Regina Peri

Intravenous immunoglobulin therapy affects T regulatory cells by increasing their suppressive function.

Intravenous Ig therapy (IVIg) is reported to be a useful regimen in treating autoimmune diseases. In this study, we asked whether IVIg (in vitro) could increase the expression of TGF-β, IL-10, and the transcription factor FoxP3 in T regulatory (Treg) cells, and the idea that IVIg could enhance suppressive properties of these cells. CD4+ T cells from 12 healthy individuals were cultured in the presence or absence of IVIg vs human control IgG during 16, 24, and 36 h. Using FACS analysis and gating on CD4+CD25high Treg cells, we assessed the expression of intracellular TGF-β, IL-10, and FoxP3. In addition, the production of TNF-α by stimulated CD4+ T cells alone or in culture with CD25+ by itself or together with IVIg was also assessed. The presence of IVIg with Treg cells in culture significantly increased the intracellular expression of TGF-β (17.7 ± 8.5% vs 29.8 ± 13%; p = 0.02), IL-10 (20.7 ± 4.7% vs 34.2 ± 5.2%; p = 0.008) and FoxP3 (20.8 ± 5.2% vs 33.7 ± 5.9%; p = 0.0006) when compared with cells cultured alone or with control human IgG. The suppressive effect of CD4+CD25+ T cells presented as the decrease of TNF-α production by stimulated CD4+CD25− (effector T cells) was further increased by adding IVIg to cell culture. We hereby demonstrate an additional mechanism by which IVIg could maintain self-tolerance and decrease immune-mediated inflammation.

Regulatory T cells (CD4+CD25brightFoxP3+) expansion in systemic sclerosis correlates with disease activity and severity

BACKGROUND The role and function of T regulatory (Treg) cells have not been fully investigated in patients with systemic sclerosis (SSc). METHODS Ten patients with SSc donated 20ml of peripheral blood. Activity (Valentini) and severity (Medsger) scores for SSc were calculated for all patients. Healthy volunteers (controls) were matched to each patient by gender and age. CD4(+) cells were separated using the MACS system. The numbers of Treg cells were estimated by flow cytometry after staining for CD4, CD25, and FoxP3 and calculated as patient-to-control ratio separately for each experiment. Correlations with activity and severity indices of the disease were performed. Twenty-four-hour production of TGF-beta and IL-10 by activated CD4(+) cells was measured by ELISA in culture supernatants. RESULTS The numbers of Treg cells, expressed as patient-to-control ratio, correlated significantly with both activity and severity indices (r=0.71, p=0.034 and r=0.67, p=0.044, respectively). ELISA-measured production of TGF-beta and IL-10 by CD4(+) cells was similar in patients and controls. CONCLUSIONS Increased numbers of Treg cells are present in patients with SSc, correlating with activity and severity of the disease. This expansion of Treg cells was not accompanied, however, by heightened TGF-beta or IL-10 production. Further studies to elaborate the causes and functional significance of Treg cell expansion in SSc are needed.

Immunization of pregnant women against pertussis: the effect of timing on antibody avidity.

BACKGROUND The Centers for Disease Control and Prevention recommend tetanus-diphteria-acellular pertussis (Tdap) immunization during pregnancy, preferably at 27-36 weeks gestation. AIMS First, to assess the relative avidity index (RAI) of umbilical cord immunoglobulin G (IgG) to pertussis toxin (PT) for newborns of women immunized with Tdap during late pregnancy as compared to unimmunized women. Second, to assess whether there is a preferential period of gestational Tdap immunization that provides the highest RAI of umbilical cord IgG to PT. METHODS RAI of IgG to PT was assessed via an adapted ELISA using NH4SCN as a dissociating agent. RESULTS We found that newborns of women immunized with Tdap during late pregnancy (n=52) had higher mean RAI of umbilical cord IgG to PT than those of unimmunized women (n=8), 73.77%±12.08 (95% CI, 70.41-77.13) vs. 50.23%±21.32 (95% CI, 32.41-68.06), p<0.001. Further, the RAI of umbilical cord IgG to PT was significantly higher in newborns of women immunized at 27-30(+6) weeks gestation (n=20) when compared with newborns of women immunized at 31-36 weeks (n=22) and >36 weeks (n=7), 79.53%±5.61 (95% CI, 76.91-82.16) vs. 71.56%±12.58 (95% CI, 65.98-77.14) vs. 63.93%±17.98 (95% CI, 47.31-80.56), p<0.03. CONCLUSION Gestational Tdap immunization between 27 and 30(+6) weeks resulted in the highest avidity of IgG to PT conveyed at delivery as compared with immunization beyond 31 weeks gestation. Future studies should be conducted to confirm our findings to optimize pertussis-controlling strategies.

The induction of breast milk pertussis specific antibodies following gestational tetanus–diphtheria–acellular pertussis vaccination

BACKGROUND Center for Disease Control and Prevention recommends vaccination of pregnant women with tetanus-diphtheria-acellular pertussis (Tdap). AIM To measure pertussis specific antibodies, total protein and their ratio in breast milk following gestational Tdap vaccination. METHODS Women who received Tdap after the 20th week of pregnancy were recruited and unvaccinated women served as controls. Breast milk total protein, immunoglobulin A (IgA) to pertussis toxin (PT), filamentous hemagglutinin (FHA) and immunoglobulin G (IgG) to PT, FHA and pertactin (PRN) were measured. To overcome the dilution that occurs in the transition from colostrum to mature breast milk, we calculated pertussis specific antibody to total protein ratio. RESULTS Pertussis specific IgA was the predominant pertussis immunoglobulin in the colostrum of Tdap vaccinated women with the geometric mean concentrations (GMCs) of IgA to FHA higher than for IgA to PT, 24.12 ELISA units/milliliter (EU/mL) vs. 8.18EU/mL, respectively, p<0.004. There were differences between the vaccinated women and controls in the GMCs of IgA to FHA and IgG to PRN in the colostrum, 24.12EU/mL vs. 6.52EU/mL, p=0.01 and 2.46EU/mL vs. <0.6EU/mL, p=0.03, respectively. The GMCs of total protein showed significant decline over 8 weeks in the vaccinated women and controls, p<0.004. Among vaccinated women, there was significant decline in the GMCs of IgA to PT and FHA over 8 weeks, p<0.001. The geometric mean ratio of IgA to FHA to total protein also declined significantly over 8 weeks in the vaccinated women, p<0.01, demonstrating a true decrease, however, pertussis IgA was measurable at 8 weeks. CONCLUSIONS Select colostrum pertussis antibody levels were significantly higher among women vaccinated with Tdap during pregnancy compared with unvaccinated women. Among vaccinated women, maximal levels of pertussis specific IgA were in the colostrum but still detected at 8 weeks. Lactation may augment infants protection against pertussis.

Enhanced Apoptosis of Peripheral CD5-Negative B Lymphocytes from Chronically Hepatitis C Virus-Infected Patients: Reversal after Antiviral Treatment

ABSTRACT Whereas enhanced peripheral T-cell apoptosis and its association with autoimmunity have recently been reported, the apoptotic status of peripheral B cells in chronic hepatitis C virus (HCV) infection remains ambiguous. We therefore sought to investigate the sensitivity of peripheral B cells to apoptosis and to assess the possible benefits of antiviral treatment in mitigating these effects. Spontaneous apoptosis, the extent of apoptosis rescue, and NF-κB expression in peripheral B cells were studied in patients with chronic HCV infections (group 1), in sustained responders after antiviral treatment (group 2), and in healthy controls (group 3). For group 1, spontaneous B-cell apoptosis was increased (26% ± 4.6%) and apoptosis rescue was altered (39%) compared to group 3 (18% ± 5% and 50%, respectively; P = 0.001). In contrast, apoptosis and apoptosis rescue were similar for groups 2 and 3. Enhanced B-cell apoptosis was associated with decreased NF-κB expression and was found only in CD5-negative (CD5neg) B cells, whereas CD5pos cells were apoptosis resistant. Chronic HCV infection is associated with enhanced peripheral B-cell apoptosis and decreased apoptosis rescue. Successful antiviral treatment reverses these abnormalities to the levels seen in healthy individuals. The relative resistance of the CD5pos B-cell subpopulation to apoptosis may play a role in HCV-related autoimmunity and lymphoproliferation.

The Expansion of CD25highIL-10highFoxP3high B Regulatory Cells Is in Association with SLE Disease Activity

B regulatory cells (Bregs) belong to a subgroup of activated B cells tasked with maintaining self-tolerance and preventing autoimmunity. While sharing similar regulatory mechanisms such as IL-10 dependency, they also defer in exhibiting their suppressive effects by expressing Fas-Ligand, TGF-beta, and PDL-1. In this study we show, for the first time, the expansion of CD25highFoxP3high Bregs in systemic lupus erythematosus (SLE) patients compared to healthy individuals (18.5 ± 3.052% versus 11.0 ± 1.654%, p < 0.001, resp.). This expansion was also shown to correlate with SLE disease activity (r = 0.75). In addition, CD25highFoxP3high Bregs were also IL-10high expressing and further expanded when stimulated with semaphorin 3A. In sum we show that CD25highFoxP3high are an additional subtype of Bregs, involved in regulating SLE disease activity. Being IL-10 expressing, we may assume that they are one of the sources of increased serum IL-10 in SLE patients. Further studies are required in order to assess the relation between high serum IL-10 and CD25highFoxP3high Breg cells.

A regulatory role for CD72 expression on B cells in systemic lupus erythematosus.

BACKGROUND B regulatory cells and their regulatory products/markers, such us semaphorin 3A (sema3A) and its receptor NP-1, FcγIIB, IL-10, and others, act at the very base of self-tolerance, maintenance, and prevention of autoimmune disease development. OBJECTIVES The aim of the present study was to assess the involvement of CD72, a regulatory receptor on B cells, in systemic lupus erythematosus (SLE). In addition, the potential of soluble sema3A in enhancing the expression of CD72 on B cells of SLE patients was investigated. RESULTS CD72 expression on activated B cells of SLE patients was significantly lower than that of normal controls. This lower expression of CD72 in SLE patients correlated inversely with SLE disease activity and was associated with lupus nephritis, the presence of anti-dsDNA antibodies, and low levels of complement. Co-culture of purified B cells from healthy controls with condition-media containing recombinant sema3A resulted in significant enhancement of CD72. Similar enhancement of CD72 on activated B cells from SLE patients, though significant, was still lower than in normal individuals. CONCLUSIONS The lower expression of CD72 on activated B cells from SLE patients correlates with SLE disease activity, lupus nephritis, the presence of anti-dsDNA antibodies, and low levels of complement. The improvement of CD72 expression following the addition of soluble semaphorin 3A suggests that CD72 may be useful as a biomarker to be followed during the treatment of SLE.

Higher expression of latency-associated peptide on the surface of peripheral blood monocytes in patients with rheumatoid arthritis may be protective against articular erosions.

Latency-associated peptide (LAP) forms small latent complexes with transforming growth factor beta 1 (TGF-β1). TGF-β–LAP complexes can be detected on the surfaces of immune cells and have been recently shown to play a role in immune regulation through TGF-β1-mediated functions. A study was undertaken to investigate the correlation of LAP expression on the surface of immune cells and presence of articular erosions in patients with rheumatoid arthritis (RA). Venous blood was obtained from patients with severe RA as well as from healthy control subjects. Surface expression of LAP on peripheral blood mononuclear cells was analyzed by flow cytometry, measured as flow cytometric intensity separately on CD14+ and CD14− cells, and compared between RA patients and healthy subjects. Patients with RA demonstrated higher surface expression of LAP on both CD14+ and CD14− mononuclear cells than healthy individuals. Patients with erosive RA had significantly reduced intensity of anti-LAP staining on the CD14+ cells when compared to RA patients without erosions (p = 0.01). The intensity of anti-LAP staining on CD14− cells was not different between groups of RA patients. Higher expression of LAP on the surface of the cells of monocyte lineage may be protective of formation of articular erosions in RA. Further studies are needed to elaborate the mechanism of this phenomenon.

CD14brightLAP+ mononuclear cells in peripheral blood positively correlate with BASRI scores in patients with ankylosing spondylitis: A pilot study

Joint Bone Spine - In Press.Proof corrected by the author Available online since mercredi 25 juillet 2012

Production of bone formation-regulating factors by osteoclasts in vitro does not correlate with the radiographic disease progression in patients with ankylosing spondylitis.

Joint Bone Spine - In Press.Proof corrected by the author Available online since mercredi 7 octobre 2015