Recent data demonstrate the implication of epigenetic alterations in the DNA methylation/hydroxymethylation process in Sjögren’s syndrome (SjS) affecting genes regulated by the interferon (IFN) pathway. This prompts us to test the potential implication of the IFN/JAK/STAT signaling pathway on epigenetic alterations observed in SjS.
Salivary gland epithelial cells (SGEC) were obtained from minor salivary glands, primary long-term culture and/or HSG cell line. DNA level of methylation/demethylation; the expression of the DNA methylating enzymes (DNMTs) and ten-eleven translocation (TETs) methyl cytosine dioxygenase; STAT phosphorylation status, plus ICAM-1 and PD-L1 plasma-membrane levels were determined in the presence of JAK specific inhibitors.
Using a whole methylome approach, an in silico approach to test the relationship between SjS associated single nucleotide polymorphisms (SNP) and DNA methylation quantitative trait loci (meQTLq), and an immunological approach with specific antibodies [3], all these approaches revealed that both IFN type I and type II were able to control DNA methylation in SGEC. Mediated by IFNs, and reactive oxygen species (ROS), the expression of TET3 and in turn global DNA hydroxymethylation were controlled through the induction of STAT3. This process can be reversed by using JAK inhibitors (AG490 and ruxolitinib), leading to the control of DNA methylation/demethylation as well as the control of two plasma-membrane molecules: ICAM-1 and PD-L1 present in IFN activated SGEC.
Treatment with JAK1/2 inhibitors reverses the epigenetic activation profile mediated by interferon pathway, suggesting new ways for establishing innovative treatment regimens in patients with primary SjS.
Primary forms of minimal change disease and focal segmental glomerulosclerosis are rare podocytopathies and clinically characterized by nephrotic syndrome.
Glucocorticoids are the cornerstone of the initial immunosuppressive treatment in these two entities. Especially among adults with minimal change disease or focal segmental glomerulosclerosis, relapses, steroid dependence or resistance are common and necessitate re-initiation of steroids and other immunosuppressants.
Effective steroid-sparing therapies and introduction of less toxic immunosuppressive agents are urgently needed to reduce undesirable side effects, in particular for patients whose disease course is complex. Rituximab, a B cell depleting monoclonal antibody, is increasingly used off-label in these circumstances. While a growing body of evidence supports the use of rituximab in membranous nephropathy, data are less clear for adult patients with minimal change disease and focal segmental glomerulosclerosis.
Hence, critical questions concerning drug-safety, long-term efficacy and the optimal regimen for rituximab-treatment remain unanswered. Evidence in the form of large, multicenter studies and randomized controlled trials are urgently needed to overcome these limitations.
Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by chronic inflammation of multiple organs. Because of the complex and varied clinical manifestations, accurate and timely diagnosis can be challenging. A hallmark of the disease is the presence of autoantibodies specific to self-antigens mainly of nuclear origin. Their detection is of significant value in the classification, diagnosis, prognosis and follow-up of patients. Autoantibodies against Smith (Sm) are very specific for SLE and are part of the classification criteria. In this study, we evaluated the diagnostic accuracy of a new EliA SmDp-S test in patients previously diagnosed with SLE.
The test has been validated against a total of 186 previously obtained serum samples consisting of SLE patients (n=65), disease controls (n=50) and healthy individuals (n=50). Non-SLE patients (n=21) with a false positive EliA SmDp result in the past were additionally included in order to thoroughly investigate the specificity of the new test.
Compared to the current EliA SmDp, the sensitivity of the new EliA SmDp-S is lower. However, the sensitivity can be improved by selecting a lower U/ml cut-off point. Moreover, by testing known EliA SmDp false positive samples, we could demonstrate that the new EliA SmDp-S exhibits substantially improved specificity. Finally, the EliA SmDp-S was proven to have very good intra-assay and inter-assay coefficients of variation, appeared to be insensitive to interference of IgM-class rheumatoid factor and showed clear linearity.
In conclusion, the new SmDp-S test represents an accurate and precise test in detecting anti-Sm antibodies in SLE patients.
Safe and targeted medicines to effectively treat inflammatory bowel diseases (IBDs) are still awaited. Autophagy, a vital self-eating process involved in cellular homeostasis, provides a potential avenue for treating IBDs as several autophagy-related genes are associated with IBD risk. The therapeutic peptide P140 developed in our team is currently evaluated in phase III clinical trials for lupus. It targets key elements of chaperone-mediated autophagy (CMA)1, which is hyperactivated in lupus. The “correcting” effect of P140 on autophagy results in weaker signaling of autoreactive T and B cells, leading to an improvement of physiopathological conditions. Hence, we aim to analyze the therapeutic effects of P140 in animal IBD models.
Susceptible strains of mice have been induced with dextran sulphate sodium (DSS) or trinitrobenzene sulphonic acid (TNBS) colitis and treated with P140 peptide following therapeutic protocols. The clinical course of the colitis has been monitored and animals were sacrificed for pathological and molecular analyses.
Treatment with P140 peptide alleviates the clinical activity markers and repair the intestinal histomorphological damages in DSS and TNBS colitis.
P140 exerts protective effects on the clinical course of chemically induced colitis. The molecular and cellular mechanisms behind this protection are currently investigated, with a special focus on autophagy2.
1. Macri, C. et al. Modulation of deregulated chaperone-mediated autophagy by a phosphopeptide. Autophagy 11, 472–486 (2015).
2. Retnakumar, S. V. & Muller, S. Pharmacological autophagy regulators as therapeutic agents for inflammatory bowel diseases. Trends Mol. Med. 25, 516–537 (2019).
Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease, characterized by inflammation of peripheral joints and bone destruction. Interestingly, around the onset of the disease, autoantibodies against citrullinated proteins cross-react with joint proteins, such as type II collagen (CII). Currently, the medical treatment of established RA is the neutralization of inflammatory mediators such as TNFα. However, these treatments remain problematic, largely because of their non-specific and side-effects. Hence, there is a need for the development of more specific, safer, and more effective therapeutic interventions target the initiating immune mechanisms. The genetic association of RA with certain MHC class II alleles indicate T cells as central players and, consequently, an important target for therapeutic intervention in the disease. We suggest a tolerogenic peptide-based vaccination as a new therapeutic option for the prevention of RA and, possibly, treatment of early/established disease
Humanized mice by knock-in of the ectodomains of humanized alpha chain combined with a humanized beta chain, which leads to the full expression of the human MHC class II molecule.
Collagen-induced arthritis (CIA) and delayed-type hypersensitivity (DTH) models. Flow cytometry. ELISA.
In this sense, we have previously shown that modulation of CII-reactive T cells by vaccination with soluble MHC class II molecules in complex with the glycosylated CII peptide 259-273 efficiently prevents collagen-induced arthritis, as well as also therapeutically cures the disease.
Our current focus is to improve our current vaccine and explore the mechanism of the vaccine induce tolerance, in order to develop an effective vaccine against RA in humans.