Correlation between the activity of digestive enzymes and nonself recognition in the gut of Eisenia andrei earthworms

[Display omitted] •Laminarinase and glucosaminidase activities increase upon microbial stimulation.•CCF and lysozyme expression is up-regulated upon microbial stimulation.•Suggested cross-talk between digestive enzymes and innate defense in earthworms. Earthworms Eisenia andrei, similarly to other invertebrates, rely on innate defense mechanisms based on the capability to recognize and respond to nonself. Here, we show a correlation between the expression of CCF, a crucial pattern-recognition receptor, and lysozyme, with enzyme activities in the gut of E. andrei earthworms following a microbial challenge. These data suggest that enzyme activities important for the release and recognition of molecular patterns by pattern-recognition molecules, as well as enzymes involved in effector pathways, are modulated during the microbial challenge. In particular, protease, laminarinase, and glucosaminidase activities were increased in parallel to up-regulated CCF and lysozyme expression.