Critical, but conditional, role of OX40 in memory T cell-mediated rejection

Minh Diem Vu, Michael R. Clarkson, Hideo Yagita, Laurence A. Turka, Mohamed H. Sayegh, Xian Chang Li

Research output: Contribution to journalArticlepeer-review

106 Scopus citations


Memory T cells can be a significant barrier to the induction of transplant tolerance. However, the molecular pathways that can regulate memory T cell-mediated rejection are poorly defined. In the present study we tested the hypothesis that the novel alternative costimulatory molecules (i.e., ICOS, 4-1BB, OX40, or CD30) may play a critical role in memory T cell activation and memory T cell-mediated rejection. We found that memory T cells, generated by either homeostatic proliferation or donor Ag priming, induced prompt skin allograft rejection regardless of CD28/GD154 blockade. Phenotypic analysis showed that, in contrast to naive T cells, such memory T cells expressed high levels of OX40, 4-1BB, and ICOS on the cell surface. In a skin transplant model in which rejection was mediated by memory T cells, blocking the OX40/OX40 ligand pathway alone did not prolong the skin allograft survival, but blocking OX40 costimulation in combination with CD28/CD154 blockade induced long-term skin allograft survival, and 40% of the recipients accepted their skin allograft for >100 days. In contrast, blocking the ICOS/ICOS ligand and the 4-1BB/4-1BBL pathways alone or combined with CD28/CD154 blockade had no effect in preventing skin allograft rejection. OX40 blockade did not affect the homeostatic proliferation of T cells in vivo, but markedly inhibited the effector functions of memory T cells. Our data demonstrate that memory T cells resisting to CD28/CD154 blockade in transplant rejection are sensitive to OX40 blockade and suggest that OX40 is a key therapeutic target in memory T cell-mediated rejection.

Original languageEnglish (US)
Pages (from-to)1394-1401
Number of pages8
JournalJournal of Immunology
Issue number3
StatePublished - Feb 1 2006

ASJC Scopus subject areas

  • Immunology and Allergy
  • Immunology


Dive into the research topics of 'Critical, but conditional, role of OX40 in memory T cell-mediated rejection'. Together they form a unique fingerprint.

Cite this