T cell sensitivity to TGF-  is required for the effector function but not the generation of splenic CD8+ regulatory T cells induced via the injection of antigen into the anterior chamber

This is the authors' abstract. We don't add key points for this paper.

The introduction of antigen into the anterior chamber (AC) of the eye induces the production of antigen-specific splenic CD8(+) regulatory T cells (AC-SPL cells) that suppress a delayed-type hypersensitivity (DTH) reaction in immunized mice. Because the generation of these regulatory T cells is also induced by exposure to transforming growth factor (TGF)-beta and antigen or F4/80(+) cells exposed to TGF-beta and antigen in vitro, we investigated (i) whether these cells are produced in dominant negative receptor for transforming growth factor beta receptor type II (dnTGFbetaRII) or Cbl-b(-/-) mice whose T cells are resistant to TGF-beta, (ii) whether DTH is suppressed by wild type (WT) CD8(+) AC-SPL cells in Cbl-b(-/-) and dnTGFbetaRII mice and (iii) the effect of antibodies to TGF-beta on the suppression of DTH by CD8(+) AC-SPL cells. DnTGFbetaRII immunized and Cbl-b(-/-) mice produced splenic CD8(+) regulatory cells after the intracameral injection of antigen and immunization. The suppression of a DTH reaction by CD8(+) AC-SPL cells in WT mice was blocked by the local inclusion of antibodies to TGF-beta when WT splenic CD8(+) AC-SPL cells were injected into the DTH reaction site. Moreover, the DTH reaction in immunized dnTGFbetaRII and Cbl-b(-/-) mice was not suppressed by the transfer of WT CD8(+) AC-SPL cells to the site challenged with antigen. In aggregate, these observations suggest that T cell sensitivity to TGF-beta is not an obligate requirement for the in vivo induction of CD8(+) AC-SPL T cells but the suppression of an in vivo DTH reaction by CD8(+) AC-SPL cells is dependent on TGF-beta.