Abstract
Mice were immunized with sheep red blood cells (SRBC) at day 0, and hemagglutinin (HA) titer of the serum, hemolytic plaque forming cells (HPFC) in the spleen cells and rosette forming cells (RFC) in both the spleen and thymus cells were assayed at day 5. The immune responses in the mice immunized with 1 ×108 SRBC intravenously were not affected by Y-12, 141 given orally for 5 days (0 ?? 4 days) at doses of 30 ?? 100 mg/kg, but were suppressed by cyclophosphamide (10 ?? 30 mg/kg p.o.) and D-penicillamine (100 mg/kg p.o.). The treatment of the mice with levamisole (1 ?? 30 mg/kg p.o.) resulted in the increase of RFC number in the spleen. Levamisole increased the number of RFC in the mice immunized with 5 ×106 ?? 108 SRBC. On the other hand, Y-12, 141 (10 ?? 30 mg/kg p.o.) increased spleen RFC number in the mice immunized with 5 ?? 10 × 106 SRBC. Y-12, 141 and levamisole given orally on day 0, 1 or 2 increased spleen RFC number in the mice immunized with 5 ×106 SRBC. D-Penicillamine given orally for 3 days (-2 ?? 0 days) also potentiated spleen rosette formation. The decreased number of RFC in the spleen and thymus by cyclophosphamide given orally in a dose of 20 mg/kg was restored by the treatment with Y-12, 141 (3 ?? 30 mg/kg) and levamisole (1 ?? 30 mg/kg). In addition, these agents suppressed 19S HA titer, and elevated 7S HA titer in the cyclophosphamide-treated mice. Prednisolone given orally in a dose of 30 mg/kg also decreased the number of RFC in the spleen. This decrease was restored by the treatment with Y-12, 141 and levamisole. These findings suggest that Y-12, 141 has a capacity to potentiate the immune response in mice immunized with low doses of SRBC and to restore the decrease of immune response caused by immunosuppressive drugs such as cyclophosphamide and prednisolone.
