Interaction of copolymer-1-activated T cells and microglia in retinal ganglion cell protection

Abstract

Background: The interaction of copolymer-1-activated T cells and microglia on retinal ganglion cells survival in vitro was explored. Methods: Copolymer-1-specific T cells were made by repeated copolymer-1 stimulation of T cells, microglia were isolated from the retinas of newborn rats, and then, they were co-cultured (the experimental group) for 48h. Retinal ganglion cells were collected from the retinas of adult rats, purified, and then, the supernatants from different groups were added. After 72h, terminal-deoxynucleotidyl transferase-mediated d-UTP nick end labelling analysis was used to observe retinal ganglion cell apoptosis, and reverse transcription polymerase chain reaction was used to test messenger RNA expression of Caspase-3 and Caspase-8. The levels of cytokines, including insulin-like growth factor-1, brain-derived neurotrophic factor, tumour necrosis factor-α and interleukin-10, in the supernatants were examined by enzyme-linked immunosorbent assay to explore the possible mechanisms undergoing. Results: After 72h, the mean retinal ganglion cell apoptosis rate in the experimental group was the lowest (25.36%) among the groups. The messenger RNA expression of Caspase-3 and Caspase-8 in this group was significantly lower than that of the control groups (both P<0.05). The secretion of interlekin-10 and brain-derived neurotrophic factor, insulin-like growth factor-1 and tumour necrosis factor-α in the supernatant of the experimental group were higher than that of the control groups (both P<0.05) after co-culture. Conclusions: The interaction of copolymer-1-specific T cells with microglia could reduce retinal ganglion cell apoptosis. The related immune mechanisms were complicated. Upregulation of brain-derived neurotrophic factor and insulin-like growth factor-1, and the balance of some pro-inflammatory and anti-inflammatory cytokines may be involved in this protective autoimmunity. © 2013 Royal Australian and New Zealand College of Ophthalmologists.