Abstract
Purpose:
To determine whether vitreous fluid can promote the generation of Foxp3+ CD4+ T regulatory (Treg) cells in vitro.
Methods:
Vitreous fluid was collected from fresh porcine eyes, sterilized by filtration. Vitreous, used for culture at a final concentration of 25%. Mouse CD4+ T cells purified from pooled splenocytes were stimulated with plate-bound anti-CD3 for 72 h in the presence or absence of vitreous fluid. CD4+ T cells were analyzed for Foxp3 expression using flow cytometry. In some experiments, CD4+ T cells were cultured in the presence of vitreous fluid with or without TGF-β2. For evaluation of T cell activation, culture supernatant was harvested for ELISA assay of interferon (IFN)-γ.
Results:
Vitreous fluid alone did not increase the frequency of Foxp3+ Tregs. Although TGF-β2 induced Foxp3+ Tregs in vitro, the frequency of TGF-β2 induced Foxp3+ Tregs increased significantly in the presence of vitreous fluid. IFN-γ production increased in the presence of vitreous fluid, but decreased significantly in the presence of vitreous fluid plus TGF-β2.
Conclusions:
These findings suggest that vitreous fluid may enhance TGF-β-induced Foxp3+ Treg conversion.