Fig 2.

Deleterious effect of antibiotics in a model of xenogeneic GVHD. Human mononuclear cells from peripheral blood were injected intravenously into NOD/SCID/γc−/− mice, 20 × 10⁶ cells per animal. Some of the mice (n = 20) were given ampicillin (1 mg/mL), clindamycin (1 mg/mL), vancomycin 1 mg/mL, and cefoperazone (0.5 mg/mL) in their drinking water. Control mice did not receive antibiotics (n = 10). The animals were monitored for diarrhea and weight loss and sacrificed when weight decreased 30% from the starting weight. The antibiotics in drinking water alone without the cell injection did not cause weight loss. The shown experiment is representative of 3 independent experiments. GVHD, graft-vs-host disease; PBMC, peripheral blood mononuclear cells.