Loss of FOXP3 Expression and Emergence of Cytokine-Producing Cells after In Vitro Expansion of Human CD4+CD25+CD127 - Regulatory T Cells.

摘要: We and others previously showed that the adoptive transfer of donor-type CD4+CD25+ regulatory T (Treg) cells protects from graft-versus-host disease (GVHD) after allogeneic stem cell transplantation (SCT) in animal models. Exploring this strategy human SCT, we currently perform a first Phase I clinical trial using freshly isolated Treg cells. For future trials requiring large numbers for repetitive treatments, described vitro culture conditions permit more than 3-log expansion polyclonal (Blood 104:895; 2004). A highly enriched starting population proved to be crucial generation pure products could show naive, CD45RA+ subpopulation CD4+CD25high fulfills criterion (Blood108:4260; 2006). recently proposed alternative approach isolation relies on exclusion CD127+ cells, as activated (i.e. CD25+) conventional express high levels CD127 while no or only weak expression (Seddiki et al. Liu al., JEM203:1693; To directly compare these two approaches, CD4+CD25+CD127low/neg (CD127-Treg) CD45RA+CD4+CD25high (RA+ Treg) same leukapheresis analyzed 2 3 weeks expansion. Whereas both populations were > 94% FOXP3+ upon isolation, RA+ maintained level throughout period (93% (range: 78 97%; n=11) 87% 71 n=9) weeks). In contrast, proportion CD127-Treg cultures was already reduced (82% 56 96%; n=11)) variable significantly lower (57% 18 93%; n=9; p=0.006)). When further subdivided into CD45RA- subpopulations before expansion, CD45RA-CD127-Treg lost FOXP3 comprised substantial FOXP3- cytokine producing (on average 54% 38% IL-2 IFN-γ producers, respectively) weeks, whereas CD127- behaved similar they over time contained low producers. Furthermore, when DNA methylation status found Treg-specific CpG demethylation pattern within gene (EJI 37, 2007) lines, increased even so RA- cultures. Based findings, suggest at present represents best therapies expanded