Mouse Sertoli cells sustain de novo generation of regulatory T cells by triggering the notch pathway through soluble JAGGED1.
FOXP3(+) regulatory T cells (Tregs) are central to the maintenance of immunological homeostasis and tolerance. It has long been known that Sertoli cells are endowed with immune suppressive properties; however, the underlying mechanisms as well as the effective nature and role of soluble factors secreted by Sertoli cells have not been fully elucidated as yet. We hypothesized that conditioned medium from primary mouse Sertoli cells (SCCM) may be able and sufficient to induce Tregs. By culturing CD4(+)CD25(-)EGFP(-) T splenocytes purified from FOXP3-EGFP knock-in mice in SCCM, here we show, by flow cytometry and suppression assay, the conversion of peripheral CD4(+)FOXP3(-) T cells into functional CD4(+)FOXP3(+) Tregs. We also demonstrate that the Notch/Jagged1 axis is involved in regulating the de novo generation of Tregs although this process is transforming growth factor-beta1 (TGF-B) dependent. In particular, we identified by Western blot analysis a soluble form of JAGGED1 (JAG1) in SCCM that significantly influences the induction of Tregs, as demonstrated by performing the conversion assay in presence of a JAG1-specific neutralizing antibody. In addition, we show that SCCM modulates the Notch pathway in converted Tregs by triggering the recruitment of the Notch-specific transcription factor CSL/RBP-Jk to the Foxp3 promoter and by inducing the Notch target gene Hey1, as shown by chromatin immunoprecipitation assay and by real time-RT-PCR experiments, respectively. Overall, these results contribute to a better understanding of the molecular mechanisms involved in Sertoli cell-mediated immune tolerance and provide a novel approach to generate ex vivo functional Tregs for therapeutic purpose.
Department of Molecular Medicine, Sapienza University, Rome, Italy.
Antonio Francesco
AF
Campese
Paola
P
Grazioli
Paola
P
de Cesaris
Anna
A
Riccioli
Diana
D
Bellavia
Maria
M
Pelullo
Fabrizio
F
Padula
Claudia
C
Noce
Sofia
S
Verkhovskaia
Antonio
A
Filippini
Giovanni
G
Latella
Isabella
I
Screpanti
Elio
E
Ziparo
Donatella
D
Starace
D000818:Animals; D015153:Blotting, Western; D015704:CD4 Antigens / Q000096:biosynthesis / Q000235:genetics; D002135:Calcium-Binding Proteins / Q000235:genetics / Q000502:physiology*; D018797:Cell Cycle Proteins / Q000235:genetics; D047369:Chromatin Immunoprecipitation; D005434:Flow Cytometry; D051858:Forkhead Transcription Factors / Q000502:physiology; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics / Q000502:physiology*; D000072100:Jagged-1 Protein; D008297:Male; D008565:Membrane Proteins / Q000235:genetics / Q000502:physiology*; D051379:Mice; D061251:Primary Cell Culture; D060888:Real-Time Polymerase Chain Reaction; D051880:Receptors, Notch / Q000235:genetics / Q000502:physiology*; D000072099:Serrate-Jagged Proteins; D012708:Sertoli Cells / Q000502:physiology*; D013489:Suppression, Genetic; D050378:T-Lymphocytes, Regulatory / Q000502:physiology*; D014162:Transfection; D016212:Transforming Growth Factor beta / Q000502:physiology
D015704:CD4 Antigens; D002135:Calcium-Binding Proteins; D018797:Cell Cycle Proteins; D051858:Forkhead Transcription Factors; C498833:Foxp3 protein, mouse; C120420:Hey1 protein, mouse; D036341:Intercellular Signaling Peptides and Proteins; C000606274:Jag1 protein, mouse; D000072100:Jagged-1 Protein; D008565:Membrane Proteins; D051880:Receptors, Notch; D000072099:Serrate-Jagged Proteins; D016212:Transforming Growth Factor beta
JAGGED1; Sertoli cells; Treg cells; immunology; testis immune privilege