recognition of pathogens and subsequent activation of defense responses are critical for the survival of organisms. The nematode recognizes pathogenic bacteria and elicits defense responses by activating immune pathways and pathogen avoidance. Here we show that chemosensation of phenazines produced by pathogenic , which leads to rapid activation of DAF-7/TGF-β in ASJ neurons, is insufficient for the elicitation of pathogen avoidance behavior. Instead, intestinal infection and bloating of the lumen, which depend on the virulence of , regulates both pathogen avoidance and aversive learning by modulating not only the DAF-7/TGF-β pathway but also the G-protein coupled receptor NPR-1 pathway, which also controls aerotaxis behavior. Modulation of these neuroendocrine pathways by intestinal infection serves as a systemic feedback that enables animals to avoid virulent bacteria. These results reveal how feedback from the intestine during infection can modulate the behavior, learning, and microbial perception of the host.
生物体的生存依赖于对病原体的识别以及随之激活的防御反应。线虫通过激活免疫途径和避免接触病原体来识别致病细菌并引发防御反应。在这里，我们发现致病性细菌产生的苯醌的化学感应作用，导致 ASJ 神经元中 DAF-7/TGF-β 的快速激活，这不足以引发病原体回避行为。相反，肠道感染和腔室肿胀，这依赖于 的毒力，通过调节不仅 DAF-7/TGF-β 途径，而且还调节 G 蛋白偶联受体 NPR-1 途径，这也控制气趋性行为，调节病原体回避和厌恶学习。肠道感染对这些神经内分泌途径的调节作为一种系统反馈，使动物能够避免有毒细菌。这些结果揭示了感染过程中肠道的反馈如何调节宿主的行为、学习和微生物感知。
