Coelomic fluid proteins as basic components of innate immunity in earthworms

Coelomic fluid (CF) of earthworms contains cells and many molecular components involved in innate immunity. Glycoproteins of lectin character contribute to recognition of foreign material by binding to carbohydrates and cause its immobilisation and destruction by agglutination and lysis. Analysing several earthworm species (Allolobophora chlorotica, Apporectodea caliginosa, Dendrodrillus rubidus, Eisenia fetida, Lumbricus rubellus, L. terrestris) we showed earlier that wounding and injection of foreign material into the coelomic cavity increases coelomocyte numbers and the activity of easily measurable humoral immune factors like agglutinins, lysins and proteases [I. Eue, E. Kauschke, W. Mohrig, E.L. Cooper, Isolation and characterization of earthworm hemolysins and agglutinins, Dev. Comp. Immunol. 22 (1998) 13--26; E. Kauschke, W. Mohrig, The occurrence of bacterioagglutinating, hemagglutinating and hemolytic compounds in the coelomic fluid of different European earthworm species, Zool. Jb. Physiol. 91 (1987) 467--477; E. Kauschke, P. Pagliara, L. Stabili, E.L. Cooper, Characterization of proteolytic activity in coelomic fluid of Lumbricus terrestris, L. Comp. Biochem. Physiol. 118B (2) (1997) 235--242; W. Mohrig, I. Eue, E. Kauschke, Proteolytic activities in the coelomic fluid of earthworms (Annelida, Lumbricidae), Zool. Jb. Physiol. 93 (1989) 303--317; W. Mohrig, I. Eue, E. Kauschke, F. Hennicke, Crossreactivity of hemolytic and heamagglutinating proteins in the coelomic fluid of earthworms, Comp. Biochem. Physiol. 115A (1) (1996) 19--30]. Earthworm CF proteases are relatively heat stable, posses an activity optimum at neutral to basic pH and are classified mainly as serine proteases [E. Kauschke, P. Pagliara, L. Stabili, E.L. Cooper, Characterization of proteolytic activity in coelomic fluid of Lumbricus terrestris, L. Comp. Biochem. Physiol. 118B (2) (1997) 235--242; W. Mohrig, I. Eue, E. Kauschke, Proteolytic activities in the coelomic fluid of earthworms (Annelida, Lumbricidae), Zool. Jb. Physiol. 93 (1989) 303--317]. Herein we focus on protease activity of the species A. caliginosa and L. rubellus, by characterizing activity parameters (time course, pH optimum, temperature sensitivity) and by comparing enzyme patterns of untreated and stimulated CF samples separated by PAGE. Disturbance of homeostasis in earthworms results in an increased immune response. Some of the immune proteins might be considered as suitable biomarkers in monitoring environmental conditions. Especially protease pattern and protease activity may be considered as promising candidates in that regard and are easy to analyse.