ABSTRACT
PURPOSE: Endogenous toll-like receptor (TLR) 2 is linked to allograft rejection in corneal transplantation. TLR2 also could modulate dendritic cell (DC) phenotype, resulting in T cell polarization. Thus, we investigated the role of endogenous TLR2 on DC development and T cell polarization during corneal rejection. MATERIALS AND METHODS: Corneas of BALB/c mice were transplanted into the eyes of C57BL/6 wild-type (WT) recipients and TLR2-/- (KO) recipients. Graft survival and TLR2 mRNA expression were assessed. At day 14 after transplantation, to study endogenous TLR2 effects on DC development and function, surface expression of MHC class⠡ (MHC⠡), CD86, CD80 and CD40 in ipsilateral cervical draining lymph nodes (DLNs) is measured by flow cytometry, and DC phenotype in corneas is detected by immunofluorescence. The levels of IL-12, IL-10 and IL-4 in corneas were measured by real time-qPCR (RT-qPCR). The ability of DCs to stimulate T cell polarization was assessed by IFN-γ expressions via RT-qPCR and immunohistochemistry. RESULTS: TLR2 mRNA expression in corneas was peaked at day 14 post-transplantation in WT group. KO group improved corneal allograft survival compared to the WT group. In addition, the KO group decreased expression of CD86, CD80 and CD40 on DCs compared to the WT group. There was no difference in MHC⠡ expression in two groups. The CD11c+MHC⠡+CD40high DCs could not be detected in corneas of the KO group. Moreover, the KO group decreased IL-12 (Th1-promoting cytokines) mRNA expression and increasing IL-10 (Treg-promoting cytokines) mRNA expression compared to the WT group. IL-4 (Th2-promoting cytokines) mRNA expression gained no difference between the two groups. The IFN-γ (Th1 cytokines) expression was significantly decreased in the KO group compared to the WT group. CONCLUSIONS: Endogenous TLR2 may contribute to allogeneic corneal rejection via Th1 immunity by activating Th1-promoting DCs and suppressing Treg-promoting DCs.
Subject(s)
Corneal Transplantation , Dendritic Cells/immunology , Disease Models, Animal , Graft Rejection/immunology , T-Lymphocytes, Regulatory/immunology , Th1 Cells/immunology , Toll-Like Receptor 2/physiology , Allografts , Animals , Cytokines/metabolism , Gene Expression , Graft Survival , Interferon-gamma/genetics , Male , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Mice, Knockout , RNA, Messenger/genetics , Real-Time Polymerase Chain ReactionABSTRACT
The prevalence of eye diseases worldwide is dramatically increasing and represents a major concern in underdeveloped and developed regions. Ocular diseases, previously associated with a higher depression risk, also impose a substantial economic burden on affected families, thus early detection and/or accurate treatment in order to avoid and prevent blindness should be emphasized. Ocular neovascularization (NV), the leading cause of blindness in a variety of eye diseases, is a pathologic process characterized by the formation, proliferation and infiltration of anomalous, tiny and leaky fragile blood vessels within the eye. Genetics have been suspected to play an important role in the occurrence of eye diseases, with the detection of a numbers of specific gene mutations. Long non-coding RNA (lncRNAs) are novel class of regulatory molecules previously associated with various biological processes and diseases, however the nature of the relation and pathways by which they might contribute to the development of corneal, choroidal and retinal NV have not yet been completely elucidated. In this review, we focus on the regulation and characteristics of lncRNAs, summarize results from ocular NV-related studies and discuss the implication of lncRNAs in ocular NV development.
ABSTRACT
The levels of neutralizing antibody to a pathogen are an effective indicator to predict efficacy of a vaccine in trial. And yet not all the trial vaccines are in line with the theory. Using dengue virus (DENV) to investigate the viral morphology affecting the predictive value, we evaluated the viral morphology in acute dengue plasma compared to that of Vero cells derived DENV. The virions in plasma were infectious and heterogeneous in shape with a "sunny-side up egg" appearance, viral RNA was enclosed with CD61+ cell-derived membrane interspersed by the viral envelope protein, defined as dengue vesicles. The unique viral features were also observed from ex vivo infected human bone marrow. Dengue vesicles were less efficiently neutralized by convalescent patient serum, compared to virions produced from Vero cells. Our results exhibit a reason why potencies of protective immunity fail in vivo and significantly impact dengue vaccine and drug development.
