State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling 712100, China.
Institute of Environmental Microbiology, College of Resource and Environment, Fujian Agriculture & Forestry University, Fuzhou 350002, China.
Int J Mol Sci. 2023 Jun 2;24(11):9694. doi: 10.3390/ijms24119694.
The symbiotic bacteria-insect interaction is considered to be associated with immunity and drug resistance. However, the wide variety of insect species and habitats is thought to have a significant impact on the symbiotic community, leading to disparate results. Here, we demonstrated that symbiotic bacteria regulated the immune response by changing the proportion of the Gram-positive and the Gram-negative bacterial community in () after infection with its viral pathogen, Nucleopolyhedrovirus (LdMNPV). After oral infection, the immune deficiency pathway was activated immediately, and the expression of was up-regulated to promote the secretion of antimicrobial peptides. Meanwhile, the abundance of the Gram-negative bacterial community increased at the same time. Moreover, the Toll pathway was not regulated in the same way as the Imd pathway was after infection. However, the change in the Toll pathway's expression remained positively correlated to the abundance of Gram-positive bacteria. This finding implied that the ratio of Gram-negative to Gram-positive bacteria in the LdMNPV infected larvae had an effect on the immune response. Our findings revealed that the immune regulation of was regulated by the relative abundance of its symbiotic bacteria at different infection times with LdMNPV, which provides a new way to understand symbiotic bacteria-insect interactions.
共生细菌-昆虫的相互作用被认为与免疫和抗药性有关。然而，昆虫种类和栖息地的多样性被认为对共生群落有重大影响，导致结果不一致。在这里，我们证明共生细菌通过改变感染其病毒病原体（LdMNPV）后 （）中革兰氏阳性菌和革兰氏阴性菌群落的比例来调节免疫反应。口服感染后，免疫缺陷途径立即被激活，并且 的表达上调以促进抗菌肽的分泌。同时，革兰氏阴性菌群落的丰度也同时增加。此外，感染后 Toll 途径的调节方式与 Imd 途径不同。然而，Toll 途径表达的变化仍然与革兰氏阳性菌的丰度呈正相关。这一发现表明，LdMNPV 感染幼虫中革兰氏阴性菌与革兰氏阳性菌的比例对免疫反应有影响。我们的研究结果表明，在不同的 LdMNPV 感染时间，共生细菌的相对丰度调节了 的免疫调节，这为理解共生细菌-昆虫的相互作用提供了一种新的方式。
