Arlettaz L, Barbey C, Dumont-Girard F, Helg C, Chapuis B, Roux E, Roosnek E
Division of Immunology and Allergology Department of Internal Medicine, University Hospital, Geneva, Switzerland.
Eur J Immunol. 1999 Dec;29(12):3987-94. doi: 10.1002/(SICI)1521-4141(199912)29:12<3987::AID-IMMU3987>3.0.CO;2-4.
We have studied the alterations in CD45R phenotypes of CD4(+)CD45RA(-)RO(+) T cells in recipients of T cell-depleted bone marrow grafts. These patients are convenient models because early after transplantation, their T cell compartment is repopulated through expansion of mature T cells and contains only cells with a memory phenotype. In addition, re-expression of CD45RA by former CD4(+)CD45RA(-) T cells can be accurately monitored in the pool of recipient T cells that, in the absence of recipient stem cells, can not be replenished with CD45RA(+) T cells through the thymic pathway. We found that CD4(+)CD45RA(-)RO(+) recipient T cells could re-express CD45RA but never reverted to a genuine CD4(+)CD45RA(+)RO(-) naive phenotype. Even 5 years after transplantation, they still co-expressed CD45RO. In addition, the level of CD45RA and CD45RC expression was lower ( approximately 35 %) than that of naive cells. In contrast, the level of CD45RB expression was comparable to that of naive cells. We conclude that CD4(+)CD45RA(-)RO(+) T cells may re-express CD45(high) isoforms but remain distinguishable from naive cells by their lower expression of CD45RA / RC and co-expression of CD45RO. Therefore, it is likely that the long-lived memory T cell will be found in the population expressing both low and high molecular CD45 isoforms.
我们研究了T细胞去除的骨髓移植受者中CD4(+)CD45RA(-)RO(+) T细胞的CD45R表型变化。这些患者是便利的模型，因为移植后早期，其T细胞区室通过成熟T细胞的扩增而重新填充，并且仅包含具有记忆表型的细胞。此外，在受体T细胞池中可以准确监测前CD4(+)CD45RA(-) T细胞CD45RA的重新表达，在没有受体干细胞的情况下，不能通过胸腺途径用CD45RA(+) T细胞补充该池。我们发现，CD4(+)CD45RA(-)RO(+)受体T细胞可以重新表达CD45RA，但从未恢复到真正的CD4(+)CD45RA(+)RO(-)幼稚表型。即使在移植后5年，它们仍共表达CD45RO。此外，CD45RA和CD45RC的表达水平低于幼稚细胞（约35%）。相比之下，CD45RB的表达水平与幼稚细胞相当。我们得出结论，CD4(+)CD45RA(-)RO(+) T细胞可能重新表达CD45（高）异构体，但通过其较低的CD45RA / RC表达和CD45RO的共表达仍可与幼稚细胞区分开来。因此，在表达高分子量和低分子量CD45异构体的群体中可能会发现长寿记忆T细胞。
