Thrombopoietin Secretion by Human Ovarian Cancer Cells

The thrombopoietin (TPO) gene expression in human ovary and cancer cells from patients with ovarian carcinomatosis, as well as several cancer cell lines including MDA-MB231 (breast cancer), K562 and HL60 (Leukemic cells), OVCAR-3NIH and SKOV-3 (ovarian cancer), was performed using RT PCR, real-time PCR, and gene sequencing. Human liver tissues are used as controls. The presence of TPO in the cells and its regulation by activated protein C were explored by flow cytometry. TPO content of cell extract as well as plasma of a patient with ovarian cancer was evaluated by ELISA. The functionality of TPO was performed in coculture on the basis of the viability of a TPO-dependent cell line (Ba/F3), MTT assay, and Annexin-V labeling. As in liver, ovarian tissues and all cancer cells lines except the MDA-MB231 express the three TPO-1 (full length TPO), TPO-2 (12 bp deletion), and TPO-3 (116 pb deletion) variants. Primary ovarian cancer cells as well as cancer cell lines produce TPO. The thrombopoietin production by OVCAR-3 increased when cells are stimulated by aPC. OVCAR-3 cell’s supernatant can replace exogenous TPO and inhibited TPO-dependent cell line (Ba/F3) apoptosis. The thrombopoietin produced by tumor may have a direct effect on thrombocytosis/thrombosis occurrence in patients with ovarian cancer

Étude du rôle physiopathologique de la transglutaminase tissulaire, des anticorps anti-transglutaminase tissulaire et de la gliadine dans la maladie coeliaque (un nouveau support en catalyse)

Les principaux objectifs de notre travail ont consisté d'abord à évaluer l'apport des anticorps anti-tTG (AtTG) dans le diagnostic et dans le dépistage de la maladie coeliaque puis à essayer d'améliorer notre compréhension sur le rôle et l'interaction de ces trois éléments clefs du développement de la MC : la tTG, la gliadine et les AtTG. Dans un premier temps, nous avons montré que la recherche des AtTG doit être réalisée systématiquement chez les enfants qui présentent des signes cliniques isolés évocateurs d'une MC et chez les enfants atteints d'un diabète de type 1 et ce, afin de mettre en route un régime sans gluten le plus précocement possible. Parallèlement nous avons démontré également que la technique ELISA a une meilleure sensibilité et une meilleure spécificité que la technique dot blot pour la recherche AtTG. La sensibilité des AAE est meilleure que celle des AtTG, AAR et AAG. Ensuite dans une étude réalisée sur des biopsies provenant de patients cœliaques présentant différents stades d'atrophie villositaire, a permis de montrer que la localisation de la tTG était modifiée au cours de la MC. L'enzyme présente une expression préférentielle au niveau de la membrane basale et de la lamina propria au cours de la MC alors que sa localisation est plutôt restreinte aux entérocytes dans la muqueuse normale. Son activité de transamidation n'est cependant pas modifiée. Nous avons également démontré que la tTG pouvait générer des peptides toxiques de la gliadine parallèlement à son rôle de production de peptides immunogènes. Ces deux types de peptides agiraient en synergie entraînant le développement des lésions caractéristiques de la MC. Concernant le rôle des AtTG, nous n'avons pas montré d'effet direct sur les cellules; néanmoins nous avons montré que ces anticorps entraînent une diminution de l'activité enzymatique de la tTGLYON1-BU.Sciences (692662101) / SudocSudocFranceF

Altered patterns of epigenetic changes in systemic lupus erythematosus and auto-antibody production: is there a link?

International audienceThe prominent feature of immunological defects in systemic lupus erythematosus (SLE) is the production of autoantibodies (auto-Abs) to nuclear antigens including DNA, histones and RNP. In addition, there is growing evidence that epigenetic changes play a key role in the pathogenesis of SLE. Autoreactive CD4(+) T cells and B cells in patients with SLE have evidence of altered patterns of DNA methylation as well as post-translational modifications of histones and ribonucleoproteins (RNP). A key question that has emerged from these two characteristic features of SLE is whether the two processes are linked. New data provide support for such a link. For example, there is evidence that hypomethylated DNA is immunogenic, that anti-histone auto-Abs in patients with SLE bind epigenetic-sensitive hot spots and that epigenetically-modified RNP-derived peptides can modulate lupus disease. All in all, the available evidence indicates that a better understanding of dysregulation in epigenetics in SLE may offer opportunities to develop new biomarkers and novel therapeutic strategies

Frequency of antithyroid antibodies in patients with primary biliary cholangitis

OBJECTIVE: Primary biliary cholangitis (PBC) is an autoimmune disease of liver that may be associated with other conditions, including autoimmune thyroid diseases. We aimed to investigate the frequency of anti-thyroperoxidase antibodies (TPO-Ab), antithyroglobulin antibodies (TG-Ab), and anti-thyrotropin receptor antibodies (TSHR-Ab) in Tunisian patients with PBC.METHODS: Sera of 80 patients with PBC were collected over a 9-year period. A total of 189 healthy blood donors (HBD) were included in the control group. Measurements of TPO-Ab and TG-Ab were performed using indirect enzyme-linked immunosorbent assay (ELISA). Competitive ELISA was used to assess TSHR-Ab. RESULTS: Antithyroid antibodies (ATA) were significantly more frequent in PBC patients than in the control group (13.7% vs 1.6%; P &lt; 10-3). Out of 11 patients with ATA, 10 (90.9%) were female. Nine patients and 2 HBD had TPO-Ab (11.2% vs 1%; P &lt; 10-3). TG-Ab were more frequent in patients than in healthy subjects but the difference was not statistically significant (6.2% vs 1.6%; P = .1). TPO-Ab and TG-Ab were present together in 3 patients (3.7%). TSHR-Ab were absent in patients and controls. CONCLUSION: This study shows that PBC is associated with a high frequency of ATA but not TG-Ab or TSHR-Ab.</p

Frequency of antithyroid antibodies in patients with primary biliary cholangitis

OBJECTIVE: Primary biliary cholangitis (PBC) is an autoimmune disease of liver that may be associated with other conditions, including autoimmune thyroid diseases. We aimed to investigate the frequency of anti-thyroperoxidase antibodies (TPO-Ab), antithyroglobulin antibodies (TG-Ab), and anti-thyrotropin receptor antibodies (TSHR-Ab) in Tunisian patients with PBC.METHODS: Sera of 80 patients with PBC were collected over a 9-year period. A total of 189 healthy blood donors (HBD) were included in the control group. Measurements of TPO-Ab and TG-Ab were performed using indirect enzyme-linked immunosorbent assay (ELISA). Competitive ELISA was used to assess TSHR-Ab. RESULTS: Antithyroid antibodies (ATA) were significantly more frequent in PBC patients than in the control group (13.7% vs 1.6%; P &lt; 10-3). Out of 11 patients with ATA, 10 (90.9%) were female. Nine patients and 2 HBD had TPO-Ab (11.2% vs 1%; P &lt; 10-3). TG-Ab were more frequent in patients than in healthy subjects but the difference was not statistically significant (6.2% vs 1.6%; P = .1). TPO-Ab and TG-Ab were present together in 3 patients (3.7%). TSHR-Ab were absent in patients and controls. CONCLUSION: This study shows that PBC is associated with a high frequency of ATA but not TG-Ab or TSHR-Ab.</p

Epigenetic dysregulation in salivary glands from patients with primary Sjögren's syndrome may be ascribed to infiltrating B cells.

International audienceSjögren's syndrome (SS) is an autoimmune exocrinopathy characterized by an epithelium injury with dense lymphocytic infiltrates, mainly composed of activated T and B cells. Present at the interface of genetic and environmental risk factors, DNA methylation is suspected to play a key role in SS. To clarify this point, global DNA methylation was tested within salivary gland epithelial cells (SGEC), peripheral T cells and B cells from SS patients. Global DNA methylation was reduced in SGEC from SS patients, while no difference was observed in T and B cells. SGEC demethylation in SS patients was associated with a 7-fold decrease in DNA methyl transferase (DNMT) 1 and a 2-fold increase in Gadd45-alpha expression. The other DNA methylation/demethylation partners, tested by real time PCR (DNMT3a/b, PCNA, UHRF1, MBD2, and MBD4), were not different. Interestingly, SGEC demethylation may be attributed in part to the infiltrating B cells as suspected in patients treated with anti-CD20 antibodies to deplete B cells. Such hypothesis was confirmed using co-culture experiments with human salivary gland cells and B cells. Furthermore, B cell-mediated DNA demethylation could be ascribed to an alteration of the PKC delta/ERK/DNMT1 pathway. As a consequence, part of the SGEC dysfunction in SS may be linked to epigenetic modifications, thus opening new therapeutic perspectives in SS

Serological markers of rheumatoid arthritis in patients with primary biliary cholangitis and the vice versa: A Tunisian study

Background: Primary biliary cholangitis (PBC) is an autoimmune disease of the liver characterized by destructive lymphocytic cholangitis and anti-mitochondrial antibodies (AMA). Anti-gp210 and anti-Sp100, are used for the diagnosis of PBC in AMA-negative PBC patients. Patients with PBC have a propensity to have an extrahepatic manifestation which is especially autoimmune. Objective: We aimed to determine the frequency of serological markers of rheumatoid arthritis (RA) (CCP-Ab or RF) in PBC patients and to do the vice versa. Methods: Our PBC study included 70 patients with PBC and 80 healthy blood donors (HBD) and our RA study included 75 patients with RA and 75 HBD. Anti-cyclic citrullinated peptide antibodies (CCP-Ab) and rheumatoid factor (RF) were performed by indirect ELISA. AMA, anti-Sp100 and anti-gp210 were determined by indirect immunofluorescence. Results: RA autoantibodies (CCP-Ab or RF) were more frequent in PBC patients than in HBD (65.7% vs. 8.7% p 〈1 0 −6). CCP-Ab were significantly more frequent in patients than in controls (15.7% vs. 2.5%; p = 0.004). Nine patients had both CCP-Ab and RF vs. none of controls (12.8% vs. 0%; p = 0.001). RF were detected in 45 patients with PBC and in 5 HBD (64.3% vs. 6.2%; p 〈1 0 −6). In PBC patients, RF were more frequent than CCP-Ab (64.3% vs. 15.7%; p 〈1 0 −6). RF-IgG were present in 18.5% of patients; RF-immunoglobulin (Ig) A in 34.3% and RF-IgM in 54.3%. These frequencies were significantly higher than those found in control group (1.2% for RF-IgG (p 〈1 0 −3); 0% for RF-IgA (p 〈1 0 −6); and 6.2% for RF-IgM (p 〈1 0 −6)). In our PBC patients, RF-IgA were more frequent than RF-IgG (34.3% vs. 18.5%; p = 0.03) and than CCP-Ab (34.3% vs. 15.7%; p = 0.01). Six patients had only RF-IgA versus none of the control group (8.6% vs. 0%; p = 0.01). AMA, anti-Sp100 and anti-gp 210 were absent in all RA patients. Conclusions: Serological markers of RA were more frequent in PBC patients than in HBD and the vice versa was not true

Human regulatory B cells control the TFH cell response

International audienc