title: Treatment of autoimmune MRL/Ipr mice with monoclonal antibody to Thy-1.2: a single injection has sustained effects on lymphoproliferation and renal disease.
abstract: MRL/Mp-lpr/lpr (MRL/lpr) mice spontaneously develop an autoimmune disease characterized by anti-DNA antibodies, immune-complex glomerulonephritis, and massive proliferation of a distinct population of T cells. The proliferating T cells have the phenotype Thy-1.2+, T200+, Lyt-1+,2-,3-, but Thy-1.2 and Lyt-1 are expressed in abnormally low density. These cells appear to function as helper cells, and neonatal thymectomy prevents both lymphoproliferation and autoimmunity, which suggests that autoimmunity in MRL/lpr mice is secondary to T cell proliferation. We therefore attempted to reduce lymphoproliferation by treating MRL/lpr mice with a single injection of rat monoclonal antibody (MAb) to Thy-1.2 (30-H12, IgG2b). Mice were treated at 8 wk, before the onset of overt disease. We found that MRL/lpr mice were resistant to depletion of circulating T cells (CTC) by anti-Thy-1.2; 0.6 mg of antibody totally depleted CTC from normal mice, but had little or no effect on CTC in MRL/lpr mice. However, treatment with 6 mg of MAb against Thy-1.2 reduced CTC in MRL/lpr mice by over 70%. Moreover, this single treatment markedly reduced the proliferation of CTC over the ensuing 3 mo, despite clearance of the anti-Thy-1.2 from the circulation within 3 wk. Treated mice maintained better renal function than untreated controls, as assessed by levels of blood urea nitrogen (BUN), although anti-DNA antibodies were not significantly reduced. The effect of anti-Thy-1.2 was specific; treatment with rat MAb to the common leukocyte antigen T200 produced only a transient effect on circulating lymphocytes and did not reduce renal disease. The prolonged effects of a single injection of anti-Thy-1.2 suggest that the MAb produces a sustained alteration in immune regulation. The improvement in renal disease is in accord with evidence that autoimmune disease in MRL/lpr mice is T cell dependent. Monoclonal anti-lymphocyte antibodies may be useful in the treatment of autoimmunity.
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000008:administration & dosage* / Q000032:analysis; D000954:Antigens, Surface / Q000276:immunology*; D001327:Autoimmune Diseases / Q000276:immunology* / Q000628:therapy; D000939:Epitopes; D005260:Female; D005921:Glomerulonephritis / Q000276:immunology / Q000503:physiopathology / Q000628:therapy; D007958:Leukocyte Count; D008213:Lymphocyte Activation; D051379:Mice; D008815:Mice, Inbred Strains; D008819:Mice, Nude; D011507:Proteinuria / Q000175:diagnosis / Q000628:therapy; D051381:Rats; D013601:T-Lymphocytes / Q000276:immunology; D018800:Thy-1 Antigens
chemical_list: D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D000939:Epitopes; D018800:Thy-1 Antigens