Role of Regulatory T Cells in Tumor-Bearing Mice Treated with Allo-Hematopoietic Stem Cell Transplantation Plus Thymus Transplantation

Figure 1

Theory of allo-HSCT + TT. In the case of conventional allo-HSCT (a), allo-T_eff and T_reg cells develop, are tolerated, and react in the host thymus. No GVHD occurs. The proportion of T_reg cells is comparable to that in normal mice. In the case of allo-HSCT + DLI (c), allo-nontolerant T_eff and nonreactive T_reg cells are externally supplied, and strong GVHD is induced with reduction of T cell function. The proportion of T_reg cells is markedly decreased. In the case of allo-HSCT + TT, the allo-T_eff and T_reg cells develop internally in the allo-transplanted thymus. The T cells show partial tolerance and reaction with the host, and only mild GVHD occurs with elevation of T cell function (b). The proportion of T_reg cells decreases slightly. Figure 1 is modified from Hosaka [1], under the Creative Commons Attribution License/public domain.

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