Human prostate tumor antigen-specific CD8+ regulatory T cells are inhibited by CTLA-4 or IL-35 blockade.

ABSTRACT: Regulatory T cells play important roles in cancer development and progression by limiting the generation of innate and adaptive anti-tumor immunity. We hypothesized that in addition to natural CD4(+)CD25(+) regulatory T cells (Tregs) and myeloid-derived suppressor cells, tumor Ag-specific Tregs interfere with the detection of anti-tumor immunity after immunotherapy. Using samples from prostate cancer patients immunized with a DNA vaccine encoding prostatic acid phosphatase (PAP) and a trans-vivo delayed-type hypersensitivity (tvDTH) assay, we found that the detection of PAP-specific effector responses after immunization was prevented by the activity of PAP-specific regulatory cells. These regulatory cells were CD8(+)CTLA-4(+), and their suppression was relieved by blockade of CTLA-4, but n

SUBMITTER: Olson BM 

PROVIDER: S-EPMC3735346 | biostudies-literature | 2012 Dec

REPOSITORIES: biostudies-literature