scholarly journals High levels of gut-homing immunoglobulin A–positive+B lymphocytes support the pathogenic role of intestinal mucosal hyperresponsiveness in immunoglobulin A nephropathy patients

2020 ◽  
Author(s):  
Fabio Sallustio ◽  
Claudia Curci ◽  
Nada Chaoul ◽  
Giulia Fontò ◽  
Gabriella Lauriero ◽  
...  
Keyword(s):  
B Cells ◽  
B Lymphocytes ◽  
Immunoglobulin A ◽  
Serum Levels ◽  
Memory B Cells ◽  
Immunoglobulin A Nephropathy ◽  
Pathogenic Role ◽  
Significant Difference ◽  
Activated B Cells

Abstract Background Immunoglobulin A nephropathy (IgAN) is the most frequent primary glomerulonephritis. The role of the microbiota and mucosal immunity in the pathogenesis of IgAN remains a key element. To date, the hypothetical relationship between commensal bacteria, elevated tumour necrosis factor (TNF) superfamily member 13 [also known as B-cell activating factor (BAFF)] levels, perturbed homoeostasis of intestinal-activated B cells and intestinal IgA class switch has not been clearly shown in IgAN patients. Methods We studied the intestinal–renal axis connections, analysing levels of BAFF, TNF ligand superfamily member 13 (APRIL) and intestinal-activated B cells in IgAN patients, healthy subjects (HSs) and patients with non-IgA glomerulonephritides. Results IgAN patients had increased serum levels of BAFF cytokine, correlating with higher amounts of five specific microbiota metabolites, and high APRIL cytokine serum levels. We also found that subjects with IgAN have a higher level of circulating gut-homing (CCR9+ β7 integrin+) regultory B cells, memory B cells and IgA+ memory B cells compared with HSs. Finally, we found that IgAN patients had high levels of both total plasmablasts (PBs) and intestinal-homing PBs. Interestingly, PBs significantly increased in IgAN but not in patients with other glomerulonephritides. Conclusions Our results demonstrate a significant difference in the amount of intestinal-activated B lymphocytes between IgAN patients and HSs, confirming the hypothesis of the pathogenic role of intestinal mucosal hyperresponsiveness in IgAN. The intestinal–renal axis plays a crucial role in IgAN and several factors may contribute to its complex pathogenesis and provide an important area of research for novel targeted therapies to modulate progression of the disease.

Different Expression of FcgammaRIIb in Chronic Lymphocytic Leukemia and Human Normal B Lymphocytes

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 3134-3134
Author(s):  
Carol Moreno ◽  
Rajendra Damle ◽  
Sonia Jansa ◽  
Gerardo Ferrer ◽  
Pau Abrisqueta ◽  
...  
Keyword(s):  
B Cells ◽  
Chronic Lymphocytic Leukemia ◽  
B Cell ◽  
B Lymphocytes ◽  
Surface Membrane ◽  
Memory B Cells ◽  
Lymphocytic Leukemia ◽  
Cd38 Expression ◽  
B Cell Subsets

Abstract The Fcgamma receptors (FcγRs) are a family of molecules that modulate immune responses. FcγRIIb is an inhibitory FcγR that bears immunoreceptor tyrosine-based inhibitory motifs which transduce inhibitory signals on coligation with the surface membrane Ig of the B-cell antigen receptor (BCR). The role of FcγRIIb in controlling B cell activation through inhibition of BCR signaling has been extensively studied in animal models. Nevertheless, data on FcγRIIb are scant in human normal and neoplastic B cells, this being due to the lack of a specific antibody for human FcγRIIb. Consequently, there is little information on this receptor in chronic lymphocytic leukemia (CLL). Considering the activated nature of CLL cells and the central role of the BCR in the biology of the disease, studies of FcγRs are warranted. We used a novel specific mAb directly conjugated with Alexa 488 fluorophore that solely reacts with the human FcγRIIb (MacroGenics, Inc.) to investigate the receptors expression on CLL and normal human B cells. The study population included 84 patients with CLL and 24 age- and sex-matched controls. FcγRIIb expression was assessed as the mean fluorescence intensity (MFI) of surface membrane staining. In CLL cells, FcγRIIb was measured on CD19+CD5+ cells in combination with CD38, CD49d or CD69. Normal B cells were immunostained for CD19, CD5, IgD and CD38 expression and B cell subsets: naïve (IgD+CD38−), activated (IgD+CD38+) and memory B cells (IgD−CD38−) were studied for their relative expression of FcγRIIb. FcγRIIb expression was found significantly higher in naïve B cells compared to activated and memory B cells [median MFI: 17420 (11960–21180) vs. 11.140 (7899–16970) and 11.830 (6984–17100); p<0.001]. Significant differences were also observed between CD5− and CD5+ normal B cells. In contrast, FcγRIIb expression was lower in CLL cells than in CD5+ and CD5− normal B lymphocytes [median MFI: 6901(1034–42600), 10180 (5856–14820) and 12120 (7776–16040); p<0.05)]. Interestingly, FcγRIIb expression was variable within individual CLL clones, this being higher in CD38+ and CD49d+ cells than in CD38− and CD49d− cells (p<0.05). Furthermore, the highest density of FcγRIIb was observed on those cells which coexpressed CD38 and CD49d. In contrast, no significant differences were observed between FcγRIIb and the expression of the activation antigen CD69. Although CD69 and CD38 expression was significantly higher on unmutated IGHV cases, no correlation was found between FcγRIIb levels and IGHV mutational status. Similarly, there was no correlation between FcγRIIb and other poor prognostic variables such as ZAP-70 (≥20%), CD38 (≥ 30%) or high risk cytogenetics. Nevertheless, cases with ≥ 30% CD49d+ cells had higher FcγRIIb expression than those with <30% CD49d+ cells (p=0.006). The findings presented in this study suggest a hierarchy of FcγRIIb expression in normal B-cells, CLL cells and their subpopulations: circulating normal CD5− B cells > circulating normal CD5+ B cells > circulating CD5+ CLL B cells. In addition, although FcγRIIb is present on all normal B cell subsets its expression is higher in naïve B cells. Furthermore, in CLL FcγRIIb density is greater in CD38+ and CD49d+ cells within the clone. Although CD49d and FcγRIIb on CLL clones is linked in a direct manner, there is no relationship with FcγRIIb density and IGHV mutations, ZAP-70, CD38 and unfavorable cytogenetic markers. Finally, the relationship between FcγRIIb expression on CLL cells and functional responses to BCR and other receptor-mediated signals deserve further investigation.

scholarly journals Probiotics Stimulate Production of Natural Antibodies in Chickens

2006 ◽  
Vol 13 (9) ◽  
pp. 975-980 ◽  
Author(s):  
Hamid R. Haghighi ◽  
Jianhua Gong ◽  
Carlton L. Gyles ◽  
M. Anthony Hayes ◽  
Huaijun Zhou ◽  
...  
Keyword(s):  
Immune Response ◽  
Immunoglobulin A ◽  
Serum Levels ◽  
Natural Antibodies ◽  
Commensal Bacteria ◽  
Lymphoid Tissues ◽  
Alpha Toxin ◽  
Igg Antibodies ◽  
Significant Difference

ABSTRACT Commensal bacteria in the intestine play an important role in the development of immune response. These bacteria interact with cells of the gut-associated lymphoid tissues (GALT). Among cells of the GALT, B-1 cells are of note. These cells are involved in the production of natural antibodies. In the present study, we determined whether manipulation of the intestinal microbiota by administration of probiotics, which we had previously shown to enhance specific systemic antibody response, could affect the development of natural antibodies in the intestines and sera of chickens. Our findings demonstrate that when 1-day-old chicks were treated with probiotics, serum and intestinal antibodies reactive to tetanus toxoid (TT) and Clostridium perfringens alpha-toxin in addition to intestinal immunoglobulin A (IgA) reactive to bovine serum albumin (BSA) were increased in unimmunized chickens. Moreover, IgG antibodies reactive to TT were increased in the intestines of probiotic-treated chickens compared to those of untreated controls. In serum, IgG and IgM reactive to TT and alpha-toxin were increased in probiotic-treated, unimmunized chickens compared to levels in untreated controls. However, no significant difference in serum levels of IgM or IgG response to BSA was observed. These results are suggestive of the induction of natural antibodies in probiotic-treated, unimmunized chickens. Elucidating the role of these antibodies in maintenance of the chicken immune system homeostasis and immune response to pathogens requires further investigation.

Abatacept Reduces Levels of Switched Memory B Cells, Autoantibodies, and Immunoglobulins in Patients with Rheumatoid Arthritis

2014 ◽  
Vol 41 (4) ◽  
pp. 666-672 ◽  
Author(s):  
Mirko Scarsi ◽  
Lucia Paolini ◽  
Doris Ricotta ◽  
Antonio Pedrini ◽  
Silvia Piantoni ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
B Cells ◽  
B Cell ◽  
B Lymphocytes ◽  
Cell Activation ◽  
Serum Levels ◽  
Memory B Cells ◽  
Cell Phenotype ◽  
B Cell Activation ◽  
Switch Memory

Objective.Abatacept (ABA) is a chimeric molecule, able to block the CD28-mediated costimulatory pathway. To evaluate the hypothesis that, through this mechanism of action, ABA may down-modulate the immune responses of B lymphocytes in rheumatoid arthritis (RA), we investigated the serum levels of immunoglobulins (Ig), free light chains (FLC), anticitrullinated protein antibodies (ACPA), and rheumatoid factor (RF), as well as the number of B lymphocytes differentiated into post-switch memory cells in patients treated with ABA.Methods.The serum levels of Ig, FLC, different ACPA, RF isotypes, and the B cell phenotype were longitudinally evaluated in 30 patients with RA treated with ABA.Results.At baseline, the proportion of total and post-switch memory B cells was lower in RA than in healthy individuals. After 6 months of ABA treatment we observed significant reductions of serum levels of IgG, IgA, and IgM, as well as FLC, with a normalization in many patients who had initially abnormal values. A significant reduction of the titers of IgG- and IgA-ACPA, as well as of IgM-, IgA-, and IgG-RF was also observed. A decrease of autoantibodies below the upper limits of normal values was found in 2 of 26 patients (8%) initially seropositive for IgG-ACPA, 1 of 14 (7%) for IgA-ACPA, 5 of 22 (23%) for IgM-RF, 7 of 22 (30%) for IgA-RF, and 5 of 16 (31%) for IgG-RF. After treatment, the proportion of circulating post-switch memory B cells was also further significantly decreased.Conclusion.ABA treatment in patients with RA can reduce signs of polyclonal B cell activation, inducing a trend toward normalization of serum levels of different classes of Ig and of FLC, decreasing titers of ACPA and RF, and percentages of post-switch memory B cells.

scholarly journals Chronic meningococcaemia and immunoglobulin A deficiency

2010 ◽  
Vol 59 (11) ◽  
pp. 1375-1378 ◽  
Author(s):  
Arnaud Theulin ◽  
Murielle Rondeau-Lutz ◽  
Cornelia Kuhnert ◽  
Julien Boileau ◽  
Jean-Christophe Weber
Keyword(s):  
B Cells ◽  
Neisseria Meningitidis ◽  
Common Variable Immunodeficiency ◽  
Clinical Presentation ◽  
Immunoglobulin A ◽  
Iga Deficiency ◽  
Memory B Cells ◽  
Igm Deficiency ◽  
Common Variable

Chronic meningococcaemia is an unusual clinical presentation of Neisseria meningitidis infection. We describe the case of a patient, who presented with total IgA deficiency and partial IgM deficiency with a low switched memory B cells count, suggestive of a borderline form of common variable immunodeficiency (CVID). The role of IgA in the protection against Neisseria meningitidis, and the link between IgA deficiency and CVID are discussed.

Modulation of the microbiota by oral antibiotics treats immunoglobulin A nephropathy in humanized mice

2018 ◽  
Vol 34 (7) ◽  
pp. 1135-1144 ◽  
Author(s):  
Jonathan M Chemouny ◽  
Patrick J Gleeson ◽  
Lilia Abbad ◽  
Gabriella Lauriero ◽  
Erwan Boedec ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Antibiotic Treatment ◽  
Bacterial Load ◽  
Immunoglobulin A ◽  
Serum Levels ◽  
Immunoglobulin A Nephropathy ◽  
Intestinal Tissue ◽  
Humanized Mouse Model ◽  
Iga Production

Abstract Background Immunoglobulin A nephropathy (IgAN) is the most common primary glomerulonephritis worldwide. IgA is mainly produced by the gut-associated lymphoid tissue (GALT). Both experimental and clinical data suggest a role of the gut microbiota in this disease. We aimed to determine if an intervention targeting the gut microbiota could impact the development of disease in a humanized mouse model of IgAN, the α1KI-CD89Tg mice. Methods Four- and 12-week old mice were divided into two groups to receive either antibiotics or vehicle control. Faecal bacterial load and proteinuria were quantified both at the beginning and at the end of the experiment, when blood, kidneys and intestinal tissue were collected. Serum mouse immunoglobulin G (mIgG) and human immunoglobulin A1 (hIgA1)-containing complexes were quantified. Renal and intestinal tissue were analysed by optical microscopy after haematoxylin and eosin colouration and immunohistochemistry with anti-hIgA and anti-mouse CD11b antibodies. Results Antibiotic treatment efficiently depleted the faecal microbiota, impaired GALT architecture and impacted mouse IgA production. However, while hIgA1 and mIgG serum levels were unchanged, the antibiotic treatment markedly prevented hIgA1 mesangial deposition, glomerular inflammation and the development of proteinuria. This was associated with a significant decrease in circulating hIgA1–mIgG complexes. Notably, final faecal bacterial load strongly correlated with critical clinical and pathophysiological features of IgAN such as proteinuria and hIgA1–mIgG complexes. In addition, treatment with broad-spectrum antibiotics reverted established disease. Conclusions These data support an essential role of the gut microbiota in the generation of mucosa-derived nephrotoxic IgA1 and in IgAN development, opening new avenues for therapeutic approaches in this disease.

scholarly journals Role of vitamin D serum levels in prevention of primary and recurrent melanoma

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. Lombardo ◽  
A. Vigezzi ◽  
G. Ietto ◽  
C. Franchi ◽  
V. Iori ◽  
...  
Keyword(s):  
Vitamin D ◽  
Serum Levels ◽  
Mitotic Rate ◽  
Control Group ◽  
Healthy Population ◽  
Histological Subtype ◽  
Melanoma Diagnosis ◽  
Significant Difference ◽  
Tumour Location

AbstractPatients afflicted with melanoma show lower vitamin D serum levels (VDSL) than the healthy population. This hypothesis agrees with its well-known antiproliferative features. An observational study was carried out to collect VDSL in patients suffering from melanoma. Our aim was to identify a potential connection between low VDSL and the risk to incur melanoma. Furthermore, we studied the association between VDSL at the diagnosis of melanoma and other germane prognostic factors. The population held in regard was composed of 154 patients with a diagnosis of melanoma between 2016 and 2019. These patients were retrospectively collected from our follow-up storage. We compared VDSL to clinical and pathological parameters (age, sex, tumour location, Breslow’s depth, Clark’s level, histological subtype, ulceration, et aliqua). Moreover, we recruited a control group with negative melanoma history. Mean and median of VDSL were significantly lower in the melanoma group. Instead, we found a negative association between melanoma and VDSL > 30 ng/L (OR 0.11; p < 0.0001). No correlation between VDSL and both Breslow’s depth and Clark’s level was discovered, but the VDSL comparison between thin (depth ≤ 1 mm) and thick tumours (depth > 1 mm) revealed a statistically significant difference (21.1 ± 8.2 ng/L vs 17.8 ± 8.1; p = 0.01). Moreover, VDSL were significantly lower in melanomas with mitotic rate ≥ 1/mm2 (22.1 ± 8.3 ng/L; p < 0007). Nevertheless, no connection was found between VDSL and both ulceration and positive sentinel nodes (p = 0.76; p = 0.74). Besides, our study revealed no association between VDSL and histological subtype (p = 0.161). Lower VDSL correlate with thick and high mitotic rate tumours. Future prospective studies would investigate if appropriate upkeep of suitable VDSL can decrease the risk of primary and recurrent melanoma diagnosis.

The role of memory B cells in immunity after vaccination

2009 ◽  
Vol 19 ◽  
pp. S160-S162
Author(s):  
Rita Carsetti ◽  
Alberto E. Tozzi
Keyword(s):  
B Cells ◽  
Memory B Cells
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