摘要
Several subsets of T-regulatory （Tr） cells with distinct phenotypes and distinct mechanisms of action have been identified. These include Tr type 1 （Trl） cells; Th3 cells, which primarily secrete transforming growth factor （TGF）-β; and CD4^＋CD25^＋ T cells, which inhibit immune responses through cell to cell contact.1 It has been shown that CD4^＋CD25^＋ immunoregulatory T cells induced by the blockade of CD154-CD40 pathway are tolerant to alloantigen, resulting in secondary mixed lymphocyte reaction （MLR） hyporesponsiveness in vitro and tolerance to alloantigen in vivo. Previous studies mainly paid attention to CD4^＋CD25^＋ immunoregulatory T cells induced by CD154-CD40 blockade, but it was unclear whether CD154-CD40 blockade might induce Trl or Tr1-like cells.
Several subsets of T-regulatory （Tr） cells with distinct phenotypes and distinct mechanisms of action have been identified. These include Tr type 1 （Trl） cells; Th3 cells, which primarily secrete transforming growth factor （TGF）-β; and CD4^＋CD25^＋ T cells, which inhibit immune responses through cell to cell contact.1 It has been shown that CD4^＋CD25^＋ immunoregulatory T cells induced by the blockade of CD154-CD40 pathway are tolerant to alloantigen, resulting in secondary mixed lymphocyte reaction （MLR） hyporesponsiveness in vitro and tolerance to alloantigen in vivo. Previous studies mainly paid attention to CD4^＋CD25^＋ immunoregulatory T cells induced by CD154-CD40 blockade, but it was unclear whether CD154-CD40 blockade might induce Trl or Tr1-like cells.
