Fig. 1.
LTC-IC maintenance in the presence of HS with IL-3 and MIP-1.
A total of 10 000 to 20 000 DR− cells were plated in 0.4-μm transwell inserts in 6-well tissue culture clusters. Medium in the lower chambers of the wells was replaced daily by either stroma-conditioned medium (Stroma CM) or long-term bone marrow culture (LTBMC) medium supplemented with or without 5 μg/mL HS. A total of 5 ng/mL IL-3 and 10 ng/mL MIP-1α were added to all cultures, including Stroma CM. Cultures were harvested after 2 weeks (A) or 5 weeks (B) and cells replated at limiting dilutions for estimation of LTC-IC frequency, as described in Methods. Numbers within the bars indicate the number of experiments. Comparison between LTBMC medium only and other conditions: *P < .005.