Characterization of Toxoplasma gondii-specific T cells recovered from vitreous fluid of patients with ocular toxoplasmosis
PURPOSE: The mechanisms involved in reactivations of latent ocular Toxoplasma gondii (Tg) infections in immunocompetent patients are poorly understood. In view of the possible role of T cells in the immunopathogenesis of the disease, ocular infiltrating T cells obtained from patients with recurrent ocular toxoplasmosis were characterized phenotypically and functionally. METHODS: Ocular infiltrating T cells were recovered from vitreous fluid (VF) samples of 10 patients with active recurrent ocular toxoplasmosis. Two patients with uveitis of other origins were included as control subjects. T-cell lines (TCLs) were generated by mitogenic stimulation and tested for reactivity to Tg and human retinal protein extracts. The TCLs of three patients were cloned by limiting dilution. Tg-reactive T-cell clones (TCCs) were characterized with respect to their phenotype, T-cell receptor variable (TCR V)-beta gene usage, HLA restriction, and cytokine secretion profile. RESULTS: Reactivity to Tg could be detected only in the TCLs of patients with ocular toxoplasmosis. None of the TCLs showed reactivity to human retinal antigens. All tested intraocular Tg-specific TCCs (n = 23) were CD3+CD4+ and displayed differential TCR Vbeta usage. Twenty-one TCCs were HLA-DR restricted and two TCCs were restricted by HLA-DP. The majority of the intraocular Tg-specific TCCs showed a bias toward a T-helper (Th)0-Th2 cytokine profile. CONCLUSIONS: The data indicate that T cells specific for the triggering microorganism infiltrate the eye of patients with recurrent ocular toxoplasmosis. The functional characteristics of the VF-derived Tg-specific T cells and their presence at the site of inflammation suggest their involvement in the local inflammatory response of ocular toxoplasmosis.
|Keywords||Adult, Aged, Animals, Antigens, CD3/analysis, Antigens, CD4/analysis, Cytokines/metabolism, Female, HLA Antigens/analysis, Humans, Male, Middle aged, Phenotype, Receptors, Antigen, T-Cell, alpha-beta/analysis, Research Support, Non-U.S. Gov't, T-Lymphocytes/*immunology/physiology, Toxoplasma/*immunology, Toxoplasmosis, Ocular/*immunology/pathology/physiopathology, Uveitis/immunology/pathology/physiopathology, Vitreous Body/*immunology/pathology|
Feron, E.J., Klaren, V.N., Wierenga, E.A., Kijlstra, A., Prof. Dr, & Verjans, G.M.G.M.. (2001). Characterization of Toxoplasma gondii-specific T cells recovered from vitreous fluid of patients with ocular toxoplasmosis. Investigative Ophthalmology & Visual Science. Retrieved from http://hdl.handle.net/1765/9798