Effect of Bacillus Calmette-Guérin on immunosuppression from cyclophosphamide, methotrexate, and 5-fluorouracil.

SUMMARY Studies were undertaken to determine the effect of Bacil lus Calmette-Guërin (BCG) on the cellular and humonal response in mice receiving cyclophosphamide, methotnex ate, and 5-fluonouracil (CMF). C57BL/6 mice were given i.p. injections of sheep red blood cells and were grafted with BALB/c skin on Day 0. Treatment consisted of CMF, BCG, or both CMF and BCG. The number of plaque-forming spleen cells producing antibody against sheep red blood cells was measured on Days 5, 10, and 14. Skin grafts were evaluated frequently until complete rejection had occurred. The primary humoral response as measured by number of plaque-forming cells per 10@ nucleated spleen cells in mice treated with CMF on CMF and BCG was significantly me duced (p < 0.05) as compared to controls on Days 5, 10, and 14. The primary humonal response in mice treated with CMF and BCG was significantly reduced (p < 0.05) as compared to mice treated with CMF alone on Day 10. The secondary humonal response in mice treated with CMF on CMF and BCG was significantly reduced (p < 0.05) as compared to controls on Day 10. Cellular response as mea sumed by skingraft survival was not altered by CMF or by CMF and BCG, but it was increased significantly (p < 0.01) by BCG.