CD26 expression on mobilized SKL cells and the effect of CD26 inhibition on HSPC mobilization and homing
| Mobilizer . | G-CSF . | GROβΔ4 . | G-CSF+GROβΔ4 . |
|---|---|---|---|
| MFI of CD26 on SKL cells | 22 ± 1 | 50 ± 4* | 17 ± 3** |
| CD26 pos. SKL cells/mL blood | 761 ± 83 | 1060 ± 46* | 1332 ± 127* |
| CD26 pos. SKL cells/2×106 MNC | 140 ± 15 | 262 ± 11* | 283 ± 27* |
| % homing of KL cells | 2.4 ± 0.6 | 4.6 ± 0.7 | ND |
| % homing of KL cells treated with Diprotin A | 4.3 ± 0.6† | 5.4 ± 0.9 | ND |
| % homing of SKL cells | 8.2 ± 0.9 | 13.5 ± 1.8* | ND |
| % homing of SKL cells treated with Diprotin A | 12.5 ± 1.6† | 14.5 ± 2.1 | ND |
| CFU-GM/mL blood in control mice | 1560 ± 480 | 2142 ± 954 | 5105 ± 991 |
| CFU-GM/mL blood in mice treated with Diprotin A | 944 ± 202‡ | 2413 ± 91 | 5378 ± 1440 |
| CFU-GM/mL blood in CD26+/+ mice | 3460 ± 211 | 1650 ± 263 | 4820 ± 683 |
| CFU-GM/mL blood in CD26−/− mice | 2415 ± 374‡ | 1510 ± 437 | 2214 ± 124‡ |
| Mobilizer . | G-CSF . | GROβΔ4 . | G-CSF+GROβΔ4 . |
|---|---|---|---|
| MFI of CD26 on SKL cells | 22 ± 1 | 50 ± 4* | 17 ± 3** |
| CD26 pos. SKL cells/mL blood | 761 ± 83 | 1060 ± 46* | 1332 ± 127* |
| CD26 pos. SKL cells/2×106 MNC | 140 ± 15 | 262 ± 11* | 283 ± 27* |
| % homing of KL cells | 2.4 ± 0.6 | 4.6 ± 0.7 | ND |
| % homing of KL cells treated with Diprotin A | 4.3 ± 0.6† | 5.4 ± 0.9 | ND |
| % homing of SKL cells | 8.2 ± 0.9 | 13.5 ± 1.8* | ND |
| % homing of SKL cells treated with Diprotin A | 12.5 ± 1.6† | 14.5 ± 2.1 | ND |
| CFU-GM/mL blood in control mice | 1560 ± 480 | 2142 ± 954 | 5105 ± 991 |
| CFU-GM/mL blood in mice treated with Diprotin A | 944 ± 202‡ | 2413 ± 91 | 5378 ± 1440 |
| CFU-GM/mL blood in CD26+/+ mice | 3460 ± 211 | 1650 ± 263 | 4820 ± 683 |
| CFU-GM/mL blood in CD26−/− mice | 2415 ± 374‡ | 1510 ± 437 | 2214 ± 124‡ |
Means (± SEM) are shown. Lineage-depleted cells mobilized by G-CSF, GROβΔ4, or G-CSF+GROβΔ4 were stained with Sca-1-PE, c-kit-APC, and CD26-FITC (clone H194-112, BD Biosciences) and analyzed for CD26 expression on SKL cells by flow cytometry. Mean fluorescent intensity (MFI) of CD26 is shown. The number of CD26+-SKL cells in blood and in 2 × 106 mononuclear cells was calculated by the percentage of CD26-positive cells multiplied by the number of SKL cells/mL blood and SKL cells/2 × 106 mononuclear cells. To determine homing of mobilized HSPCs, cells were treated with or without 5 mM Diprotin A for 15 minutes and washed before transplantation as described.13 Homing of KL and SKL cells were determined as described in Table 2. CFU-GM mobilization was compared in mice treated with Diprotin A (Peptides International, Louisville, KY) 2 times/day for 4 days as reported62 and CD26−/− mice, kindly provided by Dr Hal E. Broxmeyer, Indiana University School of Medicine, with control mice.
ND indicates not done.
P < .05 compared with G-CSF.
P < .05 compared with GROβΔ4 (N = 4).
P < .05 compared with nontreated mice (N = 6).
P < .05 compared with control wild-type mice.