[Factors determining prolonged chimerism of lymphoid tissue in mice treated with cyclophosphamide]

Conditions of long-lasting chimerism induction in adult CBA mice treated with cyclophosphamide and spleen cells (CBAXC57BL/6)F1 were investigated. The necessary requirements are high cell doses (over 50X10(6)), cyclophosphamide dose equal or over 200 mg/kg and a short interval (3-6hr) between their injections. The data obtained were interpreted from the point of view of the capacity of cyclophosphamide to induce reversible lymphocyte DNA damages. After the interaction of lymphocytes with the antigen these damages are fixed with the resultant elimination of the corresponding cell clone.