Effect of fractional cyclophosphamide dosage on sheep red blood cell-delayed-type hypersensitivity response in mice.
The CY-enhancing effect on DTH response of mice against SRBC was studied by administering to sensitized animals graded amounts of drug at various times during the immune response. The use of a staggered schedule for CY administration made it clear that this enhancing effect could be augmented even further by lowering the standard 200 mg/kg CY dose. Animals immunized on day 0 with 1 X 10(8) SRBC receiving 50 mg/kg doses on days -1, +1, and +4 showed higher DTH responses on day +7 than those similarly sensitized 1 day after the administration of 200 mg/kg body weight. In addition, we wanted to demonstrate that the TDTH effector cell is sensitive to CY in vivo, because a single 50 mg/kg dose inoculated on day +6 can lower by 50% an already established DTH response. This effect was not due to an effect of CY treatment on bone marrow-derived cells recruited to DTH responses; inhibition of DTH responses were transferred with spleen cells of CY-treated recipients. The action of CY is not dose-dependent; the administration on day +6 of a single dose of 200 mg/kg results in no further depression of the DTH reaction. We conclude that CY affects not only T supp cells, but also cell type(s) involved in the cell-mediated response of mice against SRBC, and that the DTH-enhancing effect of the drug is a blend of its action upon all these cells.
D000276:Adjuvants, Immunologic / Q000008:administration & dosage*; D000818:Animals; D003520:Cyclophosphamide / Q000008:administration & dosage*; D004306:Dose-Response Relationship, Immunologic; D004912:Erythrocytes / Q000276:immunology; D005260:Female; D006968:Hypersensitivity, Delayed / Q000276:immunology*; D007116:Immunization, Passive; D007519:Isoantigens / Q000008:administration & dosage*; D017710:Lymphocyte Transfusion; D008214:Lymphocytes / Q000276:immunology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D012756:Sheep; D050378:T-Lymphocytes, Regulatory / Q000276:immunology / Q000637:transplantation; D013997:Time Factors
D000276:Adjuvants, Immunologic; D007519:Isoantigens; D003520:Cyclophosphamide