Spontaneous Ocular Autoimmunity in Mice Expressing a Transgenic T Cell Receptor Specific to Retina: A Tool to Dissect Mechanisms of Uveitis.

The "classical" EAU model induced by immunization of mice with the retinal protein IRBP or its peptides has been very useful to study basic mechanisms of ocular inflammation, but is inadequate for some types of studies due to the need for active immunization in the context of strong bacterial adjuvants. We generated transgenic (Tg) mice on the B10.RIII background that express a T cell receptor (TCR) specific for IRBP161-180. Three strains of TCR Tg mice were established. Spontaneous uveitis developed in two of the three strains by 2-3 months of age. Susceptibility correlated with a higher copy number of the transgenic TCR and a higher proportion of TCR Tg T cells in the peripheral repertoire. Even in mice with uveitis, peripheral IRBP-specific CD4(+) T cells displayed mostly a naïve phenotype. In contrast, T cells infiltrating uveitic eyes mostly showed an effector/memory phenotype, and included Th1, Th17 as well as T regulatory cells. These mice thus provide a new and distinct model of uveitis from the "classical" EAU, and may represent some types of uveitis more faithfully. Importantly, this new transgenic model of uveitis can serve as a template for therapeutic manipulations, and as a source of naïve retina-specific T cells for a variety of basic and pre-clinical studies. Several examples of such studies will be discussed.

p21 gene polymorphisms in systemic lupus erythematosus.

OBJECTIVE: Cyclin-dependent kinase inhibitor 1A (p21) is a negative regulator in the cell cycle. Development of sex-linked lupus-like syndrome in p21-/- mice and reduced p21 gene expression in patients with systemic lupus erythematosus (SLE) compared with those in healthy controls suggested that p21 is a susceptibility gene of SLE. We investigated the same by a case-control association study. METHODS: Six single nucleotide polymorphisms, p21US G/A, p21DS C/A, p21-1022 G/A, p21C31 C/A, p21In2 G/C and p21UTR T/C, were genotyped in 516 SLE patients and 693 healthy controls. Association of genotypes and alleles with disease, disease phenotypes, haplotypes construction, linkage disequilibrium analysis and p21 mRNA expression were performed. RESULTS: We found a significant association of p21US A allele (OR = 0.23, 95% CI: 0.14-0.38, P < 0.001) and p21-1022 A allele (OR = 1.95, 95% CI: 1.37-2.78, P < 0.001) with SLE. We identified significant differences in the frequencies of haplotypes ht1-ACACCC, which contains p21US A allele, and ht2-GCACCC, which contains p21-1022 A allele, between SLE patients and controls (P < 0.0001). Besides, the p21US GA was associated with SLE patients suffering from arthritis (P = 0.003). We also observed differential p21 mRNA expressions among different genotypes of p21US and p21-1022 which were statistically significant. CONCLUSION: Our results suggested that the p21US A allele and p21-1022 A allele were both associated with the development of SLE, and the p21US A allele was associated with arthritis in SLE patients.

Clinical experience in coronary stenting with the Vivant Z Stent.

This single centre study was designed to demonstrate feasibility, safety and efficacy of the Vivant Z stent (PFM AG, Cologne, Germany). Patients with de novo lesion were recruited. Coronary angioplasty was performed with either direct stenting or after balloon predilatation. Repeated angiogram was performed 6 months later or earlier if clinically indicated. Between January to June 2003, a total of 50 patients were recruited (mean age 55.8 +/- 9 years). A total of 52 lesions were stented successfully. Mean reference diameter was 2.77 mm (+/-0.59 SD, range 2.05-4.39 mm) with mean target lesion stenosis of 65.5% (+/-11.6 SD, range 50.1-93.3%). Forty-six lesions (88.5%) were American College of Cardiologist/American Heart Association class B/C types. Direct stenting was performed in 18 (34.6%) lesions. Mean stent diameter was 3.18 mm (+/-0.41 SD, range 2.5-4 mm), and mean stent length was 14.86 mm (+/-2.72 SD, range 9-18 mm). The procedure was complicated in only one case which involved the loss of side branch with no clinical sequelae. All treated lesions achieved Thrombolysis In Myocardial Infarction 3 flow. Mean residual diameter stenosis was 12.2% (+/-7.55 SD, range 0-22.6%) with acute gain of 1.72 mm (+/-0.50 SD, range 0.5-2.8). At 6 months, there was no major adverse cardiovascular event. Repeated angiography after 6 months showed a restenosis rate of 17% (defined as >50% diameter restenosis). Mean late loss was 0.96 mm (+/-0.48 SD) with loss index of 0.61 (+/-0.38 SD). The restenosis rate of those lesions less than 3.0 mm in diameter was 22.2% compared with 6.25% in those lesions more than 3.0 mm in diameter. The Vivant Z stent was shown to be safe and efficacious with low restenosis rate in de novo coronary artery lesion.

Association of interferon gamma and interleukin 10 genes with tuberculosis in Hong Kong Chinese.

Interferon gamma (IFN-gamma) and interleukin 10 (IL-10) are believed to play opposing roles in host immunity against mycobacterial infection. IFN-gamma activates macrophages, while IL-10 downregulates the expression of T helper type 1 cytokines, MHC class II antigens and costimulatory molecules on macrophages. Associations of IFN-gamma -179 (G/T), +874 (A/T), +875 miscrosatellite CA repeats and +4766 (C/T), and IL-10 -1082 (A/G), -819 (C/T) and -592 (C/A) with tuberculosis (TB) were investigated in 385 HIV-negative patients and 451 controls in a Hong Kong Chinese population. The frequency of a low IFN-gamma-producing +874 A/A genotype was significantly over-represented in the patient group (P<0.001, OR=3.79, 95% CI=1.93-7.45). We identified 10 alleles in the IFN-gamma CA repeats and observed a significant difference in allele frequency distribution between patients and controls (P<0.001). By grouping alleles into 12 and non-12 CA repeats, the non-12/non-12 genotype yielded a similar significant result (P<0.001, OR=4.56, 95% CI=2.21-9.43) as observed in +874 A/A genotype. Weak associations of the IL-10 GCC/- genotype (P=0.04) and the low IFN-gamma-producing A/A genotype (P=0.06) with TB relapse/extrapulmonary cases were found. This study suggests the possible role of interferon gamma in TB susceptibility.

Association of interleukin-10 promoter polymorphisms with systemic lupus erythematosus.

Several lines of evidence suggest interleukin-10 gene (IL-10) is a candidate gene in susceptibility to systemic lupus erythematosus (SLE). We investigated the association of IL-10 promoter single-nucleotide polymorphisms (SNPs) (-3575T/A, -2849G/A, -2763C/A, -1082A/G, -819T/C and -592A/C) and microsatellites (IL10.R, IL10.G) with SLE in 554 Hong Kong Chinese patients and 708 ethnically matched controls. Six haplotypes (hts) were identified from the SNPs. The genotype distribution of the ht1 (T-C-A-T-A), which is associated with low IL-10 production, was different in patients and controls (P=0.009). The homozygous genotype of non-ht1 was significantly increased in patients (P=0.009, odds ratio (OR)=1.80, 95% CI: 1.15-2.82). The frequency of IL10.G4 of IL10.G was also significantly increased in patients (P=0.017, OR=2.53, 95% CI: 1.18-5.40). We found that the homozygous non-ht1 combined with short allele (CA repeat number < or =21) of IL10.G has a dose-dependent effect on SLE susceptibility: non-ht1/non-ht1 with homozygous short allele showed a higher OR (OR=4.11, 95% CI: 1.27-13.2, P=0.018) of association with SLE than the genotype of non-ht1/non-ht1 with heterozygous short/long allele (OR=2.98, 95% CI: 1.26-7.07, P=0.013) and homozygous long allele (OR=1.05, 95% CI: 0.62-1.78, P=0.848). The frequency of non-ht1 was significantly increased in patients with serositis (P<0.0001, OR=2.42, 95% CI: 1.55-3.80). In conclusion, the high expression promoter genotype is associated with SLE in Chinese.