scholarly journals BCR analysis of single-sorted, putative IgE+ memory B cells in food allergy: an ephemeral existence?

2019 ◽  
Author(s):  
Rodrigo Jiménez-Saiz ◽  
Yosef Ellenbogen ◽  
Kelly Bruton ◽  
Paul Spill ◽  
Doron D. Sommer ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
B Cells ◽  
Allergic Disease ◽  
Peripheral Circulation ◽  
Memory B Cells ◽  
Healthy Donors ◽  
Bona Fide ◽  
The Subject ◽  
Flow Cytometry Protocol

AbstractImmunoglobulin (Ig) E is the critical effector molecule in allergic reactions. Consequently, research efforts to understand the biology of IgE-expressing cells is of paramount importance. In particular, the role of IgE+ memory B cells (MBCs) in the perpetuation of allergic reactivity has been the subject of intense research. Studies in mice have convincingly established that IgE+ B cells are rare and transient and, therefore, an unlikely candidate to maintain allergic disease. In contrast, IgE+ MBCs have been detected by flow cytometry in the sputum and peripheral blood of humans and have been proposed as a clinical marker of allergic disease. We established a method to genetically validate, at the single-cell level, the putative IgE+ MBCs identified by flow cytometry from humans. We, then used this information to develop an enhanced flow cytometry protocol that more accurately identifies bona fide IgE+ MBCs. We found that IgE+ MBCs were detected in some patients with atopic dermatitis, but at a frequency that was ~100 times lower than previously reported. We also found that IgE+ MBCs were undetectable in PBMCs from peanut allergic patients. These findings provide tools to identify bona fide IgE+ MBCs, demonstrate their extreme rarity in circulation and are consistent with the lack of a central role for IgE+ MBCs in the maintenance of allergic sensitivity.One Sentence SummaryThe frequency of IgE+ MBCs in the peripheral circulation of humans is orders of magnitude lower than previously reported and comparable between allergic and healthy donors, which cautions about the clinical utility of their assessment.

P0523PROTECTIVE ROLE OF REGULATORY B CELLS ON THE RENAL TISSUE REPAIRMEN AFTER ISCHEMIA REPERCUSSION INJURY

2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Yokota Yunosuke ◽  
Goh Kodama ◽  
Sakuya Itou ◽  
Yosuke Nakayama ◽  
Nobukazu Komatsu ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Renal Function ◽  
B Cells ◽  
Interleukin 10 ◽  
Renal Tissue ◽  
Protective Role ◽  
Regulatory B Cells ◽  
Tubulointerstitial Injury ◽  
Iri Model

Abstract Background and Aims Acute kidney injury (AKI), even if followed by renal recovery, is a risk factor for the future development of chronic kidney disease (CKD) and end- stage renal disease. It has been postulated that interleukin-10 (IL-10)-producing Regulatory B cells (Breg) play an important role for the tissue repairment in several tissues and organs. Basically, protective role of Breg has been reported in inflammatory bowel disease. In the kidney, it has been shown that IL-10 suppresses renal function decline and improves renal prognosis in IRI model, a typical model of AKI. However, the identity of Breg in the kidney and their origin have not been clarified. Further, how the Breg works during the transition from AKI to CKD is not known. Therefore, first we investigated whether Breg existed in renal tissue on the progression from AKI to CKD in IRI model mice. Further, we performed splenectomy, and examined the renal injury, Breg, and plasma IL-10 levels in this model. Method To examine the existence of Breg in the kidney of IRI model, we used 8-10 weeks-old GFP / IL-10 mice based on C57BL / 6J mice. They are reporter mice for IL-10 producing cells, and can visualize IL-10 producing cells under a fluorescence microscope without fluorescent immunostaining. We prepared following three groups, sham, IRI (unilateral), and IRI + SN (splenectomy) groups. Mice were anesthetized with chloral hydrate (4 g/kg,, intraperitoneal). After making a midline incision, exposed a blood vessel of the left renal pedicles and clamped it for 30 min by clips. one day, 7 days, and 14 days after the surgery, mice were sacrificed, and renal function and plasma IL-10 levels as well as tissue damages by PAS and Masson’s Trichrome staining were assessed. Tissue IL-10-producing cells were detected by flow cytometry. Results There was no difference of plasma IL-10 levels and renal tubulointerstitial injury in IRI group and IRI+SN group on day 1 after IRI. However, on day 7 and day 14, plasma IL-10 levels became gradually higher in IRI group, and SN decreased the increase in IL-10 levels. Tubulointerstitial injury was induced by IRI and SN further worsened tubular damages. Serum Cr and BUN levels were not different in three groups due to normal right kidney. On day 1, number of IL-10-producing B cells increased in the spleen and renal medulla in IRI group confirmed by flow cytometry, which was completely diminished by SN, suggesting that origin of the infiltrated Breg might be spleen, thereby being involved in the protective role in IRI injury in the kidney. Conclusion We report for the first time that Breg might be recruited from spleen by AKI, which may be one of the mechanisms to prevent the progression to CKD.

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

Role of Tonsillar IgD+CD27+ Memory B Cells in Humoral Immunity Against Pneumococcal Infection

2006 ◽  
Vol 67 (12) ◽  
pp. 966-975 ◽  
Author(s):  
Masahiro Takizawa ◽  
Kazuo Sugane ◽  
Kazunaga Agematsu
Keyword(s):  
B Cells ◽  
Humoral Immunity ◽  
Pneumococcal Infection ◽  
Memory B Cells

scholarly journals IgG+ memory B cells: Friends or foes in allergic disease?

2020 ◽  
Vol 146 (1) ◽  
pp. 77-79
Author(s):  
Hannah J. Gould ◽  
Louisa K. James
Keyword(s):  
B Cells ◽  
Allergic Disease ◽  
Memory B Cells

Biological Sequelae of TRAF2 Downregulation in Waldenstrom Macroglobulinemia Cells.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 3526-3526
Author(s):  
Xavier Leleu ◽  
Lian Xu ◽  
Zachary R. Hunter ◽  
Sophia Adamia ◽  
Evdoxia Hatjiharissi ◽  
...  
Keyword(s):  
Gene Expression ◽  
B Cells ◽  
Cell Growth ◽  
Cell Lines ◽  
Genomic Alteration ◽  
Rt Pcr ◽  
Growth And Survival ◽  
Healthy Donors ◽  
Cell Growth And Survival

Abstract Background. Several TNF family members (CD40L and BAFF/BLYS) have been implicated in Waldenstrom’s Macroglobulinemia (WM) cell growth and survival. More recently, abnormalities in the APRIL-TACI pathway have been demonstrated by us in WM cells (Hunter, ASH2006, #228). TRAFs (TNFR-associated factor) are a family of adaptor proteins that mediate signal transduction from multiple members of the TNF receptor superfamily. In particular, TRAFs facilitate pro-apoptotic signaling from the TACI receptor, and TRAF2 is of importance among the TRAF adapter proteins since this protein is required for TNF-alpha-mediated activation of SAPK/JNK MAPK known to be involved in drug-induced death of tumor B cells. We therefore examined the role of TRAF2 in WM growth and survival. Method. We investigated TRAF2, 3 and 5 gene expression in WM patient bone marrow (BM) CD19+ cells and cell lines (BCWM.1, WSU-WM) and compared their expression to BM CD19+ cells from healthy donors. Expression of human TRAF transcripts were determined using real time quantitative RT-PCR (qPCR) based on TaqMan fluorescence methodology. To evaluate the role of TRAF2, a knockdown model was prepared in BL2126 B-cells and BCWM.1 WM cells using electroporation, with resulted ≥50% knockdown efficiency using RT-PCR and immunoblotting. Results. We found that TRAF3 and 5 gene expression was higher in WM versus healthy donors, while TRAF2 expression was lower in 8/13 (60%) patients, using qPCR. TRAFs gene expression did not correlate with tumor burden or WM prognostic markers. We next sought to understand the biological sequelae of TRAF2 deficiency in BL2126 and BCWM.1 cells and found that TRAF2 knockdown induced increased survival at 72 hours in both cell lines. We next studied sequence analysis of 20 WM patients CD19+ BM cells to determine whether there was a TRAF2 genomic alteration, and found heterozygous early termination mutation in exon 5 in 1 (5%) patient. Conclusion. Our data demonstrate that TRAF2 is a commonly dysregulated TNF family adapter protein in patients with WM, with important consequences in WM cell growth and survival.

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.

Metaherin Contributes To The Pathogenesis Of Chronic Lymohcytic Leukemia

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 4130-4130
Author(s):  
Peipei Li ◽  
Xin Wang ◽  
Chen Na ◽  
Lili Feng ◽  
Xueling Ge ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Flow Cytometry ◽  
B Cells ◽  
Signaling Pathway ◽  
Peripheral Blood ◽  
Wnt Signaling Pathway ◽  
Beta Catenin ◽  
Proliferation And Apoptosis ◽  
Normal Controls

Abstract Introduction Dysregulation of proliferation and apoptosis is associated the pathogenesis of CLL. More recently, Metadherin (MTDH) involved in aberrant proliferation, survival, and increased migration, invasiveness, and metastasis of tumor cells, has been demonstrated as a potential crucial mediator of various types of huamn malignancies. MTDH promotes tumor progression by modulating multiple oncogenic signaling pathways (NF-kB, PI3K/Akt and Wnt/beta-catenin). However, there is no report about the role of MTDH in CLL. Since Wnt signaling pathway had been proven to be unusual activated in CLL, the objective of this study was to investigate the role of MTDH in CLL and the relationship between MTDH and Wnt/beta-catenin signaling pathway. Methods Peripheral blood mononuclear cells (PBMCs) came from samples of 31 CLL patients. The characteristics of CLL patients were shown in Table 1. CD19+B cells were selected from peripheral blood of age-matched heathy donor, cord blood, bone marrow and tonsil of normal controls using CD19+ magnetic selection kits and detected the purity with anti-CD19-PE antibody by flow cytometry. Qantitative PCR and Western blot were used to detect the expression of mRNA and protein for MTDH, and the key functional components of Wnt/beta-catenin signaling pathway (beta-catenin and LEF-1). We also measured MTDH level in B cells by flow cytometry after intracellular staining. CLL cell line(MEC-1) were infected by lentivirus to interfer MTDH and the infection efficiencies were determined by fluorescence microscope and flow cytometry. Both primary CLL cells and MEC-1 were exposed to 10ug/ml goat F(ab`)2 anti-human IgM for 48hours to mimic activation of BCR. The proliferation and apoptosis of these cells were evaluated by CCK-8 method and Annexin V kits. Results mRNA of MTDH in PBMCs of 31 CLL patients were overexpression compared with CD19+ B cells coming from 15 age-matched healthy donors (Figure 1A). 27 out of 31 CLL samples were detected MTDH expression in protein level but none in normal controls (Figure 1B). The expression of MTDH was associated with Rai staging of CLL. There were no MTDH detection in CD19+ B cells collected from bone marrow, peripheral blood, tonsil and cord blood, which stand for precursor, mature, germinal center, and lineage B cells, respectively. The transfection efficiency of MEC-1 cells by interfering MTDH expression with Lentivirus was shown in Figure 1C. The level of MTDH knockdown was accompanied with LEF-1 downregulation (Figure 1D, 1E), as well as the downregulation of c-myc and cyclinD1 expression (Figure 1F). siRNA targeting MTDH treatment in MEC-1 decreased the proliferation and increased the apoptosis(Figure 2A, 2B). We further observed that the proliferation and MTDH expression both in CLL cells and MEC-1 were upregulation after stimulation of anti-human IgM (Figure 2C, 2D, 2E). This effect in the proliferation was blocked by MTDH inteference (Figure 2F). Conclusions Our results demonstrated that MTDH is aberrant expression in B cells of CLL patients and correlated with clinical staging of CLL. MTDH was not expression in any subsets of normal B cells. MTDH may exert a preservative role through activation of Wnt signaling pathway. The CLL cell proliferation activation by BCR signaling pathway may be inhibited by MTDH interference. Our findings indicated that MTDH may be a potential therapeutic target of CLL. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Impaired early B cell tolerance in patients with rheumatoid arthritis

2005 ◽  
Vol 201 (10) ◽  
pp. 1659-1667 ◽  
Author(s):  
Jonathan Samuels ◽  
Yen-Shing Ng ◽  
Claire Coupillaud ◽  
Daniel Paget ◽  
Eric Meffre
Keyword(s):  
Rheumatoid Arthritis ◽  
B Cells ◽  
B Cell ◽  
Cell Tolerance ◽  
B Cell Tolerance ◽  
Autoantibody Production ◽  
Autoreactive B Cells ◽  
Healthy Donors ◽  
Polyreactive Antibodies

Autoantibody production is a characteristic of most autoimmune diseases including rheumatoid arthritis (RA). The role of these autoantibodies in the pathogenesis of RA remains elusive, but they appear in the serum many years before the onset of clinical disease suggesting an early break in B cell tolerance. The stage of B cell development at which B cell tolerance is broken in RA remains unknown. We previously established in healthy donors that most polyreactive developing B cells are silenced in the bone marrow, and additional autoreactive B cells are removed in the periphery. B cell tolerance in untreated active RA patients was analyzed by testing the specificity of recombinant antibodies cloned from single B cells. We find that autoreactive B cells fail to be removed in all six RA patients and represent 35–52% of the mature naive B cell compartment compared with 20% in healthy donors. In some patients, RA B cells express an increased proportion of polyreactive antibodies that can recognize immunoglobulins and cyclic citrullinated peptides, suggesting early defects in central B cell tolerance. Thus, RA patients exhibit defective B cell tolerance checkpoints that may favor the development of autoimmunity.

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