The novel Mc4/TSI is a functional indicator of GO activity and severity.

Despite presence of circulating retina-specific T cells in healthy individuals, ocular immune privilege usually averts development of autoimmune uveitis. To study the breakdown of immune privilege and development of disease, we generated transgenic (Tg) mice that express a T cell receptor (TCR) specific for interphotoreceptor retinoid-binding protein (IRBP), which serves as an autoimmune target in uveitis induced by immunization. Three lines of TCR Tg mice, with different levels of expression of the transgenic R161 TCR and different proportions of IRBP-specific CD4+ T cells in their peripheral repertoire, were successfully established. Importantly, two of the lines rapidly developed spontaneous uveitis, reaching 100% incidence by 2 and 3 months of age, respectively, whereas the third appeared “poised” and only developed appreciable disease upon immune perturbation. Susceptibility roughly paralleled expression of the R161 TCR. In all three lines, peripheral CD4+ T cells displayed a naïve phenotype, but proliferated in vitro in response to IRBP and elicited uveitis upon adoptive transfer. In contrast, CD4+ T cells infiltrating uveitic eyes mostly showed an effector/memory phenotype, and included Th1, Th17 as well as T regulatory cells that appeared to have been peripherally converted from conventional CD4+ T cells rather than thymically derived. Thus, R161 mice provide a new and valuable model of spontaneous autoimmune disease that circumvents the limitations of active immunization and adjuvants, and allows to study basic mechanisms involved in maintenance and breakdown of immune homeostasis affecting immunologically privileged sites such as the eye.

We describe here a family of biomimetic iron carriers that display high binding efficiency for ferric ions and favorable permeation properties across erythrocytic membranes. These carriers inhibit in vitro growth of Plasmodium falciparum by scavenging intracellular iron. The chemical features were realized by reproducing the iron-binding cavities of natural iron carriers (siderophores) and by systematic substitutions of their hydrophilic envelopes for more hydrophobic ones. In contrast to natural carriers, which participate in receptor-mediated iron uptake in cells and act as growth promoters, our synthetic carriers were designed to penetrate cellular membranes by diffusion, scavenge intracellular iron, and thereby act as growth inhibitors. Based on these properties we designate the compounds reversed siderophores and refer to the specific analogs of the natural ferrichrome as synthetic ferrichromes. The antimalarial activity of the synthetic ferrichromes correlated with their lipophilicity, and this antimalarial activity was averted when the chelators were applied as iron(lI) complexes. The sites of synthetic ferrichrome action reside in the intraerythrocytic parasite and not in serum or on normal erythrocyte components. The agents were effective against all stages of parasite growth and against a variety of multidrug-resistant strains of P. falkiparum. The most potent agent of this synthetic ferrichrome series, SF1-ileu, was not toxic to mammalian cells in culture and was 15-fold more potent and 20-fold faster acting than desferrioxamine. Taken in toto, these agents constitute a series of promising candidates for future use in malaria chemotherapy.Other types of antimalarial agents are urgently needed to combat the global expansion of malaria. This expansion and the resurgence of drug resistance in various regions of the world have prompted the development of innovative chemotherapeutic strategies (see refs. 1-4 for reviews). Because iron is an essential element for virtually all living species (5), the development of compounds that can exert differential sequestration of essential iron(III) could prove useful for arresting parasite growth, including strains of Plasmodium falciparum of demonstrable drug-resistance nature. Previous attempts to use natural and synthetic iron binders as in vitro and in vivo growth inhibitors of intraerythrocytic parasites scored some success (6-14). However, each class of compounds thus far examined has had some drawbacks. The hydroxamate-based natural siderophores, which are highly specific chelators, are only moderately efficient antimalarials because oftheir poor permeability into infected erythrocytes, their putative site of action (14). Synthetic dithiocarbamates and hydroxyquinolines, on the other hand, proved efficacious, apparently because of a combination of high permeation features and metal complexation; however, their propensity for forming cytotoxic metal complexes might curtail their use in vivo (6-10). Synthetic catecholates, which acted as specific iron sc...

SummaryThyroid-stimulating immunoglobulins (TSI) are a functional biomarker of Graves' disease (GD). To develop a novel TSI bioassay, a cell line (MC4-CHOLuc) was bio-engineered to constitutively express a chimeric TSH receptor (TSHR) and constructed with a cyclic adenosine monophosphate (cAMP)-dependent luciferase reporter gene that enables TSI quantification. Data presented as percentage of specimen-to-reference ratio (SRR%) were obtained from 271 patients with various autoimmune and thyroid diseases and 180 controls. Sensitivity of 96% and specificity of 99% for untreated GD were attained by receiver operating characteristic analysis, area under the curve 0·989, 95% confidence interval 0·969-0·999, P = 0·0001. Precision testing of manufactured reagents of high, medium, low and negative SRR% gave a percentage of coefficient-of-variation of 11·5%, 12·8%, 14·5% and 15·7%, respectively. There was no observed interference by haemoglobin, lipids and bilirubin and no non-specific stimulation by various hormones at and above physiological concentrations. TSI levels from GD patients without (SRR% 406 Ϯ 134, mean Ϯ standard deviation) or under anti-thyroid treatment (173 Ϯ 147) were higher (P < 0·0001) compared with TSI levels of patients with Hashimoto's thyroiditis (51 Ϯ 37), autoimmune diseases without GD (24 Ϯ 10), thyroid nodules (30 Ϯ 26) and controls (35 Ϯ 18). The bioassay showed greater sensitivity when compared with anti-TSHR binding assays. In conclusion, the TSI-Mc4 bioassay measures the functional biomarker accurately in GD with a standardized protocol and could improve substantially the diagnosis of autoimmune diseases involving TSHR autoantibodies.