Generation of H₂O₂ by Human Neutrophils and Changes of Cytosolic Ca²⁺ and pH of Rat Thymocytes in Response to Galactoside-Binding Proteins (Lectins or Immunoglobulins) Available to Purchase

In contrast to plant agglutinins, biological activities of animal/human lectins are not well defined yet. Testing a panel of seven mammalian carbohydrate-binding proteins we have found that the dimeric lectin from chicken liver (CL-16) was a stimulator of H₂O₂ release from human neutrophils as well as effector for induction of cytosolic Ca²⁺ and pH increase in rat thymocytes. Activity of this lectin was comparable to potent galactoside-specific plant lectins such as Viscum album L. agglutinin. The activities of the tested plant lectins depended significantly on their nominal carbohydrate specificity as well as on the source. The results indicate that endogenous lectins may be involved in the regulation of neutrophil and lymphocyte functions by elicitation of selective biosignaling reactions.