Th1 responsiveness to nephritogenic antigens determines susceptibility to crescentic glomerulonephritis in mice. The pattern of glomerulonephritis (GN) developing in response to a planted antigen (sheep anti-mouse GBM globulin) was compared in two strains of mice which demonstrated either a predominant Th1 (C57BL/6) or Th2 (BALB/c) response to this antigen. GN was induced with a subnephritogenic i.v. dose of sheep anti-mouse GBM globulin in mice presensitized to sheep globulin. Sensitized C57BL/6 mice showed pronounced cutaneous delayed-type hypersensitivity (DTH) following the challenge with sheep globulin, low titers of circulating anti-sheep globulin antibody and high interferon γ (IFNγ) and low interleukin 4 (IL-4) production by splenic T cells, consistent with a predominant Th1 pattern of immune response. Sensitized BALB/c mice did not develop DTH following cutaneous challenge with sheep globulin, had higher circulating anti-sheep globulin antibody titers, and showed high IL-4 and low IFNγ production by splenic T cells compared with C57BL/6 mice, consistent with a predominant Th2 response. In C57BL/6 mice, GN developing in response to sheep globulin exhibited a severe crescentic pattern with prominent glomerular T cell and macrophage influx and fibrin deposition. In vivo depletion with a monoclonal anti-CD4 antibody demonstrated that this injury was T helper cell dependent. Treatment with monoclonal anti-mouse IFNγ antibody significantly reduced glomerular injury and crescent formation and attenuated the cutaneous DTH response. GN induced by the same protocol in BALB/c mice exhibited pronounced glomerular IgG and complement deposition. Crescent formation, fibrin deposition, and glomerular T cell and macrophage infiltration were significantly less than observed in C57BL/6 mice, and injury was not T cell dependent in the effector phase. These data suggest that the pattern of glomerular injury induced by a planted antigen can be determined by the balance of T helper cell subset activation. A Th1 response induces a severe crescentic pattern of GN, which like cutaneous DTH, is T helper cell and IFNγ dependent.