Fichelson S, Chrétien S, Rokicka-Piotrowicz M, Bouhanik S, Gisselbrecht S, Mayeux P, Lacombe C
Laboratoire d'Hématopoïèse, Site Transfusionnel ETS, Hôpital Cochin, Institut National de la Transfusion Sanguine (INTS-GIP), 6 rue Alexandre Cabanel, Paris, F75015, France.
Biochem Biophys Res Commun. 1999 Mar 24;256(3):685-91. doi: 10.1006/bbrc.1999.0340.
To study the role of the cytoplasmic domain and particularly the tyrosine residues of the erythropoietin receptor (EpoR) in erythroid differentiation of human primary stem cells, we infected cord blood-derived CD34+ cells with retroviruses encoding chimeric receptors containing the extracellular domain of the prolactin receptor (PRLR) and the cytoplasmic domain of either the normal EpoR or a truncated EpoR devoid of tyrosine residues. Erythroid differentiation of the infected progenitors could thus be studied after stimulation by PRL. The complete PRLR was used to assess its ability to substitute for EpoR in erythroid differentiation. Typical erythroid day-14 colonies were observed from CD34+ cells grown in PRL when infected with any of the three viral constructs. These results demonstrate that: (i) the activation of the virally transduced PRLR leads to erythroid colony formation showing that erythroid terminal differentiation can be induced by a non-erythroid receptor in human progenitors; (ii) a chimeric receptor PRLR/EpoR is able to transduce a signal leading to terminal erythroid differentiation of human CD34+ cells; (iii) in contrast to results previously reported in murine models, tyrosine residues of the EpoR are not required for growth and terminal differentiation of human erythroid progenitors.
为了研究细胞质结构域尤其是促红细胞生成素受体（EpoR）的酪氨酸残基在人类原代干细胞红系分化中的作用，我们用编码嵌合受体的逆转录病毒感染脐带血来源的CD34+细胞，这些嵌合受体包含催乳素受体（PRLR）的胞外结构域和正常EpoR或不含酪氨酸残基的截短EpoR的细胞质结构域。因此，在催乳素刺激后，可以研究受感染祖细胞的红系分化。完整的PRLR用于评估其在红系分化中替代EpoR的能力。当用三种病毒构建体中的任何一种感染时，在催乳素中生长的CD34+细胞中观察到典型的第14天红系集落。这些结果表明：（i）病毒转导的PRLR的激活导致红系集落形成，表明人类祖细胞中的非红系受体可以诱导红系终末分化；（ii）嵌合受体PRLR/EpoR能够转导导致人类CD34+细胞终末红系分化的信号；（iii）与先前在小鼠模型中报道的结果相反，EpoR的酪氨酸残基对于人类红系祖细胞的生长和终末分化不是必需的。
