No abstract

The results suggest that murine HSK improves after AMT through reduced local T-helper cell immune responses by inducing apoptosis in T lymphocytes, independently of passive apoptosis or activation-induced cell death. AM also reduces local T-helper cytokine and chemokine levels but does not result in immune deviation. Immunologic memory against HSV-1 is not affected by AMT, and long-term protection or tolerance is not induced.

This review gives an overview on molecules that play a critical role in the pathogenetic process of uveitis, as has been observed in patients or the respective animal models, and summarizes the current experience with biologicals for the treatment of uveitis refractive to conventional immunosuppressives.

Necrotizing herpetic stromal keratitis (HSK) in mice rapidly improved after amniotic membrane transplantation (AMT). In this study we determined the fate of polymorphonuclear neutrophils (PMN) after AMT. AMT or tarsorrhaphy (T) was performed in BALB/c mice with ulcerative HSK. After 2 days, corneas were studied histologically and by transmission electron microscopy (TEM). CD11b, Gr-1, and TUNEL-positive cells were identified. Macrophages were depleted by subconjunctival injection of dichloromethylene-diphosphonate-liposomes (Cl 2 MDP-LIP) before AMT. Corneas were studied for interleukin (IL)-1α, IL-2, interferon (IFN)-γ, CXCL1, CXCL2, and tumor necrosis factor (TNF)-α production by ELISA. PMN-enriched cell preparations cocultured with amniotic membrane (AM) or with AM and such recombinant (r) cytokines as rIL-1α, rIL-2, and rTNF-α or supernatants from activated lymphocytes were investigated by flow cytometry (Annexin-V/7-AAD and TUNEL), and a dimethylthiazolyl-diphenyltetrazoliumbromide (MTT)-viability assay. Corneas in the AMT mice had less inflammation, fewer PMN-like cells and fewer CD11b+, and Gr-1+ cells (P < 0.01), but a higher ratio of apoptotic to viable PMN-resembling cells (P < 0.01) than the T mice. Phagocytic removal of apoptotic PMN-like cells by macrophages was evident in the AMT group. After Cl 2 MDP-LIP treatment, the corneas had more cell debris and apoptotic cells with PMN-like morphology. The concentrations of IL-1 α, IL-2, CXCL1, and TNF-α were reduced in corneas of the AMT group as compared to that of the T group, while the concentration of CXCL2 was increased. Apoptosis of PMN-resembling cells was detected following cocultivation with AM, even when proinflammatory cytokines were present. Resolution of corneal inflammation in mice with necrotizing HSK after AMT is associated with increased apoptosis of PMN-like cells, reduction of pro-inflammatory cytokines, an increase of CXCL2, and increased removal of apoptotic PMN-like cells by macrophages.

Based on these results it can be concluded that the action mechanism of AM is associated with modulation of classically activated macrophages into alternatively activated macrophages or macrophage cell death, probably by engaging lipid metabolism and activating the PPAR-γ pathway, consequently curtailing effector T cell functions. Apoptotic cells induced in the environment with AM support the presence and survival of such macrophages.

No abstract

It can be concluded that TNF-α participates mainly in the immunopathology in the induction phase of EAU. The mechanism of action underlying EAU improvement may be different for local and systemic etanercept treatment.

RPE cultivation with UV-POS might serve as a model to investigate the accumulation of lipofuscin-like structures. The enhanced cytokine secretion due to UV-POS with HCS may account for an increased susceptibility for lipofuscin-loaded cells to complement, inducing a proinflammatory environment as observed in AMD.