underlie enhanced Th1 immunity caused by immunization ... activated autologous T cells leads to enhanced anti-tumor immunity and ... tumor treatment [14].
ORIGINAL ARTICLE
Qi Cao et al. npg Cell Research (2007) 17:627-637. 627 npg © 2007 IBCB, SIBS, CAS All rights reserved 1001-0602/07 $ 30.00 www.nature.com/cr
Downregulation of CD4+CD25+ regulatory T cells may underlie enhanced Th1 immunity caused by immunization with activated autologous T cells Qi Cao1, 2, *, Li Wang1, 2, *, Fang Du1, 2, Huiming Sheng1, 2, Yan Zhang1, 2, Juanjuan Wu1, 2, Baihua Shen1, 2, Tianwei Shen1, 2, Jingwu Zhang1, 2, Dangsheng Li3, Ningli Li1, 2 Department of Immunology, Shanghai Jiao Tong University School of Medicine, Shanghai, China; 2Shanghai Institute of Immunology, 280 South Chongqing Road, Shanghai 200025, China; 3Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China 1
Regulatory T cells (Treg) play important roles in immune system homeostasis, and may also be involved in tumor immunotolerance by suppressing Th1 immune response which is involved in anti-tumor immunity. We have previously reported that immunization with attenuated activated autologous T cells leads to enhanced anti-tumor immunity and upregulated Th1 responses in vivo. However, the underlying molecular mechanisms are not well understood. Here we show that Treg function was significantly downregulated in mice that received immunization of attenuated activated autologous T cells. We found that Foxp3 expression decreased in CD4+CD25+ T cells from the immunized mice. Moreover, CD4+CD25+Foxp3+ Treg obtained from immunized mice exhibited diminished immunosuppression ability compared to those from naïve mice. Further analysis showed that the serum of immunized mice contains a high level of anti-CD25 antibody (about 30 ng/ml, p
