Human lymphocyte activation is associated with the early and high-level expression of the endogenous lectin CSL at the cell surface.
Lymphocytes undergo activation in response to antigens, cytokines, lectins and antibodies interacting with specific cell-surface molecules or through substances influencing signal transduction pathways. This study shows that human T- and B-cells stimulated using phorbol esters or plant lectins express early (2 h using phorbol esters and 24 h using plant lectins) a high level of a polyvalent carbohydrate-binding protein, the cerebellar soluble lectin (CSL), which is in part externalized. The lectin, immunologically related to CDw70, interacts with specific glycoprotein ligands of the lymphocyte surface, including CD3 on T-cells and CD24 on B-cells. Major changes in phosphorylations associated with activation appear as largely CSL-dependent since they are specifically inhibited by anti-CSL Fab fragments. It is suggested that the lectin induces the clustering of specific cell-surface glycoproteins and plays the role of an endogenous amplifier of activation signals.
D000372:Agglutination Tests; D015703:Antigens, CD / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology*; D051927:CD24 Antigen; D017252:CD3 Complex / Q000276:immunology; D002462:Cell Membrane / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D007124:Immunoenzyme Techniques; D037102:Lectins / Q000096:biosynthesis* / Q000276:immunology / Q000494:pharmacology; D008024:Ligands; D008213:Lymphocyte Activation / Q000187:drug effects; D008562:Membrane Glycoproteins / Q000276:immunology; D010766:Phosphorylation; D012751:Sezary Syndrome / Q000276:immunology; D012878:Skin Neoplasms / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D015703:Antigens, CD; D051927:CD24 Antigen; C497889:CD24 protein, human; D017252:CD3 Complex; D037102:Lectins; D008024:Ligands; D008562:Membrane Glycoproteins; C059525:cerebellar soluble lectin; D013755:Tetradecanoylphorbol Acetate