cathepsin-g and Nephritis

After the injection of rabbit anti-mouse glomerular basement membrane (GBM) antibody into normal C57BL/6J mice severe albuminuria develops, which reaches a peak at 24 h. This early albuminuria is dependent on polymorphonuclear granulocytes (PMN) and is completely absent in the congenic beige mutant strain (C57BL/6J, bg/bg), which is genetically deficient in leukocytic neutral proteinase activity. We now studied the development of anti-GBM nephritis in beige mice during the later heterologous phase.. In untreated beige mice we assessed the albuminuria and glomerular lesions on days 1-5 after i.v. injection of anti-GBM antibody. Secondly, effector mechanisms involved in the later days of the heterologous phase were studied by substitution of whole anti-GBM antibodies by F(ab')2 fragments, by leukocyte depletion (total body irradiation), scavenging of reactive oxygen metabolites (dimethylsulfoxide treatment), and complement depletion (cobra venom factor treatment).. In the later part of the heterologous phase (days 2-5), when there is still no sign of autologous antibody formation, i.v. injection of anti-GBM antibodies in beige mice induces nephritis with gradually increasing albuminuria, that reaches levels similar to those in non-deficient, congenic controls by day 3. This late albuminuria did not occur after injection of F(ab')2 fragments of the antibody, could be prevented by leukocyte depletion, and was greatly reduced by treatment with dimethylsulfoxide, a scavenger of hydroxyl radicals. The late albuminuria was not influenced by complement depletion with cobra venom factor. Histologic and immunohistologic studies gave no indication for a role of glomerular macrophages or lymphocytes.. The heterologous phase in murine anti-GBM nephritis is a biphasic process, with sequential involvement of different and independent mediating systems: both phases are PMN-dependent, but only the early albuminuria depends on leukocytic neutral proteinase activity, whereas the albuminuria and the glomerular damage at later days are effected by reactive oxygen metabolites, most probably originating from PMN accumulating in the glomerulus.

Topics: Albuminuria; Animals; Antibodies; Autoantibodies; Basement Membrane; Cathepsin G; Cathepsins; Complement System Proteins; Dimethyl Sulfoxide; Female; Fluorescent Antibody Technique, Indirect; Immunoglobulin Fab Fragments; Kidney Glomerulus; Leukocyte Elastase; Lymphocyte Depletion; Male; Mice; Mice, Inbred C57BL; Nephritis; Neutrophils; Pancreatic Elastase; Rabbits; Serine Endopeptidases

Passive anti-glomerular basement membrane (GBM) nephritis in the mouse is accompanied by acute massive albuminuria in the early heterologous phase. As we have previously shown, this albuminuria does not occur in the beige mutant of the C57BL/6J strain which is deficient for the leukocytic neutral proteinases elastase and cathepsin G. To address the question whether an intrinsic defect in the polymorphonuclear granulocyte (PMN) or local factors in the beige kidney are responsible for the lack of albuminuria in the beige mouse strain, we conducted reciprocal bone marrow transplantations (BMT) in beige and congenic control mice. Injection of anti-GBM antibody resulted in only slight albuminuria (89 +/- 47 micrograms/18 hours; N = 6) in normal (that is, non-irradiated, non-reconstituted) beige mice. By contrast, in beige mice, reconstituted with bone marrow (BM) from control mice, acute albuminuria developed (3032 +/- 1408 micrograms/18 hours; N = 8), to a degree comparable to that in non-irradiated control mice (4411 +/- 3405 micrograms/18 hours; N = 6, P < 0.01). Albuminuria in control mice, reconstituted with beige BM, was in the range of the normal beige mice (112 +/- 55 micrograms/18 hours; N = 9). Reconstitution with syngeneic bone marrow demonstrated that BMT by itself did not influence the level of albuminuria. All mice showed similar morphological lesions, with comparable influx of PMN in the glomeruli two hours after antibody injection. Elastase activities of PMN extracts in BMT groups were not different from those in donor mice. We conclude that the absence of albuminuria in beige mice is caused by an intrinsic defect in leukocytic neutral proteinase activity.

Topics: Albuminuria; Animals; Antibodies; Basement Membrane; Bone Marrow Transplantation; Cathepsin G; Cathepsins; Disease Models, Animal; Kidney Glomerulus; Male; Mice; Mice, Inbred C57BL; Mice, Mutant Strains; Nephritis; Neutrophils; Pancreatic Elastase; Serine Endopeptidases