M Yoshida1, T Kezuka, J W Streilein. 1. Schepens Eye Research Institute, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, USA.
Abstract
PURPOSE: To determine whether T cells exposed to cultured iris and ciliary body pigment epithelial (I/CB PE) cells acquire the capacity to modify the activation, differentiation, and effector functions of bystander T cells, and if so, to identify the mechanism. METHODS: T cells from naive BALB/c mice were cultured with I/CB PE cells, x-irradiated, and used as regulators (a) of T-cell activation in vitro and (b) of delayed hypersensitivity expression in vivo. Neutralizing anti-TGF-beta and -IL-10 antibodies were used to abolish regulatory function. T-cell activation was assessed for proliferation by [(3)H]thymidine incorporation and for IL-2, IFN-gamma, IL-4, and IL-10 production by semi-quantitative RT-PCR for mRNA and by supernatant analysis by ELISA. I/CB PE-exposed T cells were evaluated for mRNA content of IFN-gamma, IL-4, TNF-alpha, TGF-beta1, TGF-beta2, and IL-10, and their supernatants were analyzed for content of TGF-beta. RESULTS: T cells exposed to I/CB PE cells inhibited anti-CD3-driven activation of bystander naive T cells in vitro and suppressed the expression of delayed hypersensitivity in vivo. Bystander T cells cocultured with I/CB PE-exposed T cells failed to proliferate and secreted high levels of IL-4 and IL-10 but low amounts of IL-2 and IFN-gamma. Regulation of bystander T-cell activation was mediated via enhanced secretion of TGF-beta by I/CB PE-exposed T cells. CONCLUSIONS: T cells exposed to cultured I/CB PE cells were induced to secrete active and latent TGF-beta, which conferred on the T cells the capacity to inhibit the differentiation as well as the effector function of Th1-type cells.
PURPOSE: To determine whether T cells exposed to cultured iris and ciliary body pigment epithelial (I/CB PE) cells acquire the capacity to modify the activation, differentiation, and effector functions of bystander T cells, and if so, to identify the mechanism. METHODS: T cells from naive BALB/c mice were cultured with I/CB PE cells, x-irradiated, and used as regulators (a) of T-cell activation in vitro and (b) of delayed hypersensitivity expression in vivo. Neutralizing anti-TGF-beta and -IL-10 antibodies were used to abolish regulatory function. T-cell activation was assessed for proliferation by [(3)H]thymidine incorporation and for IL-2, IFN-gamma, IL-4, and IL-10 production by semi-quantitative RT-PCR for mRNA and by supernatant analysis by ELISA. I/CB PE-exposed T cells were evaluated for mRNA content of IFN-gamma, IL-4, TNF-alpha, TGF-beta1, TGF-beta2, and IL-10, and their supernatants were analyzed for content of TGF-beta. RESULTS: T cells exposed to I/CB PE cells inhibited anti-CD3-driven activation of bystander naive T cells in vitro and suppressed the expression of delayed hypersensitivity in vivo. Bystander T cells cocultured with I/CB PE-exposed T cells failed to proliferate and secreted high levels of IL-4 and IL-10 but low amounts of IL-2 and IFN-gamma. Regulation of bystander T-cell activation was mediated via enhanced secretion of TGF-beta by I/CB PE-exposed T cells. CONCLUSIONS: T cells exposed to cultured I/CB PE cells were induced to secrete active and latent TGF-beta, which conferred on the T cells the capacity to inhibit the differentiation as well as the effector function of Th1-type cells.
Authors: Gul Ahmad; Weidong Zhang; Workineh Torben; Chad Haskins; Sue Diggs; Zahid Noor; Loc Le; Afzal A Siddiqui Journal: Parasitol Res Date: 2009-10-07 Impact factor: 2.289