The agonist antihuman gp130 MoAb does not recognize or activate murine gp130. Human XG-1 (A) and murine B9 hybridoma (B) cells were extensively washed and cultured at 5 × 104cells/mL (XG-1) or 3 × 104 cells/mL (B9) with 10 μg/mL of control murine IgG1 (control) or with 3 ng/mL (XG-1) or 20 pg/mL (B9) of IL-6 or with 10 μg/mL of a mixture of B-S12 and B-P8 (5 μg each) antihuman gp130 IL-6 transducer MoAbs. Every 5 days, the cells were counted and cultures were diluted at the initial cell concentration with culture medium containing fresh cytokine or the initial concentration of anti-gp130 MoAb. Results are the cumulative numbers of cells generated in the cultures. XG-1 (C) or B9 (D) cells were labeled with biotinylated B-S12 or B-P8 MoAb or control biotinylated murine IgG1 and then with FITC-conjugated avidin. Results are the fluorescence profiles obtained with the different antibodies analyzed with a FACSCAN apparatus.
