Selective elimination of lymphocyte subpopulations by monoclonal antibody-enzyme conjugates.
A novel method for the selective depletion of lymphocyte subpopulations has been developed. Conjugates of glucose oxidase (GOx) and phospholipase-C (PL-C) coupled to a monoclonal mouse anti-rat IgG (MAR) were shown to be selectively cytotoxic for targeted lymphocyte subsets in the presence of various rat monoclonal antibodies directed toward murine cell surface antigens. The ability of both conjugates to bind specifically to rat monoclonal antibodies was demonstrated by flow cytometry. The PL-C-MAR conjugate was more stable than the GOx-MAR conjugate. The PL-C conjugate, in conjunction with primary rat anti-mouse monoclonal antibodies, produced selective killing of T or B cells as detected by a loss of proliferative capacity in response to mitogens and by specific cell depletion demonstrated by flow cytometry. Normal mouse serum protected against the cytotoxicity of free enzymes but had no protective effect on enzyme conjugates. Because the substrates of these enzymes are abundant in vivo and serum did not interfere with their cytotoxicity, these enzyme-antibody conjugates may be valuable for selective lymphocyte depletion in vivo.
D000818:Animals; D000911:Antibodies, Monoclonal; D000954:Antigens, Surface / Q000276:immunology*; D002374:Catalase / Q000378:metabolism; D002470:Cell Survival; D003602:Cytotoxicity, Immunologic; D004306:Dose-Response Relationship, Immunologic; D005949:Glucose Oxidase / Q000008:administration & dosage; D007124:Immunoenzyme Techniques; D008214:Lymphocytes / Q000145:classification* / Q000276:immunology; D051379:Mice; D008815:Mice, Inbred Strains; D013482:Superoxide Dismutase / Q000378:metabolism; D010738:Type C Phospholipases / Q000008:administration & dosage
D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D005949:Glucose Oxidase; D002374:Catalase; D013482:Superoxide Dismutase; D010738:Type C Phospholipases