Survival and proliferation of Lin⁻c-kit⁺ hematopoietic progenitors in Rab-9 cocultures.

(A) Growth curves of nonadherent hematopoietic cells in Rab-9 cocultures. This experiment is similar to that described in Figure 6except that Lin⁻ c-kit⁺ cells (3000 per well) were used. Cell numbers have been corrected for subculture ratios and represent means of duplicate measurements. Open circle, LXSN; filled circle, LMJSN. (B) Results of colony assays performed on nonadherent cells harvested from the cocultures on day 8, 16, 24, and 28. Cells were plated in methylcellulose culture medium supplemented with SCF, IL-3, and GM-CSF. Data are expressed as the ratios of total CFCs (HPP-CFC, CFU-GM, CFU-G, and CFU-M combined) recovered from Rab-9/LMJSN cocultures to those recovered from Rab-9/LXSN cocultures. At each assay point, the total number of CFC recovered from Rab-9/LXSN coculture is treated as 1. Results are means of triplicates.