IgG protein expression of MedB-1 cells.

In comparison with the IgG⁻ parental tumor (A), a small subset of MedB-1 cells showed an expression of IgG protein, detectable by immunocytochemistry (B) and ELISA (F). Incubation for 48 hours in the presence of 100 U/mL IL-4 resulted in a down-regulation of IgG (C, F) whereas 10 μg/mL dexamethasone induced a moderate increase (D, F). ELISA data are given as mean value (no. = 5) and SD. Panel E shows negative control pancreatic carcinoma cell line MiaPaca. Original magnification ×50 (A), and ×100 (B-E).