Department of Immunohematology and Blood Transfusion, Leiden University Medical Center, Leiden, The Netherlands.
Blood. 2012 Jul 19;120(3):505-10. doi: 10.1182/blood-2012-02-410571. Epub 2012 May 24.
Umbilical cord blood (UCB) is used for HSCT. It is known that UCB can comprise Ag-specific T cells. Here we question whether solely transmaternal cell flow may immunize UCB. Twenty-three female UCB samples were collected from healthy mothers and analyzed for minor histocompatibility Ag HY-specific responses. Forty-two of 104 tetramer(pos) T-cell clones, isolated from 16 of 17 UCB samples, showed male-specific lysis in vitro. Male microchimerism was present in 6 of 12 UCB samples analyzed. In conclusion, female UCB comprises HY-specific cytotoxic T cells. The immunization is presumably caused by transmaternal cell flow of male microchimerism present in the mother. The presence of immune cells in UCB that are not directed against maternal foreign Ags is remarkable and may explain the reported clinical observation of improved HSCT outcome with younger sibling donors.
脐带血（UCB）用于 HSCT。已知 UCB 可包含 Ag 特异性 T 细胞。在这里，我们质疑仅经母体细胞流动是否可使 UCB 免疫。从健康母亲中采集了 23 份 UCB 样本，并对其进行了针对次要组织相容性 Ag HY 的特异性反应分析。从 17 个 UCB 样本中的 16 个中分离出的 104 个四聚体（pos）T 细胞克隆中，有 42 个在体外显示出男性特异性裂解。在分析的 12 个 UCB 样本中，有 6 个存在男性微嵌合体。总之，女性 UCB 包含 HY 特异性细胞毒性 T 细胞。免疫可能是由母亲中存在的男性微嵌合体的经母体细胞流动引起的。UCB 中存在不针对母体外来 Ag 的免疫细胞是值得注意的，这可能解释了报道的用年轻同胞供体进行 HSCT 可获得更好结果的临床观察。
