AAV2-Mediated Subretinal Gene Transfer of hIFN-α Attenuates Experimental Autoimmune Uveoretinitis in Mice

BACKGROUND: Recent reports show that gene therapy may provide a long-term, safe and effective intervention for human diseases. In this study, we investigated the effectiveness of adeno-associated virus 2 (AAV2) based human interferon-alpha (hIFN-α) gene therapy in experimental autoimmune uveoretinitis (EAU), a classic model for human uveitis. METHODOLOGY/PRINCIPAL FINDINGS: An AAV2 vector harboring the hIFN-α gene (AAV2.hIFN-α) was subretinally injected into B10RIII mice at two doses (1.5×10(6) vg, 1.5×10(8) vg). AAV2 vector encoding green fluorescent protein (AAV2.GFP) was used as a control (5×10(8) vg). The expression of hIFN-α in homogenized eyes and serum was detected by ELISA three weeks after injection. The biodistribution of vector DNA in the injected eyes, contralateral eyes and distant organs was determined by PCR. EAU was induced by immunization with IRBP(161-180) three weeks following vector injections, and evaluated clinically and pathologically. IRBP-specific proliferation and IL-17 expression of lymphocytes from the spleen and lymph nodes were assayed to test the influence of the subretinal delivery of AAV2.hIFN-α on the systemic immune response. hIFN-α was effectively expressed in the eyes from three weeks to three months following subretinal injection of AAV2.hIFN-α vector. DNA of AAV2.GFP was observed only in the injected eyes, but not in the distant organs or contralateral eyes. Subretinal injection of both doses significantly attenuated EAU activity clinically and histologically. For the lower dose, there was no difference concerning lymphocyte proliferation and IL-17 production among the AAV2.hIFN-α, AAV2.GFP and PBS injected mice. However, the higher dose of AAV2.hIFN-α significantly suppressed lymphocyte proliferation and IL-17 production. CONCLUSIONS/SIGNIFICANCE: Subretinal delivery of AAV2.hIFN-α lead to an effective expression within the eye for at least three months and significantly attenuated EAU activity. AAV2.hIFN-α was shown to inhibit the systemic IRBP-specific immune response

Supervised Classification of Power Lines from Airborne LiDAR Data in Urban Areas

Automatic extraction of power lines using airborne LiDAR (Light Detection and Ranging) data has been one of the most important topics for electric power management. However, this is very challenging over complex urban areas, where power lines are in close proximity to buildings and trees. In this paper, we presented a new, semi-automated and versatile framework that consists of four steps: (i) power line candidate point filtering, (ii) local neighborhood selection, (iii) spatial structural feature extraction, and (iv) SVM classification. We introduced the power line corridor direction for candidate point filtering and multi-scale slant cylindrical neighborhood for spatial structural features extraction. In a detailed evaluation involving seven scales and four types for local neighborhood selection, 26 structural features, and two datasets, we demonstrated that the use of multi-scale slant cylindrical neighborhood for individual 3D points significantly improved the power line classification. The experiments indicated that precision, recall and quality rate of power line classification is more than 98%, 98% and 97%, respectively. Additionally, we showed that our approach can reduce the whole processing time while achieving high accuracy

Higher Expression of Toll-like Receptors 2, 3, 4, and 8 in Ocular Behcet's Disease

PURPOSE. To investigate the role of Toll-like receptors (TLRs) 2, 3, 4, and 8 in the pathogenesis of Behcet's disease (BD). METHODS. Sixteen patients with active ocular BD and 16 healthy volunteers were included in this study. Total RNA was isolated from PBMCs to determine mRNA levels of TLRs, including TLR2, TLR3, TLR4, and TLR8. Cell surface receptor activity of these TLRs was investigated by FACS analysis. Monocytes and naive T cells from patients and controls were cultured with or without TLR ligands, such as LPS, PGN, R848, or PolyI:C. Culture supernatants were collected and IL-17, IL-1 beta, and IL-23 were analyzed by ELISA. RESULTS. A markedly higher expression at the mRNA and protein level of TLR2, TLR3, TLR4, and TLR8 was observed in active BD patients as compared with controls. Significantly higher levels of IL-1 beta and IL-23 were detected in the supernatants of monocytes stimulated with LPS or PGN. A significantly higher level of IL-17 was observed in the supernatants of naive T cells and monocytes stimulated with LPS or PGN in BD patients as compared with controls. Upon stimulation with R848 or PolyI: C, the levels of IL-17 in the supernatants of naive T cells and monocytes and IL-23 levels in the supernatants of monocytes were not different between BD patients and controls. CONCLUSIONS. A higher expression of TLRs may be involved in the pathogenesis of BD

Decreased Expression of the Aryl Hydrocarbon Receptor in Ocular Behcet's Disease

Recent studies show that the aryl hydrocarbon receptor (AhR) is involved in immune responses. AhR is activated following interaction with its ligands, such as 6-formylindolo[3,2-b]carbazole (FICZ) and 2-(1′H-indole-3′-carbonyl)-thiazole-4-carboxylic acid methyl ester (ITE). In this study, we investigated the role of AhR activation by its endogenous ligands in the pathogenesis of ocular Behcet’s disease (BD). The expression of AhR was significantly decreased in active BD patients as compared to inactive BD patients and normal controls. Both FICZ and ITE inhibited Th1 and Th17 polarization and induced the expression of IL-22 by PBMCs and by CD4+T cells in active BD patients and normal controls. Stimulation of purified CD4+T cells with FICZ or ITE caused a decreased expression of RORC, IL-17, IL-23R, and CCR6 and an increased phosphorylation of STAT3 and STAT5. The present study suggests that a decreased AhR expression is associated with disease activity in BD patients. The activation of AhR by either FICZ or ITE was able to inhibit Th1 and Th17 cell polarization. Further studies are needed to investigate whether modulation of AhR might be used in the treatment of BD

QuickBird image-based estimation of tree stand density using local maxima filtering method: A case study in a Beijing forest.

The stand density of trees affects stand growth and is useful for estimating other forests structure parameters. We studied tree stand density in Jiufeng National Forest Park in Beijing. The number of spectral local maxima points (NSLMP) calculated within each sample plot was extracted by the spectral maximum filtering method using QuickBird imagery. Regression analysis of NSLMP and the true stand density collected by ground measurements using differential GPS and the total station were used to estimate stand density of the study area. We used NSLMP as an independent variable and the actual stand density as the dependent variable to develop separate statistical models for all stands in the coniferous forest and broadleaf forest. By testing the different combination of Normalized Difference Vegetation Index (NDVI) thresholds and window sizes, the optimal selection was identified. The combination of a 3 × 3 window size and NDVI ≥ 0.3 threshold in coniferous forest produced the best result using near-infrared band (coniferous forest R2 = 0.79, RMSE = 12.60). The best combination for broadleaf forest was a 3 × 3 window size and NDVI ≥ 0.1 with R2 = 0.44, RMSE = 9.02 using near-infrared band. The combination of window size and NDVI threshold for all unclassified forest was 3 × 3 window size and NDVI ≥ 0.3 with R2 = 0.70, RMSE = 11.20 using near-infrared band. A stand density planning map was constructed using the best models applied for different forest types. Different forest types require the use of different combination strategies to best extract the stand density by using the local maximum (LM). The proposed method uses a combination of high spatial resolution imagery and sampling plots strategy to estimate stand density

Inhibition of Proinflammatory Cytokine by IL-25 in Vogt-Koyanagi-Harada Syndrome

Purpose: Vogt-Koyanagi-Harada (VKH) syndrome is a multisystem disorder presumed to be mediated by an autoimmune response. Recent studies have shown that interleukin (IL) 25 was involved in the T-cell immune response. This study analyzed the expression and potential role of IL-25 in the pathogenesis of VKH syndrome. Methods: The IL-25 serum levels were determined by enzyme-linked immunosorbent assay (ELISA). The IL-1 beta, IL-6, and TNF-alpha level in supernatants of PBMCs cultured with LPS in the absence or presence of recombinant(r) IL-25 was detected by ELISA. Results: A significantly decreased serum IL-25 level was found in VKH patients. In vitro experiments showed that rIL-25 was able to significantly inhibit the production of IL-1 beta, IL-6, and TNF-alpha by PBMCs from active VKH patients. Conclusions: IL-25 may be involved in the development of VKH syndrome, possibly by inhibiting the expression of proinflammatory cytokines

Decreased interleukin 27 expression is associated with active uveitis in Behçet’s disease

INSTRUCTION: Interleukin 27 (IL-27) is an important regulator of the proinflammatory T-cell response. In this study, we investigated its role in the pathogenesis of Behçet’s disease (BD). METHODS: IL-27 mRNA in peripheral blood mononuclear cells (PBMCs) was examined by performing RT-PCRs. Cytokine levels in sera or supernatants of PBMCs, naïve CD4(+) T cells, dendritic cells (DCs) and DC/T cells were determined by enzyme-linked immunosorbent assay. We used RNA interference in naïve CD4(+) T cells to study the role of interferon regulatory factor 8 (IRF8) in the inhibitory effect of IL-27 on Th17 cell differentiation. Flow cytometry was used to evaluate the frequency of IL-17- and interferon γ–producing T cells. RESULTS: The expression of IL-27p28 mRNA by PBMCs and IL-27 in the sera and supernatants of cultured PBMCs were markedly decreased in patients with active BD. A higher frequency of IL-17-producing CD4(+) T (Th17) cells and increased IL-17 production under Th17 polarizing conditions were observed in patients with active BD. IL-27 significantly inhibited Th17 cell differentiation. Downregulation of IRF8 by RNA interference abrogated the suppressive effect of IL-27 on Th17 differentiation. IL-27 inhibited the production of IL-1β, IL-6 and IL-23, but promoted IL-10 production, by DCs. IL-27-treated DCs inhibited both the Th1 and Th17 cell responses. CONCLUSIONS: The results of the present study suggest that a decreased IL-27 expression is associated with disease activity in BD patients. Low IL-27 expression may result in a higher Th1 and Th17 cell response and thereby promote the autoinflammatory reaction observed in BD. Manipulation of IL-27 may offer a new treatment modality for this disease