Dendritic cells and B cells cooperate in the generation of CD4(+)CD25(+)FOXP3(+) allogeneic T cells.
BACKGROUND
CD4(+)CD25(+)Foxp3(+) regulatory T cells (Treg) play an essential role in immune tolerance, suppressing responses against self-antigens. Additionally, Treg play an important role in maintaining immunosuppression to alloantigens as well as to other antigens. It is well known that in the gut, a subset of dendritic cells produces retinoic acid (RA), which together with transforming growth factor (TGF-beta) is able to differentiate naïve T cells into Treg. The aim of this study was to establish the role of antigen-presenting cells (APC) in the differentiation of allogeneic Tregs under the effect of RA and TGF-beta.


METHODS
Splenic CD4(+)CD25(-) naïve T cells from C57BL/6 mice were co-cultured with splenic CD11c-enriched APC from Balb/c mice in the presence of TGF-beta, RA, and interleukin (IL-2). After 6 days of culture, cells were analyzed for the expression of Foxp3 by flow cytometry. Additionally, we investigated the role of B cells and dendritic cells (DCs) and their stimulatory capacity in the generation of Tregs.


RESULTS
Our results showed that co-culture of naive T cells with the appropriate level of stimulation by APC in the presence of TGF-beta, RA, and IL-2 provided a new powerful approach to generate allogeneic Treg cells. We demonstrated that although B cells and DCs can generate Tregs by themselves, a mixure of both APC improved their capacity to efficiently generate Tregs. Also, we observed that although the addition of IL-2 to the cultures was not crucial to generate Tregs, it was required to optimize their expansion and cell survival.
Moore
C
C
Biology Department, Universidad de Chile, Santiago, Chile.
Sauma
D
D
Reyes
P A
PA
Morales
J
J
Rosemblatt
M
M
Bono
M R
MR
Fierro
J A
JA
D000818:Animals; D000938:Antigen-Presenting Cells / Q000166:cytology / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology*; D015704:CD4 Antigens / Q000276:immunology; D018920:Coculture Techniques; D003713:Dendritic Cells / Q000276:immunology*; D051858:Forkhead Transcription Factors / Q000235:genetics / Q000276:immunology*; D005786:Gene Expression Regulation / Q000187:drug effects / Q000276:immunology; D053645:Interleukin-2 Receptor alpha Subunit / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*; D016212:Transforming Growth Factor beta / Q000494:pharmacology; D014212:Tretinoin / Q000494:pharmacology
D015704:CD4 Antigens; D051858:Forkhead Transcription Factors; C498833:Foxp3 protein, mouse; D053645:Interleukin-2 Receptor alpha Subunit; D016212:Transforming Growth Factor beta; D014212:Tretinoin