Immunomodulatory stimulation of an invertebrate circulatory lectin by its haptenic molecules of pathogenic origin

2-keto-3-deoxy octonate and beta-glycerophosphate two important bacterial cell wall constituent molecules, haptenic in nature to an invertebrate (crab) circulatory lectin, carcinoscorpin, gave lectin induction after immunization of the crab, Carcinoscorpius rotunda-cauda. With the exception of erythrocyte, no other sialoglycoconjugate-containing substances (mucin, fetuin) sialodisaccharide O-[N-acetylneuraminyl-(2----6)2-acetamido-2-deoxy galactitol] and free sialic acid were effective in lectin induction. This induction of circulatory lectin failed to appear when, concanavalin A, epinephrine, cytochalasin B, methyl-alpha-D-mannoside and bovine serum albumin were used for immunization. But mechanical injury to crabs were extremely effective in such lectin induction by live crabs. LPS is lethal if used for immunization. The immunoregulatory induction of the circulatory lectin by pathogen-originated cell wall constituent molecules and mechanical injury may be considered as a humoral immune response.