Blockade of IL-7R signaling by anti–IL-7Rα antibody can effectively prevent proliferation of an IL-7–dependent cell line. Antimurine IL-7Rα antibody purified from the ST185 hybridoma clone was tested for its ability to bind to IL-7Rα and block IL-7 signaling. (A) Lymph node CD4 and CD8 T cells from a BALB/c mouse were incubated in vitro with the anti–IL-7Rα antibody purified from the ST185 hybridoma supernatant. (B) To measure the effect of anti–IL-7Rα antibody on cell proliferation, the IL-7–dependent murine B-cell line, 2E8, was incubated in serum-free media with either nonspecific IgG or the anti-IL-7Rα antibody (100 ng/mL) for 30 minutes before IL-7 stimulation (12.5 pg/mL). For a negative control, the 2E8 cell line was incubated in media without IL-7 and IL-7Rα antibody. Cell proliferation was measured by determining the rate of 3H-thymidine incorporation into DNA for 24 hours after stimulation with or without IL-7. Asterisk indicates significant differences (P < .05) between PBS and anti–IL-7Rα antibody-treated groups.
