Characterization of cyclophosphamide-induced suppressor cells

Abstract

Spleen cells from mice injected with cyclophosphamide (200 mg/kg body weight) suppress the secondary immunoglobulin (IgG antibody response of memory cells to a T-dependent antigen, dinitrophenylated (DNP) human gamma globulin, in Millipore diffusion chambers. Characterization of the suppressor cell revealed that it was nylon wool nonadherent, insensitive to treatment with anti-Thy 1.2 or anti-Ig serum plus C, found in spleen but not thymus or lymph nodes, generated in thymectomized mice and nude mice, and heart sensitive. Because of these unique characteristics, it was concluded that the suppressor cell was not a typical B cell, T cell, or macrophage. The suppressor cell was found to be regulated, i.e., inhibited, by a T cell found in the thymus and possibly the lymph nodes of normal mice. The suppressor cells may have biological significance in relation to development of self-tolerance.