Changes in lymphocyte subsets following administration of interleukin 2 and cyclophosphamide in mice with transitional cell carcinoma.

We investigated the effects of combination therapy with interleukin 2(IL-2) and cyclophosphamide (CPM) in C3H/HeN mice implanted with mouse bladder tumor cells (MBT2). Tumor growth was suppressed in the mice treated with IL-2 alone and mice treated with CPM alone, although not completely. However, tumor growth was completely suppressed in the mice treated with both IL-2 and CPM. As for lymphocyte subset analysis of the spleen using flow cytometry, the frequency of Lyt2+ cells and asialo GM1+ cells was significantly higher in the mice treated with IL-2 and CPM compared to the other groups. In the lymphocyte subset analysis of the thymus, the frequency of L3T4-Lyt2+ cells was significantly lower in the mice treated with CPM alone and mice treated with IL-2 and CPM compared to the other groups.