Trypan blue induces apoptosis in human retinal pigment epithelial cells.

Purpose: To examine whether trypan blue dye induces apoptosis in human retinal pigment epithelium cells.

Design: Laboratory investigation.

Methods: Pure cultures of human retinal pigment epithelium cells were isolated.

Indocyanine green induces apoptosis in human retinal pigment epithelial cells.

Purpose: To examine whether indocyanine green (ICG) dye induces apoptosis in human retinal pigment epithelial (RPE) cells.

Design: Laboratory investigation.

Methods: Pure cultures of human RPE cells were isolated.

The effect of type I and II interferons on human fetal retinal pigment epithelium-induced apoptosis in Jurkat T cells.

Purpose: To examine the regulatory effects of interferon (IFN)-alpha, IFN-gamma, transforming growth factor (TGF)-beta, and tumor necrosis factor (TNF)-alpha on human fetal retinal pigment epithelial (HFRPE) cell-induced apoptosis of human Jurkat T (Jkt) cells.

Methods: Pure cultures of HFRPE cells were isolated. The cells were precultured with medium alone or with addition of IFN-alpha, IFN-gamma, TNF-alpha, or TGF-beta for 72 hours.

Human fetal retinal pigment epithelium induces apoptosis in human T-cell line Jurkat which is independent from its expression of TRAIL.

Purpose: To evaluate whether human fetal retinal pigment epithelial (HFRPE) cells express TRAIL (tumor necrosis factor related apoptosis inducing ligand). The role of TRAIL in HFRPE induced apoptosis was evaluated.

Methods: Pure cultures of HFRPE cells were isolated.

Cytokine modulation of costimulatory molecules on human fetal retinal pigment epithelial cells.

Purpose: Experiments were performed to evaluate the effect of various pro- and anti-inflammatory cytokines on the human fetal retinal pigment epithelium's (HFRPE) expression of major histocompatibility complex (MHC) and costimulatory molecules.

Methods: Pure cultures of HFRPE cells were isolated. HFRPE cells were incubated in the presence of Interferon-gamma (IFN-gamma), IFN-beta, Tumor Necrosis Factor-alpha (TNF-alpha), Interleukin-1beta (IL-1beta), Tumor Growth Factor-beta (TGF-beta), and a combination of IFN-gamma and TGF-beta (pre-incubation and simultaneously incubated).

IL-12 decreases activation-induced cell death in human naive Th cells costimulated by intercellular adhesion molecule-1. I. IL-12 alters caspase processing and inhibits enzyme function.

Th cells can receive costimulatory signals through the LFA-1/ICAM-1 accessory pathway that are sufficient to induce early Th cell proliferation, but not subsequent cell expansion and maintenance of cell viability. To investigate the regulatory role for IL-12 in ICAM-1-mediated costimulation, human naive Th cells were stimulated with coimmobilized anti-CD3 mAb and ICAM-1 Ig in the presence or absence of IL-12. The ICAM-1-mediated costimulatory signals in this model resulted in early Th cell proliferation followed by cell death that was partially mediated by Fas and involved loss of mitochondrial membrane potential, processing of procaspase-9 and -3, and activation of caspase-3.

Human fetal retinal pigment epithelium-induced cell cycle arrest, loss of mitochondrial membrane potential and apoptosis.

Purpose: To investigate the mechanism of action of the soluble immune suppressive product secreted by human fetal retinal pigment epithelial (HFRPE) cells in a model system using the human T-cell line Jurkat (Jkt).

Methods: Pure HFRPE cells were isolated and cultured. The supernatants of both nonactivated and IFN-gamma-activated HFRPE cells were isolated.

A model for xenogenic immune response.

Purpose: To develop a model for analyzing the immune response after xenogenic human fetal retinal pigment epithelium (HFRPE) transplantation.

Materials And Methods: Pure sheets of HFRPE cells were isolated and attached to poly (DL-lactide-co-glycolide) polymer films and HFRPE spheroids were formed. The spheroids were transplanted into the subretinal space of New Zealand albino rabbits and were observed for 5 months.

Human fetal retinal pigment epithelium suppresses the activation of CD4(+) and CD8(+) T-cells.

Background: The suppressive effect of human fetal retinal pigment epithelium (HFRPE) on the activation of human CD4(+) and CD8(+) T-cells was evaluated in vitro.

Methods: Pure populations of CD4(+) and CD8(+) T-cells were isolated from human peripheral blood-derived buffy coats by negative immunomagnetic selection. The purity of the cells was examined by flow cytometry using anti-CD3-FITC, anti-CD4-FITC, anti-CD8-PE, and anti-CD20-PE mAbs.

Human fetal retinal pigment epithelial cells induce apoptosis in allogenic T-cells in a Fas ligand and PGE2 independent pathway.

Purpose: To evaluate the inhibitory effect of human fetal retinal pigment epithelium (HFRPE) on the activation of human T-cells.

Methods: Pure cultures of HFRPE cells were incubated with purified human T-cells in three different activation assays: 1) allogenic peripheral blood mononuclear cells; 2) OKT3 coated beads in the presence of accessory cells; and 3) stimulation with phorbol ester and phytohemagglutinin.

Results: HFRPE cells suppressed the activation of T-cells in all three assays.

Cryoprecipitate: An autologous substrate for human fetal retinal pigment epithelium.

Purpose: To harvest thin membranes from cryoprecipitates isolated from human blood donors and utilize them as substrates for the adhesion of human fetal retinal pigment epithelial (HFRPE) cells.

Methods: Frozen human cryoprecipitates from anonymous blood donors were obtained from the blood bank. Thin cryo-membranes were harvested by their mixture with riboflavin-5-phosphate (R5P) and overnight exposure to ultra-violet light.

Human fetal retinal pigment epithelial cells induce apoptosis in the T-cell line Jurkat.

Purpose: To investigate the mechanism(s) involved in human fetal retinal pigment epithelium (HFRPE)-mediated T-cell death.

Methods: Pure HFRPE cells were isolated and cultured. Normal and interferon (IFN)-gamma-activated HFRPE from early and late in vitro passages were incubated with cells from the human T-cell leukemia line Jurkat (Jkt).

Biodegradable polymer film as a source for formation of human fetal retinal pigment epithelium spheroids.

Purpose: To evaluate the attachment of human fetal rctinal pigment epithelial (HFRPE) cells to a biodegradable polymer film with subsequent formation of spheroids in vitro.

Methods: Ten biodegradable polymer films with different compositions were examined for their physical properties and ease of manipulation under a dissecting microscope. The film with the most suitable handling characteristics was chosen, and a purely isolated sheet of HFRPE cells was attached to it.

Growth of human fetal retinal pigment epithelium as microspheres.

Background: The aim was to develop a three-dimensional cell culture system for human fetal retinal pigment epithelial (HFRPE) cells for in vitro cellular studies and for possible application in subretinal transplantation.

Methods: Pieces of freshly isolated HFRPE monolayer tissue were grown on crosslinked fibrinogen (CLF) films. The growth pattern and morphologic characteristics of the implanted tissue were studied using phase-contrast microscopy, photography, and light and electron microscopy.

A new method of culturing and transferring iris pigment epithelium.

Purpose: To optimize a culture technique and transfer iris pigment epithelial (IPE) cells for cellular studies in vitro.

Methods: Porcine iris tissues were obtained, and IPE cells were isolated and cultured at high densities by plating them in the form of drops. Spherically shaped structures containing a high concentration of cells were formed after 7 to 10 days of culture.

Iris pigment epithelial cells of long evans rats demonstrate phagocytic activity.

The phagocytic activities of iris pigment epithelial (IPE) cells and retinal pigment epithelial (RPE) cells of Long Evans rats towards latex beads and rod outer segments (ROS) were compared in vitro. IPE and RPE cells of Long Evans rats were isolated and pure cultures obtained. The cultures were incubated with latex beads, fixed, and analysed computer morphometrically, IPE and RPE cell cultures were also incubated with isolated ROS and examined using transmission electron microscopy.