RÉSUMÉ
The study was aimed to explore the influence of co-culture ex vivo of CD34+ cells from two units of cord blood (CB) on the homing-related adherent molecule expression of each other. Mesenchymal stem cells (MSCs) were obtained from human bone marrow. Two units of CB CD34+ cells were co-cultured on 12 Gy gamma-ray irradiated MSC layer. Their adherent molecule expressions were assessed by flow cytometry. The results showed that the purity of the isolated CD34+ cells was (98.25+/-0.93)%. After co-culture on MSC layer for 6 days, the proportion of CD34+ cells of each unit was dropped to (60.4+/-6.32)% and (60.2+/-5.12)% respectively, but there was no significant difference from the control groups. The expressions of CD44, CD62L, CD184 and CD26 on CD34+ cells of each unit remained unaffected. The expression of CD162 was downregulated and CD54 was first increased but then dropped to the level before co-culture. But there was no significant difference between the experimental and control groups. In conclusion, co-culture of CD34+ cells from two units of CB may have no effects on the adherent molecule expressions of each other.