COMPARATIVE-STUDY OF CYCLOPHOSPHAMIDE, 6-MERCAPTOPURINE, AZATHIOPURINE AND METHOTREXATE - RELATIVE EFFECTS ON HUMORAL AND CELLULAR IMMUNE-RESPONSE IN MOUSE

Abstract

The effects of cyclophosphamide, methotrexate, azathioprine and 6-mercaptopurine on the concomitant development of the humoral and the cellular immune responses of mice to a single antigen, the El4 [leukemia] tumor cell, were investigated. The measurements of cellular and humoral immunity were carried out in the same animal using lymphocyte and antibody mediated lysis of the El4 cell, a measurement system independent of underlying anti-inflammatory effects. A regimen of daily cyclophosphamide had a more pronounced suppressive effect on the humoral response than on the cellular response. A single low dose of cyclophosphamide stimulated the cellular response and suppressed the humoral response. Single or multiple high doses of cyclophosphamide maximally suppressed the cellular and humoral response. Azathioprine and 6-mercaptopurine caused equivalent inhibition of the humoral and cellular responses, and thus lacked selectivity. Methotrexate also provided equivalent inhibition of the humoral and cellular responses at all dose levels investigated.