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Imbalances in the gut microbiome are suspected contributors to the pathogenesis of Systemic Lupus Erythematosus, and our studies and others have documented that patients with active Lupus nephritis have expansions of the obligate anaerobe, Blautia (Ruminococcus) gnavus (RG). To investigate whether the RG strains in Lupus patients have in vivo pathogenic properties in a gnotobiotic system, we colonized C57BL/6 mice with individual RG strains from healthy adults or those from Lupus patients. These strains were similar in their capacity for murine intestinal colonization of antibiotic-preconditioned specific-pathogen-free, as well as of germ-free adults and of their neonatally colonized litters. Lupus-derived RG strains induced high levels of intestinal permeability that was significantly greater in female than male mice, whereas the RG species-type strain (ATCC29149/VPI C7-1) from a healthy donor had little or no effects. These Lupus RG strain-induced functional alterations were associated with RG translocation to mesenteric lymph nodes, and raised serum levels of zonulin, a regulator of tight junction formation between cells that form the gut barrier. Notably, the level of Lupus RG-induced intestinal permeability was significantly correlated with serum IgG anti RG cell-wall lipoglycan antibodies, and with anti-native DNA autoantibodies that are a biomarker for SLE. Strikingly, gut permeability was completely reversed by oral treatment with larazotide acetate, an octapeptide that is a specific molecular antagonist of zonulin. Taken together, these studies document a pathway by which RG strains from Lupus patients contribute to a leaky gut and features of autoimmunity implicated in the pathogenesis of flares of clinical Lupus disease.

Women with scleroderma (SSc) maintain significantly higher quantities of persisting fetal microchimerism (FMc) from complete or incomplete pregnancies in their peripheral blood compared to healthy women. The non-classical class-I human leukocyte antigen (HLA) molecule HLA-G plays a pivotal role for the implantation and maintenance of pregnancy and has often been investigated in offspring from women with pregnancy complications. However data show that maternal HLA-G polymorphisms as well as maternal soluble HLA-G (sHLA-G) expression could influence pregnancy outcome. Here, we aimed to investigate the underlying role of maternal sHLA-G expression and HLA-G polymorphisms on the persistence of FMc. We measured sHLA-G levels by enzyme linked immunosorbent assay in plasma samples from 88 healthy women and 74 women with SSc. Male Mc was quantified by DYS14 real-time PCR in blood samples from 58 women who had previously given birth to at least one male child. Furthermore, eight HLA-G 5′URR/3′UTR polymorphisms, previously described as influencing HLA-G expression, were performed on DNA samples from 96 healthy women and 106 women with SSc. Peripheral sHLA-G was at lower concentration in plasma from SSc (76.2 ± 48.3 IU/mL) compared to healthy women (117.5 ± 60.1 IU/mL, p

In a pilot ProtoArray analysis, we identified 6 proteins out of 9483 recognized by autoantibodies (AAb) from patients with systemic sclerosis (SSc). We further investigated the 6 candidates by ELISA on hundreds of controls and patients, including patients with Systemic Lupus Erythematosus (SLE), known for high sera reactivity and overlapping AAb with SSc. Only 2 of the 6 candidates, Ephrin type-B receptor 2 (EphB2) and Three prime Histone mRNA EXonuclease 1 (THEX1), remained significantly recognized by sera samples from SSc compared to controls (healthy or with rheumatic diseases) with, respectively, 34% versus 14% (P = 2.10-4) and 60% versus 28% (P = 3.10-8). Above all, EphB2 and THEX1 revealed to be mainly recognized by SLE sera samples with respectively 56%, (P = 2.10-10) and 82% (P = 5.10-13). As anti-EphB2 and anti-THEX1 AAb were found in both diseases, an epitope mapping was realized on each protein to refine SSc and SLE diagnosis. A 15-mer peptide from EphB2 allowed to identify 35% of SLE sera samples (N = 48) versus only 5% of any other sera samples (N = 157), including SSc sera samples. AAb titers were significantly higher in SLE sera (P

Autoimmune diseases, including rheumatoid arthritis (RA) and systemic sclerosis (SSc) are characterized by a strong genetic susceptibility from the Human Leucocyte Antigen (HLA) locus. Additionally, disorders of epigenetic processes, in particular non-random X chromosome inactivation (XCI), have been reported in many female-predominant autoimmune diseases. Here we test the hypothesis that women with RA or SSc who are strongly genetically predisposed are less susceptible to XCI bias.Using methylation sensitive genotyping of the androgen receptor (AR) gene, XCI profiles were performed in peripheral blood mononuclear cells from 161 women with RA, 96 women with SSc and 100 healthy women. HLA-DRB1 and DQB1 were genotyped. Presence of specific autoantibodies was documented for patients. XCI skewing was defined as having a ratio ≥ 80:20 of cells inactivating the same X chromosome.110 women with RA, 68 women with SSc, and 69 controls were informative for the AR polymorphism. Among them 40.9% of RA patients and 36.8% of SSc patients had skewed XCI compared to 17.4% of healthy women (P = 0.002 and 0.018, respectively). Presence of RA-susceptibility alleles coding for the "shared epitope" correlated with higher skewing among RA patients (P = 0.002) and such correlation was not observed in other women, healthy or with SSc. Presence of SSc-susceptibility alleles did not correlate with XCI patterns among SSc patients.Data demonstrate XCI skewing in both RA and SSc compared to healthy women. Unexpectedly, skewed XCI occurs more often in women with RA carrying the shared epitope, which usually reflects severe disease. This reinforces the view that loss of mosaicism in peripheral blood may be a consequence of chronic autoimmunity.

Patients with end stage renal diseases (ESRD) are generally tested for donor chimerism after kidney transplantation for tolerance mechanism purposes. But, to our knowledge, no data are available on natural and/or iatrogenic microchimerism (Mc), deriving from pregnancy and/or blood transfusion, acquired prior to transplantation. In this context, we tested the prevalence of male Mc using a real time PCR assay for DYS14, a Y-chromosome specific sequence, in peripheral blood mononuclear cells (PBMC) from 55 women with ESRD, prior to their first kidney transplantation, and compared them with results from 82 healthy women. Male Mc was also quantified in 5 native kidney biopsies obtained two to four years prior to blood testing and in PBMC from 8 women collected after female kidney transplantation, several years after the initial blood testing. Women with ESRD showed statistically higher frequencies (62%) and quantities (98 genome equivalent cells per million of host cells, gEq/M) of male Mc in their PBMC than healthy women (16% and 0.3 gEq/M, p

Although many studies have analyzed HLA allele frequencies in several ethnic groups in patients with scleroderma (SSc), none has been done in French Caucasian patients and none has evaluated which one of the common amino acid sequences, (67)FLEDR(71), shared by HLA-DRB susceptibility alleles, or (71)TRAELDT(77), shared by HLA-DQB1 susceptibility alleles in SSc, was the most important to develop the disease. HLA-DRB and DQB typing was performed for a total of 468 healthy controls and 282 patients with SSc allowing FLEDR and TRAELDT analyses. Results were stratified according to patient's clinical subtypes and autoantibody status. Moreover, standardized HLA-DRß1 and DRß5 reverse transcriptase Taqman PCR assays were developed to quantify ß1 and ß5 mRNA in 20 subjects with HLA-DRB1*15 and/or DRB1*11 haplotypes. FLEDR motif is highly associated with diffuse SSc (χ(2) = 28.4, p