CD44 variant–specific antibodies stimulate adherent cells in LTBMCs to produce colony-forming activity.
(A) Where indicated, CD44 v4-, v6-, and v7-specific antibodies (10 μg/mL) were applied to adherent layers of LTBMCs (3 wells/group) in a transwell chamber. HSPCs, enriched by panning, were cultivated in the upper well at 37°C at a concentration of 106 cells/well. After 5 days of culture, the cells in the upper well of the transwell chambers were harvested and counted, and the numbers were expressed as means ± SD. (B) Conditioned media from 3 separate cultures of LTBMCs treated for 48 hours with CD44-specific antibodies, as indicated, were tested for GM-CSF by ELISA. (C) Conditioned media from LTBMCs (n = 3) treated for 48 hours with CD44-specific antibodies were tested for IL-6 by ELISA. Con indicates control antibody (10 μg/mL); pan, IM7 antibody (10 μg/mL). The experiment was repeated 3 times with similar results.
