Engraftment of human central memory-derived effector CD8+ T cells in immunodeficient mice

Abstract

In clinical trials of adoptive T-cell therapy, the persistence of transferred cells correlates with therapeutic efficacy. However, properties of human T cells that enable their persistence in vivo are poorly understood, and model systems that enable investigation of the fate of human effector T cells (TE) have not been described. Here, we analyzed the engraftment of adoptively transferred human cytomegalovirus pp65-specific CD8+ TE cells derived from purified CD45RO+CD62L+ central memory (TCM) or CD45RO+CD62L- effector memory (TEM) precursors in an immunodeficient mouse model. The engraftment of TCM-derived effector cells (TCM/E) was dependent on human interleukin-15, and superior in magnitude and duration to TEM-derived effector cells (TEM/E). T-cell receptor Vβ analysis of persisting cells demonstrated that CD8+ T CM/E engraftment was polyclonal, suggesting that the ability to engraft is a general feature of TCM/E. CD8+ T EM/E proliferated extensively after transfer but underwent rapid apoptosis. In contrast, TCM/E were less prone to apoptosis and established a persistent reservoir of functional T cells in vivo characterized by higher CD28 expression. These studies predict that human CD8+ effector T cells derived from TCM precursors may be preferred for adoptive therapy based on superior engraftment fitness. © 2011 by The American Society of Hematology.