Fig. 3.
Eosinophils predominate in the DTH reaction following vaccination with MFG-GM-CSF-transduced vaccines. Representative H&E-stained sections of posttreatment DTH biopsies of mice vaccinated with untransduced irradiated B16 melanoma vaccine (A) are compared with those transfected with MFG-GM-CSF vector secreting GM-CSF at 360 ng/106 cells/24 h (C), autologous irradiated human RCC (B), and irradiated RCC transduced with MFG-GM-CSF (D). For both murine and human DTH tests, the cell preparations, including freezing in fetal bovine serum, irradiation, and cell innocula, were equivalent. Eosinophils were quantitated as described in “Patients and Methods” for intradermal biopsies. Three eosinophils/200× hpf were seen in the DTH site of patient vaccinated with nontransduced RCC and 588 eosinophils/200× hpf in the DTH site of patient vaccinated with GM-CSF-transduced RCC. ×400.