title: Surface proteolytic activity in cell interactions: activation of human peripheral lymphocytes in contact with mitogen-treated glass-adherent leukocytes.
abstract: The transformation of lymphocytes by mitogens or by periodate treatment requires the presence of glass-adherent leukocytes. We have demonstrated that contact with periodate-treated adherent cells transforms human peripheral T lymphocytes. Using a new method to estimate proteolytic activity released by cells or available at cell surfaces, we found marked stimulation of cell surface-associated enzyme activity on glass-adherent cells treated by NaIO4 or by Con A. The expression of this enzymatic stimulation required contact with substrate, just as the transformation of untreated T cells required contact with treated adherent cells. Therefore, we propose that cell-cell interaction leads to an efficient mode of stimulation, which may be mediated by or initiated by surface-associated proteases of adherent cells.
mesh_terms: D002448:Cell Adhesion; D002450:Cell Communication; D002462:Cell Membrane / Q000502:physiology; D003208:Concanavalin A / Q000494:pharmacology; D006801:Humans; D066298:In Vitro Techniques; D007962:Leukocytes / Q000502:physiology*; D008213:Lymphocyte Activation; D008934:Mitogens / Q000494:pharmacology*; D010447:Peptide Hydrolases / Q000502:physiology*; D010504:Periodic Acid / Q000494:pharmacology; D013601:T-Lymphocytes / Q000502:physiology
chemical_list: D008934:Mitogens; D010504:Periodic Acid; D003208:Concanavalin A; D010447:Peptide Hydrolases