We developed a convenient and reliable procedure for the cell-mediated passive transfer of type II collagen (CII)-induced arthritis (CA). Spleen cells from DBA/1 mice with CA were intravenously transferred into syngeneic recipient mice. Arthritis developed only in those recipients which had received whole-body x-irradiation (8 Gy) just before cell transfer and intraperitoneally given soluble CII without adjuvant immediately after transfer. Non-immunized splenocytes could not induce arthritis even in irradiated recipients given soluble CII. Development of arthritis depended on the number of cells transferred; 5 x 10(7) cells induced severe and long-lasting arthritis in every recipient approximately 10 days after transfer. Severity of this arthritis was clinically and histologically similar to classical CA in donors. Arthritogenic splenocytes were generated in donors no later than 20 days after priming with CII in Freund's complete adjuvant, when arthritis had yet to occur, and were detected for more than 5 weeks. One splenocyte population responsible for transferring arthritis was CD4+ T cells. We then applied this system to show that prophylactic treatment of CII-immunized mice with cyclophosphamide (CY, 7 mg/kg), but not interferon-gamma (IFN-gamma, 10(5) U/mouse), suppressed the arthritogenic ability of their spleen cells, although both treatments inhibited the development of CA. Treatment of recipients with IFN-gamma, however, inhibited the development of arthritis upon transfer with CII-immunized splenocytes. These results indicate that CY and IFN-gamma act at the induction and effector phases of arthritogenic lymphocytes, respectively. Thus, this system facilitates investigation of pathological mechanisms of CA, and of mechanisms of anti-arthritics.