Aim: To investigate T-bet mRNA and protein expression on peripheral blood monanuclear cells (PBMC) in patients with Behcet's disease with active uveitis. Methods: Blood samples were taken from 24 patients with Behcet's disease who had active uveitis and 16 healthy individuals. PBMC were subjected to analysis of T-bet mRNA nd protein expression using semiquatitative reverse tran scriptase-polymerase chain reaction (RT-PCR) and western blot, respectively. The products from PCR were sequenced. In order to determine the influence of activation on T-bet expression, the phytohaemagglutinin (PHA) stimulated PBMC from each sample were also evaluated for expression of T-bet mRNA and protein. Results: A significantly increased T-bet mRNA accumulation was detected in the samples from patients with active Behcet's disease compared with that in controls. A 62 kDa band was detectable in patients with active Behcet's disease, but not in controls. No difference was found between patients with Behcet's disease who had active uveitis and normal controls concerning the expression of either T-bet mRNA or its protein after stimulation with PHA for 72 hours. Conclusion: Behcet's disease is associated with an upregulation of T-bet expression, which supports a role for the Thl subset of T cells in the pathogenesis of this disease.

shares many similarities with the human eye and is considered as a suitable species to investigate the pathogenesis of human ocular disease. The aim of this study was to investigate the presence of immunocompetent cells in the uveal tract of the normal pig. Methods. Iris and choroid wholemounts and cryostat sections were obtained from normal pig eyes. Single and double immunohistochemistry was performed by using anti-porcine leukocyte (CD45), anti-porcine macrophage (CD163, CD14), anti-porcine MHC class II (MCA1335), anti-human MHC class II (MCA379G), anti-porcine B lymphocyte (IgM), anti-porcine T lymphocyte (CD6) and anti-porcine granulocyte (MCA1219) monoclonal antibodies. Results. A rich network of dendritiform CD163 positive tissue macrophages was observed in normal pig iris and choroid wholemounts (368+84/mm2, 402+97/mm2, respectively). Approximately 50% of the CD163 positive tissue macrophages in the iris coexpressed MHC class II. Double immunostaining revealed that a small population of the MHC class II positive cells, did not express macrophage markers, and probably represent classical DCs. B lymphocytes and granulocytes were not detected in iris and choroid whole mounts. An occasional T cell could be observed per high power field in iris wholemounts but not in the choroid. Conclusions. The present study reveals that the normal piguveal tract contains a rich network of tissue macrophages and MHC class II positive dendritiform cells. At least three populations could be distinguished: MHC class II positive and negative tissue macrophages and MHC class II+ dendritiform cells lacking tissue macrophage markers.

ononuclear cells were isolated by centrifugation with Ficoll-Paque and cultured in RPMI 164o with or without phytohemagglutinin (PHA) for 9h at 37℃ in an atmosphere with 5% CO2. The obtained cells were incubated with anti-Fas antibody for 8h at 37℃ in an atmosphere with 5% CO2. The cells were stained with annexin V/propidium iodide and finally subjected to flow cytometry. Results: A significantly lower percentage of apoptotic lymphocytes after PHA stimulation was noted in Behcet's disease (19.7±4.1%) and VKH syn drome (2o.4±6.9%) than in controls (26.1±7.3%). The percentage of apoptotic lymphocytes without PHA stimulation also tended to be lower in the patients with BehCet's disease (12.6%) and with VKH syndrome (12.8%) than in controls (14.6%), although the difference was not significant. Conclusion: Lymphocytes in patients with either Behcet's disease or VKH syndrome are relatively resistant to apoptosis mediated by anti-Fas antibody. These apoptosis-resistant, or longlived, lymphocytes may be involved in the chronic and recurrent intraocular inflammation seen in these patients.