Resting B cells as Inducers of Antigen-Specific T Regulatory Cells (83.22)

Abstract

Abstract We have previously shown that resting B cells are able to expand T regulatory cells through TGF-beta3 whereas activated B cells induce increased apoptosis of T regulatory cells. Thus, we hypothesize that resting B cells can be used to induce antigen-specific T regulatory cells. To test our hypothesis, we isolate resting B cells from mice and load the cells with Ova, and then adoptively transfer the B cells to Ova-specific TCR transgenic mice. We determine numbers of OVA-specific T effector cells and T regulatory cells in the adoptively transferred mice and in control mice that receive untreated resting B cells alone by flow cytometry (Foxp3). We further determine if these T regulatory cells mediate immunosuppressive activities by using proliferation assay in vitro and by in vivo prevention of immune response against challenge with OVA + adjuvant. This study will provide basis to develop approaches to induce antigen-specific T regulatory cells to treat inflammatory diseases such as allergy and autoimmune diseases.