Preferential migration of CD34⁺CD117⁺ cells with the D816V mutation.

(A) A schematic diagram of the HinfI restriction sites in the 111-bp PCR product from HMC-1.1 and HMC-1.2 control cell lines. Predicted sizes for the sequence from the wild-type control cell line HMC-1.1 (without the kit D816V mutation) are 68 and 43 bp and for the positive control cell line HMC-1.2 (heterozygous for the Kit D816V mutation) are 68, 54, 43, and 14 bp. (B) RepresentativeHinfI restriction digestion and quantification by gel fluorescence imaging of the D816V mutation in CD34⁺CD117⁺ cells obtained from a patient with mastocytosis compared to control cell lines HMC-1.1 (wt) and HMC-1.2 (D816V) (the 14-bp band is not shown in this figure). CD34⁺CD117⁺ cells were harvested after 1 and 3 days of culture and analyzed for the D816V mutation in the starting population and in the bottom chamber at 3 and 6 hours following chemotaxis to SCF (10 ng/mL). An experiment using cells from a second patient yielded similar results. The percent total cell migration for each population was HMC1.2, 7.5%; HMC1.1, 5.7%; CD34⁺CD117⁺, day 1, 3 hours, 6.5%; CD34⁺CD117⁺, day 1, 6 hours, 8%; CD34⁺CD117⁺, day 3, 3 hours, 6.3%; CD34⁺CD117⁺, day 3, 6 hours, 13.8%.