Studies on the homing-related adhesion activities of UCB HSPC in short-term ex vivo expansion / 中华血液学杂志

ABSTRACT

<p><b>OBJECTIVE</b>To study the effect of ex vivo expansion on the adhesion activities of umbilical cord blood hematopoietic stem and progenitor cells (HSPC).</p><p><b>METHODS</b>Fresh UCB CD(34)(+) cells were cultured in a serum and stroma-free culture system. At day 7, day 10 and day 14, CD(34)(+) cells were re-selected from the expanded products. The expression of adhesion molecules (CAMs) such as VLA-4, VLA-5, LFA-1, ICAM-1, HCAM, L-selectin and PECAM-1, and the adhesion activity of the expanded CD(34)(+) cells were evaluated and compared with those of precultured fresh CD(34)(+) cells.</p><p><b>RESULTS</b>(1) The CD(34)(+) cells expressing homing-related CAMs were increased (from 15-fold increase for CD(34)(+) CD(54)(+) subset to 72-fold increase for CD(34)(+) CD(49e)(+) subset at day 14). (2) The expressions of CD(49d), CD(44), CD(11a) and CD(49e) on the expanded CD(34)(+) cells were increased or sustained the same levels as those on fresh UCB CD(34)(+) cells, while the expression of CD(62L), CD(54) and CD(31) on expanded CD(34)(+) cells declined with the cultivating. (3) Spontaneous adhesion and SDF-1-induced adhesion tended to be increased in the course of the first 10 day's culture.</p><p><b>CONCLUSIONS</b>The culture system used in this study could substantially support the expansion of HSPCs expressing the above CAMs, and the expanded HSPCs would sustain their intrinsic adhesion potentials.</p>