CD45 isoform phenotypes of human T cells: CD4(+)CD45RA(-)RO(+) memory T cells re-acquire CD45RA without losing CD45RO

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Bone Marrow Transplantation
  • CD4 Antigens / immunology
  • Humans
  • Immunologic Memory / genetics
  • Immunologic Memory / immunology*
  • Leukocyte Common Antigens / genetics
  • Leukocyte Common Antigens / immunology*
  • Male
  • Protein Isoforms / genetics
  • Protein Isoforms / immunology
  • T-Lymphocytes / immunology*
  • Transplantation Immunology


  • CD4 Antigens
  • Protein Isoforms
  • Leukocyte Common Antigens