TGF-β1 along with other platelet contents augments Treg cells to suppress anti-FVIII immune responses in hemophilia A mice.
Platelets are a rich source of many cytokines and chemokines including transforming growth factor β 1 (TGF-β1). TGF-β1 is required to convert conventional CD4+T (Tconv) cells into induced regulatory T (iTreg) cells that express the transcription factor Foxp3. Whether platelet contents will affect Treg cell properties has not been explored. In this study, we show that unfractionated platelet lysates (pltLys) containing TGF-β1 efficiently induced Foxp3 expression in Tconv cells. The common Treg cell surface phenotype and in vitro suppressive activity of unfractionated pltLys-iTreg cells were similar to those of iTreg cells generated using purified TGF-β1 (purTGFβ-iTreg) cells. However, there were substantial differences in gene expression between pltLys-iTreg and purTGFβ-iTreg cells, especially in granzyme B, interferon γ, and interleukin-2 (a 30.99-, 29.18-, and 17.94-fold difference, respectively) as determined by gene microarray analysis. In line with these gene signatures, we found that pltLys-iTreg cells improved cell recovery after transfer and immune suppressive function compared with purTGFβ-iTreg cells in factor VIII (FVIII)-deficient (F8null, hemophilia A model) mice after recombinant human FVIII (rhF8) infusion. Acute antibody-mediated platelet destruction in F8nullmice followed by rhF8 infusion increased the number of Treg cells and suppressed the antibody response to rhF8. Consistent with these data, ex vivo proliferation of F8-specific Treg cells from platelet-depleted animals increased when restimulated with rhF8. Together, our data suggest that pltLys-iTreg cells may have advantages in emerging clinical applications and that platelet contents impact the properties of iTreg cells induced by TGF-β1.
Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI; Children's Research Institute, Children's Hospital of Wisconsin, Milwaukee, WI; Midwest Athletes Against Childhood Cancer Fund Research Center, Milwaukee, WI.
Dipica
D
Haribhai
Blood Research Institute, BloodCenter of Wisconsin, Milwaukee, WI; Fujian Institute of Hematology, Fujian Medical University Union Hospital, Fuzhou, China.
Xiaofeng
X
Luo
Blood Research Institute, BloodCenter of Wisconsin, Milwaukee, WI.
Juan
J
Chen
Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI; Children's Research Institute, Children's Hospital of Wisconsin, Milwaukee, WI.
Shuang
S
Jia
Blood Research Institute, BloodCenter of Wisconsin, Milwaukee, WI.
Linzheng
L
Shi
Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI; Children's Research Institute, Children's Hospital of Wisconsin, Milwaukee, WI; Midwest Athletes Against Childhood Cancer Fund Research Center, Milwaukee, WI; Blood Research Institute, BloodCenter of Wisconsin, Milwaukee, WI.
Jocelyn A
JA
Schroeder
Blood Research Institute, BloodCenter of Wisconsin, Milwaukee, WI.
Hartmut
H
Weiler
Blood Research Institute, BloodCenter of Wisconsin, Milwaukee, WI.
Richard H
RH
Aster
Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI; Children's Research Institute, Children's Hospital of Wisconsin, Milwaukee, WI.
Martin J
MJ
Hessner
Fujian Institute of Hematology, Fujian Medical University Union Hospital, Fuzhou, China.
Jianda
J
Hu
Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI; Children's Research Institute, Children's Hospital of Wisconsin, Milwaukee, WI; Midwest Athletes Against Childhood Cancer Fund Research Center, Milwaukee, WI.
Calvin B
CB
Williams
Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI; Children's Research Institute, Children's Hospital of Wisconsin, Milwaukee, WI; Midwest Athletes Against Childhood Cancer Fund Research Center, Milwaukee, WI; Blood Research Institute, BloodCenter of Wisconsin, Milwaukee, WI.
Qizhen
Q
Shi