Farida Fortune

Genome-wide association study identifies variants in the MHC class I, IL10, and IL23R-IL12RB2 regions associated with Behcet's disease

Behçets disease is a genetically complex disease of unknown etiology characterized by recurrent inflammatory attacks affecting the orogenital mucosa, eyes and skin. We performed a genome-wide association study with 311,459 SNPs in 1,215 individuals with Behçets disease (cases) and 1,278 healthy controls from Turkey. We confirmed the known association of Behçets disease with HLA-B*51 and identified a second, independent association within the MHC Class I region. We also identified an association at IL10 (rs1518111, P = 1.88 × 10−8). Using a meta-analysis with an additional five cohorts from Turkey, the Middle East, Europe and Asia, comprising a total of 2,430 cases and 2,660 controls, we identified associations at IL10 (rs1518111, P = 3.54 × 10−18, odds ratio = 1.45, 95% CI 1.34–1.58) and the IL23R-IL12RB2 locus (rs924080, P = 6.69 × 10−9, OR = 1.28, 95% CI 1.18–1.39). The disease-associated IL10 variant (the rs1518111 A allele) was associated with diminished mRNA expression and low protein production.

Role of γδ T cells in pathogenesis and diagnosis of Behçet's disease

Abstract Summary Background Behcets disease (BD) is a multisystem disorder of unknown pathogenesis. The diagnosis is based on a set of international clinical criteria. Previous investigations have suggested that immunological crossreactivity between peptides within streptococcal heat-shock proteins and human peptides might be involved in the pathogenesis of BD. We tested four peptides from mycobacterial heat-shock proteins to see if they specifically stimulated γδ T cells from BD patients. We then investigated this response to see whether it could be used as a laboratory test to diagnose BD. Methods We used a T-cell proliferative test to assay responses to four mycobacterial 65 kDa heat-shock-protein peptides and to four homologous peptides derived from the sequence of the human 60 kDa heat-shock protein. Findings We elicited significant γδ T-cell responses to the mycobacterial peptides in 25 (76%) of 33 patients with BD, compared with 2 (3·6%) of 55 controls with recurrent oral ulcers, systemic disease, or no disorders. The proportion of BD patients who had false-negative results decreased if the test was done during clinical manifestation of disease activity. There was a correlation between disease activity and T-cell responses. Four homologous peptides from human 60 kDa heat-shock protein also specifically stimulated T cells from patients with BD but with lower stimulation indices. Interpretation Activation of peripheral-blood mononuclear cells with the four heat-shock-protein peptides elicited significant T-cell proliferative responses by the γδ subset of T cells, which may regulate αβ T cells. Because these peptides have a high specificity for BD, this assay can be used as a laboratory diagnostic test for BD.

FOXM1 Upregulation Is an Early Event in Human Squamous Cell Carcinoma and it Is Enhanced by Nicotine during Malignant Transformation

Background Cancer associated with smoking and drinking remains a serious health problem worldwide. The survival of patients is very poor due to the lack of effective early biomarkers. FOXM1 overexpression is linked to the majority of human cancers but its mechanism remains unclear in head and neck squamous cell carcinoma (HNSCC). Methodology/Principal Findings FOXM1 mRNA and protein expressions were investigated in four independent cohorts (total 75 patients) consisting of normal, premalignant and HNSCC tissues and cells using quantitative PCR (qPCR), expression microarray, immunohistochemistry and immunocytochemistry. Effect of putative oral carcinogens on FOXM1 transcriptional activity was dose-dependently assayed and confirmed using a FOXM1-specific luciferase reporter system, qPCR, immunoblotting and short-hairpin RNA interference. Genome-wide single nucleotide polymorphism (SNP) array was used to ‘trace’ the genomic instability signature pattern in 8 clonal lines of FOXM1-induced malignant human oral keratinocytes. Furthermore, acute FOXM1 upregulation in primary oral keratinocytes directly induced genomic instability. We have shown for the first time that overexpression of FOXM1 precedes HNSCC malignancy. Screening putative carcinogens in human oral keratinocytes surprisingly showed that nicotine, which is not perceived to be a human carcinogen, directly induced FOXM1 mRNA, protein stabilisation and transcriptional activity at concentrations relevant to tobacco chewers. Importantly, nicotine also augmented FOXM1-induced transformation of human oral keratinocytes. A centrosomal protein CEP55 and a DNA helicase/putative stem cell marker HELLS, both located within a consensus loci (10q23), were found to be novel targets of FOXM1 and their expression correlated tightly with HNSCC progression. Conclusions/Significance This study cautions the potential co-carcinogenic effect of nicotine in tobacco replacement therapies. We hypothesise that aberrant upregulation of FOXM1 may be inducing genomic instability through a program of malignant transformation involving the activation of CEP55 and HELLS which may facilitate aberrant mitosis and epigenetic modifications. Our finding that FOXM1 is upregulated early during oral cancer progression renders FOXM1 an attractive diagnostic biomarker for early cancer detection and its candidate mechanistic targets, CEP55 and HELLS, as indicators of malignant conversion and progression.

γδ T cells in Behçet's disease (BD) and recurrent aphthous stomatitis (RAS)

The immunopathogenesis of BD is believed to be T cell‐mediated. The objective of this study was to characterize the activation stage and cytokine profile of peripheral blood lymphocytes (PBL), with particular emphasis on γδ T cells. Venous blood was collected from 20 patients with BD, and for comparison, from 11 patients with RAS and from 15 healthy controls. Both the expression of activation markers (CD25, CD29, CD40 ligand, CD69 and HLA‐DR) on freshly isolated PBL and T cell subsets, and the expression of intracellular cytokines (IL‐4, IL‐10, interferon‐gamma (IFN‐γ) and tumour necrosis factor‐alpha (TNF‐α)) on mitogen‐stimulated PBL and T cell subsets were analysed by double immunofluorescent staining and flow cytometry. Significantly decreased proportion of αβ T cells and increased proportion of γδ T cells, CD56+ cells and CD8+γδ T cells were found in BD patients compared with healthy controls. This was also seen to a lesser extent in patients with RAS. Furthermore, in BD a significantly increased proportion of the γδ T cell population expressed CD69 and high levels of CD29 and were induced to produce IFN‐γ and TNF‐α compared with healthy controls. In contrast, an increased percentage of γδ T cells from RAS patients was induced to produce IFN‐γ, but not TNF‐α. These results indicate that in BD, activated γδ T cells, capable of producing IFN‐γ and TNF‐α, are present in peripheral blood, suggesting that γδ T cells are dynamic and may be regulating immunopathogenic events.

Cardiac hypertrophy, hypertrophic cardiomyopathy, and hyperparathyroidism--an association.

Left ventricular hypertrophy (symmetric, asymmetric, or hypertrophic cardiomyopathy) is an almost invariable accompaniment of primary hyperparathyroidism. Five of 18 patients with hypertrophic cardiomyopathy had raised serum concentrations of parathyroid hormone with normal serum calcium concentrations. Left ventricular hypertrophy did not occur in any of the six patients with hypercalcaemia alone. These relations suggest that parathyroid hormone rather than a rise in the extracellular calcium concentration is associated with a spectrum of left ventricular hypertrophy. All patients with increased circulating parathyroid hormone concentrations should have echocardiographic examination of the left ventricle. Conversely, parathyroid hormone concentrations should be measured in all patients with left ventricular hypertrophy from an unknown cause, especially those with hypertrophic cardiomyopathy.

Expression of cytokines, chemokines, and chemokine receptors in oral ulcers of patients with Behcet's disease (BD) and recurrent aphthous stomatitis is Th1‐associated, although Th2‐association is also observed in patients with BD

Objective: Although the pathogenesis of Behcets disease (BD) is unknown, immune dysfunction appears to be involved. To improve understanding of the role of T cells and cytokines in BD, the current study analysed the localization and extent of expression of T cell subsets, cytokines, chemokines, and chemokine receptors in oral ulcers from BD patients and for comparison in oral ulcers from patients with recurrent aphthous stomatitis (RAS), as well as in healthy oral mucosa. Methods: Biopsies from oral ulcers of 25 BD patients and 19 RAS patients and oral mucosa from six healthy volunteers were immunoperoxidase stained. Results: Both CD4‐ and CD8‐positive T cells were present in the oral ulcers of BD and RAS patients. The T helper (Th)1 cytokines interleukin (IL)‐12, interferon (IFN)‐γ, and tumour necrosis factor (TNF)α and the Th1‐associated chemokine receptors CCR5 and CXCR3 were increased in both patient groups as compared to normal controls, indicating the involvement of a Th1 immune response in the immunopathology of both BD and RAS. However, the Th2 cytokine IL‐4 was only observed in oral ulcers of BD patients but not in RAS patients. Conclusion: This is the first study that shows the presence of pro‐inflammatory cytokines, as well as Th1‐associated chemokine receptors, in the oral ulcers of BD patients, as well as RAS patients, at a protein level. However, the expression of the Th2 cytokine IL‐4 within the oral lesions of only BD patients is suggestive of a more complex antigenic stimuli in BD patients compared with RAS patients.

A systematic review of medical interventions for oral submucous fibrosis and future research opportunities.

Oral Diseases (2011) 17 (Suppl. 1), 42-57 Oral submucous fibrosis (OSF) is a chronic, insidious disease caused by areca nut use, and is associated with both significant morbidity (including pain and reduced oral opening) and an increased risk for malignancy. This systematic review explored and updated the current medical (i.e., non-surgical) interventions available for the management of OSF. Of the 27 published medical interventions, there were four randomized controlled trials. The overall quality of these randomized controlled studies was assessed using the GRADE approach and significant limitations that challenged the conclusions were found. However, this review was valuable in terms of identifying opportunities to provide recommendations for future research, in terms of the populations to research, the types of interventions needed, the types of outcomes to be measured, the study designs needed, and the infrastructure required to conduct studies. The next step is to initiate a pathway for a low-cost research plan leading to the development of a brief protocol for future clinical trials in this field, with an emphasis on conducting studies in regions of the world where OSF is prevalent.

Orofacial granulomatosis: review on aetiology and pathogenesis

Orofacial granulomatosis (OFG) is considered as an uncommon disease and nomenclature of the disease was subjected to debate for a long time. Although various aetiological agents such as food substances, food additives, dental materials and various microbiological agents have been implicated in the disease process its precise pathogenesis is yet to be elucidated. Delayed type of hypersensitivity reaction appears to play a significant role, although the exact antigen inducing the immunological reaction varies in individual patients. However, evidence for the role of genetic predisposition to the disease is sparse. The underlying immunological mechanism appears to show some similarities between OFG and Crohns disease, emphasizing the need for more comparative studies of the two entities. Therefore, we propose the term idiopathic OFG as a better term for those cases restricted to oral region without any identifiable known granulomatous disease and the diagnosis should not be changed until the patient develops systemic manifestations of a specific granulomatous condition. This review attempts to discuss the role of different aetiological agents and certain aspects of pathogenesis of OFG.

Betel-derived alkaloid up-regulates keratinocyte alphavbeta6 integrin expression and promotes oral submucous fibrosis

Oral submucous fibrosis (OSF) is a premalignant, fibrosing disorder of the mouth, pharynx, and oesophagus, with a malignant transformation rate of 7–13%. OSF is strongly associated with areca (betel) nut chewing and worldwide, over 5 million people are affected. As αvβ6 integrin is capable of promoting both tissue fibrosis and carcinoma invasion, we examined its expression in fibroepithelial hyperplasia and OSF. αvβ6 was markedly up‐regulated in OSF, with high expression detected in 22 of 41 cases (p < 0.001). We investigated the functional role of αvβ6 using oral keratinocyte‐derived cells genetically modified to express high αvβ6 (VB6), and also NTERT‐immortalized oral keratinocytes, which express low αvβ6 (OKF6/TERT‐1). VB6 cells showed significant αvβ6‐dependent activation of TGF‐β1, which induced transdifferentiation of oral fibroblasts into myofibroblasts and resulted in up‐regulation of genes associated with tissue fibrosis. These experimental in vitro findings were confirmed using human clinical samples, where we showed that the stroma of OSF contained myofibroblasts and that TGF‐β1‐dependent Smad signalling was detectable both in keratinocytes and in myofibroblasts. We also found that arecoline, the major alkaloid of areca nuts, up‐regulated keratinocyte αvβ6 expression. This was modulated through the M4 muscarinic acetylcholine receptor and was suppressed by the M4 antagonist, tropicamide. Arecoline‐dependent αvβ6 up‐regulation promoted keratinocyte migration and induced invasion, raising the possibility that this mechanism may support malignant transformation. Over 80% of OSF‐related oral cancers examined had moderate/high αvβ6 expression. These data suggest that the pathogenesis of OSF may be epithelial‐driven and involve arecoline‐dependent up‐regulation of αvβ6 integrin. Copyright

Recognition of B-Cell Epitopes of the 65 kDa HSP in Behçet's Disease

B‐cell epitopes of the mycobacterial 65 kDa heat shock protein (HSP) were mapped in sera from patients with Behçets Disease (BD). A series of 47 overlapping synthetic peptides (15ers) derived from the sequence of the Mycobacterium tuberculosis 65 kDa HSP was used in ELISA. Significant increases in IgA and IgG antibody levels were observed with peptides 111–125, 154–172 and 311–326 in sera from BD, compared with those from controls. Homologous peptides derived from the sequence of the human mitochondrial 60 kDa HSP were then examined. Peptides 136–150 and 336–351 showed comparable results to the homologous mycobacterial peptides 111–125 and 311–326, respectively. The B‐cell epitopes defined in this investigation overlap with the T‐cell epitopes the authors have previously reported in BD. Inhibition studies are consistent with the view that antibodies to each of the three B‐cell epitope peptides represent a small proportion of the total B‐cell epitope repertoire elicited by the 65 or 60 kD HSP. Sequential antibody studies suggest that IgA and IgG antibody titres to one or all three peptides tested may increase during exacerbations of ocular disease. The functional role of these antibodies needs to be determined, but the peptides may be involved in the immunopathogenesis of BD as they can induce experimental uveitis in Lewis rats, which is a principal manifestation of BD.