title: B-cell-delivered gene therapy induces functional T regulatory cells and leads to a loss of antigen-specific effector cells.
abstract: Previous reports have shown that B-cell-mediated gene therapy can induce tolerance in several animal models for autoimmune diseases and inhibitory antibody formation in hemophilia A mice. We know from our previous work that the induction of tolerance following B-cell therapy is dependent upon CD25(+) regulatory T cells (Tregs). To extend these studies and identify the effects of this gene therapy protocol on the target CD4 T cells, we have adapted in vitro suppression assays using Tregs isolated from treated and control mice. Using carboxyfluorescein succinimidyl ester (CFSE) dilution as a measure of T-cell responsiveness to FVIII, we show that CD25(+) Tregs from treated mice are more suppressive than those from control animals. To monitor the induction of antigen-specific Tregs, we repeated these studies in ovalbumin (OVA) peptide-specific DO11.10 T-cell receptor (TCR) transgenic mice. Tregs from DO11.10 mice treated with a tolerogenic OVA-Ig construct are better than polyclonal Tregs at suppressing the proliferation of responder cells stimulated with OVA peptide 323-339 (pOVA). Furthermore, we show that following B-cell therapy, there is an increase in antigen-specific FoxP3(+) Tregs, and there is also a distinct decrease in antigen-specific CD4(+) effector T cells. These changes in the lymphocyte population shift the balance away from effector function toward a tolerogenic phenotype.
authors.affiliation: Center for Vascular and Inflammatory Diseases, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Skupsky
authors.forename: Ai-Hong
authors.initials: AH
authors.lastname: Zhang
authors.forename: Yan
authors.initials: Y
authors.lastname: Su
authors.forename: David W
authors.initials: DW
authors.lastname: Scott
mesh_terms: D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism; D002478:Cells, Cultured; D004195:Disease Models, Animal; D015316:Genetic Therapy / Q000379:methods*; D006467:Hemophilia A / Q000276:immunology / Q000628:therapy; D053645:Interleukin-2 Receptor alpha Subunit / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008817:Mice, Mutant Strains; D050378:T-Lymphocytes, Regulatory / Q000276:immunology* / Q000378:metabolism
chemical_list: D053645:Interleukin-2 Receptor alpha Subunit