A kinetic and dynamic analysis of Foxp3 induced in T cells by TGF-beta.
TGF-beta induces Foxp3 expression in stimulated T cells. These Foxp3+ cells (induced regulatory T cells (iTreg)) share functional and therapeutic properties with thymic-derived Foxp3+ regulatory T cells (natural regulatory T cells (nTreg)). We performed a single-cell analysis to better characterize the regulation of Foxp3 in iTreg in vitro and assess their dynamics after transfer in vivo. TGF-beta up-regulated Foxp3 in CD4+Foxp3- T cells only when added within a 2- to 3-day window of CD3/CD28 stimulation. Up to 90% conversion occurred, beginning after 1-2 days of treatment. Foxp3 expression strictly required TCR stimulation but not costimulation and was independent of cell cycling. Removal of TGF-beta led to a loss of Foxp3 expression after an approximately 4-day lag. Most iTreg transferred into wild-type mice down-regulated Foxp3 within 2 days, and these Foxp3- cells were concentrated in the blood, spleen, lung, and liver. Few of the Foxp3- cells were detected by 28 days after transfer. However, some Foxp3+ cells persisted even to this late time point, and these preferentially localized to the lymph nodes and bone marrow. CXCR4 was preferentially expressed on Foxp3+ iTreg within the bone marrow, and CD62L was preferentially expressed on those in the lymph nodes. Like transferred nTreg and in contrast with revertant Foxp3- cells, Foxp3+ iTreg retained CD25 and glucocorticoid-induced TNFR family-related gene. Thus, Foxp3 expression in naïve-stimulated T cells is transient in vitro, dependent on TGF-beta activity within a highly restricted window after activation and continuous TGF-beta presence. In vivo, a subset of transferred iTreg persist long term, potentially providing a lasting source for regulatory activity after therapeutic administration.
Selvaraj
Ramesh K
RK
Department of Pathology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA.
Geiger
Terrence L
TL
D019264:Adoptive Transfer; D000818:Animals; D002454:Cell Differentiation / Q000276:immunology; D002465:Cell Movement / Q000276:immunology; D049109:Cell Proliferation; D002470:Cell Survival / Q000276:immunology; D002478:Cells, Cultured; D005434:Flow Cytometry; D051858:Forkhead Transcription Factors / Q000276:immunology* / Q000378:metabolism*; D007108:Immune Tolerance; D008213:Lymphocyte Activation / Q000276:immunology; D051379:Mice; D016176:T-Lymphocyte Subsets / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D050378:T-Lymphocytes, Regulatory / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000276:immunology* / Q000378:metabolism
D051858:Forkhead Transcription Factors; C498833:Foxp3 protein, mouse; D016212:Transforming Growth Factor beta