scholarly journals Intrathecal B-cell activation in LGI1 antibody encephalitis

2020 ◽  
Vol 7 (2) ◽  
pp. e669 ◽  
Author(s):  
Klaus Lehmann-Horn ◽  
Sarosh R. Irani ◽  
Shengzhi Wang ◽  
Arumugam Palanichamy ◽  
Sarah Jahn ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Cell Activation ◽  
Mononuclear Cells ◽  
Cell Activity ◽  
Oligoclonal Bands ◽  
B Cell Activation ◽  
Cell Repertoire ◽  
Antibody Titers ◽  
B Cell Subsets

ObjectiveTo study intrathecal B-cell activity in leucine-rich, glioma-inactivated 1 (LGI1) antibody encephalitis. In patients with LGI1 antibodies, the lack of CSF lymphocytosis or oligoclonal bands and serum-predominant LGI1 antibodies suggests a peripherally initiated immune response. However, it is unknown whether B cells within the CNS contribute to the ongoing pathogenesis of LGI1 antibody encephalitis.MethodsPaired CSF and peripheral blood (PB) mononuclear cells were collected from 6 patients with LGI1 antibody encephalitis and 2 patients with other neurologic diseases. Deep B-cell immune repertoire sequencing was performed on immunoglobulin heavy chain transcripts from CSF B cells and sorted PB B-cell subsets. In addition, LGI1 antibody levels were determined in CSF and PB.ResultsSerum LGI1 antibody titers were on average 127-fold higher than CSF LGI1 antibody titers. Yet, deep B-cell repertoire analysis demonstrated a restricted CSF repertoire with frequent extensive clusters of clonally related B cells connected to mature PB B cells. These clusters showed intensive mutational activity of CSF B cells, providing strong evidence for an independent CNS-based antigen-driven response in patients with LGI1 antibody encephalitis but not in controls.ConclusionsOur results demonstrate that intrathecal immunoglobulin repertoire expansion is a feature of LGI1 antibody encephalitis and suggests a need for CNS-penetrant therapies.

scholarly journals PTIP chromatin regulator controls development and activation of B cell subsets to license humoral immunity in mice

2017 ◽  
Vol 114 (44) ◽  
pp. E9328-E9337 ◽  
Author(s):  
Dan Su ◽  
Stijn Vanhee ◽  
Rebeca Soria ◽  
Elin Jaensson Gyllenbäck ◽  
Linda M. Starnes ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Humoral Immunity ◽  
Cell Activation ◽  
Cell Receptor ◽  
B Cell Receptor ◽  
Transactivation Domain ◽  
B Cell Activation ◽  
Chromatin Regulator ◽  
B Cell Subsets

B cell receptor signaling and downstream NF-κB activity are crucial for the maturation and functionality of all major B cell subsets, yet the molecular players in these signaling events are not fully understood. Here we use several genetically modified mouse models to demonstrate that expression of the multifunctional BRCT (BRCA1 C-terminal) domain-containing PTIP (Pax transactivation domain-interacting protein) chromatin regulator is controlled by B cell activation and potentiates steady-state and postimmune antibody production in vivo. By examining the effects of PTIP deficiency in mice at various ages during ontogeny, we demonstrate that PTIP promotes bone marrow B cell development as well as the neonatal establishment and subsequent long-term maintenance of self-reactive B-1 B cells. Furthermore, we find that PTIP is required for B cell receptor- and T:B interaction-induced proliferation, differentiation of follicular B cells during germinal center formation, and normal signaling through the classical NF-κB pathway. Together with the previously identified role for PTIP in promoting sterile transcription at the Igh locus, the present results establish PTIP as a licensing factor for humoral immunity that acts at several junctures of B lineage maturation and effector cell differentiation by controlling B cell activation.

Activation and Proliferation of B Cell Chronic Lymphocytic Leukaemia (B-CLL) Cells through Anti-CD180, Anti-CD40 and IL-4.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 4775-4775
Author(s):  
Nino Porakishvili ◽  
Maria Manoussaka ◽  
Nino Kulikova ◽  
James Walton ◽  
Amit Nathwani ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Normal Control ◽  
Cell Activation ◽  
Mononuclear Cells ◽  
Leukemic Cells ◽  
B Cell Activation ◽  
Cell Cycle Protein ◽  
Cd40 Ligation ◽  
Ki 67

Abstract Introduction: We have previously shown that Toll-like receptor RP105 (CD180) is heterogeneously expressed on B-CLL cells and that the ligation of CD180 by monoclonal antibodies (mAb) on CD180+ B-CLL cells resulted in delineation of responder and non-responder B-CLL clones [1]. In this study we have examined the role of IL-4 together with CD180 and CD40 as activation signals. Methods: Blood mononuclear cells were separated from 7 responder B-CLL patients with both mutated and unmutated Ig Vh genes and 11 controls and were cultured for 72 hours in optimum concentrations of anti-CD180 (G28-8) or anti-CD40 mAb or both in presence and absence of 15 ng/ml of IL-4. CD19+ B cells were stained with mAb to the activation marker CD86 or cell cycle protein Ki-67, measured by flow cytometry and expressed as Mean Fluorescence Intensity (MFI) or % of Ki-67+ cells. Results: B-CLL cells and normal control B cells responded to CD180-ligation by activation and proliferation (Table). Higher levels of CD86 and Ki67 were detected when both anti CD40 mAb and anti CD180 mAb were added (p<0.05) compared with either alone. IL4 alone induced both activation and proliferation of control cells and this was even higher with the leukemic cells (p<0.01) confirming that IL-4 also provides a strong survival/activatory stimulus for B-CLL cells. Addition of IL-4 had no significant enhancing effect on normal B-cells stimulated with both anti-CD180 and anti-CD40, although IL-4 synergised with anti-CD40 in B cell activation (p=0.026) and with CD180 in B cell proliferation (p=0.044). Conclusion: CD180 had an additive effect with CD40 ligation in activation and proliferation of both B-CLL cells and normal control B cells. IL-4 provides a strong additional stimulus for B-CLL cells. CD86 and Ki-67 expression by CD19+ cells CD86 Ki67 B-CLL Control B-CLL control Spontaneous −IL-4 7.2±4.1 4.0±1.0 8.1±2.7 17.4±2.3 +IL-4 22.4±11.8 11.2±4.2 17.0±12.8 23.6±14.8 CD180 −IL-4 14.7±5.8 26.9±13.0 17.1±10.9 28.1±12.0 +IL-4 35.4±14.5 30.0±14.6 26.9±25.6 48.3±9.7 CD40 −IL-4 19.4±8.8 14.8±5.2 14.9±9.7 34.0±5.1 +IL-4 286±145.5 44.0±19.4 52.7±22.8 41.0±19.8 CD180+CD40 −IL-4 32.5±12.6 97.0±26.2 28.0±10.4 65.5±26.6 +IL-4 299±163.2 63.5±27.4 49.3±14.6 55.5±26.4

scholarly journals Hantavirus infection-induced B cell activation elevates free light chains levels in circulation

2021 ◽  
Vol 17 (8) ◽  
pp. e1009843
Author(s):  
Jussi Hepojoki ◽  
Luz E. Cabrera ◽  
Satu Hepojoki ◽  
Carla Bellomo ◽  
Lauri Kareinen ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Cell Activation ◽  
Mononuclear Cells ◽  
Cell Clone ◽  
Light Chains ◽  
Hantavirus Infection ◽  
Puumala Virus ◽  
B Cell Activation ◽  
Free Light Chains

In humans, orthohantaviruses can cause hemorrhagic fever with renal syndrome (HFRS) or hantavirus pulmonary syndrome (HPS). An earlier study reported that acute Andes virus HPS caused a massive and transient elevation in the number of circulating plasmablasts with specificity towards both viral and host antigens suggestive of polyclonal B cell activation. Immunoglobulins (Igs), produced by different B cell populations, comprise heavy and light chains; however, a certain amount of free light chains (FLCs) is constantly present in serum. Upregulation of FLCs, especially clonal species, associates with renal pathogenesis by fibril or deposit formations affecting the glomeruli, induction of epithelial cell disorders, or cast formation in the tubular network. We report that acute orthohantavirus infection increases the level of Ig FLCs in serum of both HFRS and HPS patients, and that the increase correlates with the severity of acute kidney injury in HFRS. The fact that the kappa to lambda FLC ratio in the sera of HFRS and HPS patients remained within the normal range suggests polyclonal B cell activation rather than proliferation of a single B cell clone. HFRS patients demonstrated increased urinary excretion of FLCs, and we found plasma cell infiltration in archival patient kidney biopsies that we speculate to contribute to the observed FLC excreta. Analysis of hospitalized HFRS patients’ peripheral blood mononuclear cells showed elevated plasmablast levels, a fraction of which stained positive for Puumala virus antigen. Furthermore, B cells isolated from healthy donors were susceptible to Puumala virus in vitro, and the virus infection induced increased production of Igs and FLCs. The findings propose that hantaviruses directly activate B cells, and that the ensuing intense production of polyclonal Igs and FLCs may contribute to acute hantavirus infection-associated pathological findings.

scholarly journals Rheumatoid Factors Induce Signaling from B Cells, Leading to Epstein-Barr Virus and B-Cell Activation

2004 ◽  
Vol 78 (18) ◽  
pp. 9918-9923 ◽  
Author(s):  
Lixin Yang ◽  
Masayuki Hakoda ◽  
Kazuya Iwabuchi ◽  
Tsuyoshi Takeda ◽  
Takao Koike ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Epstein Barr Virus ◽  
Cell Activation ◽  
Mononuclear Cells ◽  
Rheumatoid Factors ◽  
B Cell Activation ◽  
Barr Virus ◽  
Membrane Bound ◽  
Epstein Barr

ABSTRACT B-cell antigen receptor signaling is initiated upon binding of the antigen to membrane-bound immunoblobulin (Ig), and the anti-Ig antibody (Ab) mimics this signaling. In B cells latently infected with Epstein-Barr virus (EBV), the same signals induce virus activation. We examine here whether rheumatoid factors (RFs), autoantibodies directed against the Fc portion of IgG, induce EBV and B-cell activation. As a source of RFs, RF-producing lymphoblastoid cell line (LCL) clones were isolated from peripheral blood mononuclear cells (PBMC) and synovial cells from patients with rheumatoid arthritis (RA) by EBV transformation. Burkitt's lymphoma-derived Akata cells, which are highly responsive to EBV activation by anti-Ig Abs, were used for the assay of EBV activation. Akata cells expressed IgG3 as membrane-bound Ig. RFs from a synovium-derived LCL were directed to IgG3 and induced EBV activation in 16 to 18% of Akata cells, whereas RFs from another synovium-derived LCL were directed to IgG1 and did not induce EBV activation. Pretreatment of RFs with the purified Fc fragment of human IgG completely abolished EBV activation. Furthermore, B-cell activation was assessed by incorporation of [3H]thymidine. RFs from synovium-derived LCLs efficiently induced B-cell activation, and the addition of CD40 ligand had a synergistic effect. On the other hand, RFs from PBMC-derived LCLs were polyreactive, had a lower affinity to IgG, and did not induce EBV and B-cell activation. The present findings imply a possible role for RFs as EBV and B-cell activators.

STAT3 phosphorylation mediates the stimulatory effects of interferon alpha on B cell differentiation and activation in SLE

Rheumatology ◽  
2019 ◽  
Author(s):  
Aurélie De Groof ◽  
Julie Ducreux ◽  
Floor Aleva ◽  
Andrew J Long ◽  
Alina Ferster ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
B Cells ◽  
B Cell ◽  
Cell Activation ◽  
Mononuclear Cells ◽  
Type I ◽  
B Cell Differentiation ◽  
B Cell Activation ◽  
Loss Of Function ◽  
Stat3 Phosphorylation

Abstract Objective Type I IFNs play a well-known role in the pathogenesis of SLE, through activation of CD4 T and antigen-presenting cells. Here, we investigated the effects of IFN alpha (IFNα) on SLE B cell activation and differentiation. Methods Peripheral blood mononuclear cells (PBMCs) and purified total or naïve B cells were obtained from healthy controls and SLE patients. The effects of IFNα on B cell differentiation were studied by flow cytometry. The role of STAT3 in B cell responses to IFNα was studied using pharmacological inhibitors and PBMCs from STAT3-deficient individuals. Results Incubation of normal PBMCs with IFNα induces a B cell differentiation pattern as observed spontaneously in SLE PBMCs. IFNα displays direct stimulatory effects on purified naïve B cells from healthy individuals, as evidenced by a significant induction of cell surface CD38 and CD95 in the presence of the cytokine. In purified naïve B cells, IFNα also induces STAT3 phosphorylation. IFNα-induced naïve B cell differentiation in total PBMCs is significantly inhibited in the presence of STAT3 inhibitors, or in PBMCs from individuals with STAT3 loss of function mutations. Spontaneous levels of STAT3, but not STAT1, phosphorylation are significantly higher in total B cells from SLE patients compared with controls. Pharmacological STAT3 inhibition in SLE PBMCs inhibits naïve B cell activation and differentiation. Conclusion IFNα displays direct stimulatory effects on B cell differentiation and activation in SLE. STAT3 phosphorylation mediates the effects of IFNα stimulation in naïve B cells, an observation that opens new therapeutic perspectives in SLE.

scholarly journals Carrier-directed anti-hapten responses by b-cell subsets

1977 ◽  
Vol 146 (1) ◽  
pp. 1-10 ◽  
Author(s):  
GK Lewis ◽  
JW Goodman
Keyword(s):  
B Cells ◽  
B Cell ◽  
Cell Activation ◽  
Burst Size ◽  
Cell Subset ◽  
B Cell Activation ◽  
Cell Subpopulations ◽  
Activation Pathways ◽  
B Cell Subsets

The capacity of the trinitrophenyl (TNP) haptenic group, coupled to a series of chemically dissimilar carriers, to cross-stimulate putative T- dependent and T-independent murine B-cell subpepulations was determined by using an in vitro limiting dilution technique to generate primary IgM responses. It was found that TNP-Ficoll and TNP-dextran, two T- independent antigens with little or no polyclonal mitogenicity, stimulate the same population of anti-TNP precursors, which is distinct from the precursor population activated by TNP-bacterial lipopolysaccharide (LPS), a T-independent polyclonal mitogen, or TNP-horse erythrocytes (HRBC), a T-dependent antigen. On the other hand, TNP-LPS and TNP-HRBC activate the same precursor population, indicating that LPS can substitute for the T- cell signal in T-dependent B-cell responses, whereas nonmitogenic T- independent antigens cannot. However, the cumulative evidence from this and other laboratories strongly indicates that LPS and T-dependent antigens activate B cells by different mechanisms. Of particular interest, LPS is incapable of activating B cells responsive to weakly- or nonmitogenic T-independent antigens. Based on clonal burst size, T-dependent antigens are capable of inducing greater antigen-specific B-cell proliferation than T-independent antigens. However, TNP conjugates of Ficoll and dextran, which are relatively poor inducers of polyclonal B-cell activation, induced larger anti-TNP clones than did TNP-LPS, a strong polyclonal mitogen. The findings reinforce the evidence favoring existence of multiple B- cell subpopulations with distinctive activation pathways. They also strengthen the proposition that a given B-cell subset can be activated by more than one mechanism.

scholarly journals Systemic autoimmune disease arises from polyclonal B cell activation.

1987 ◽  
Vol 165 (6) ◽  
pp. 1755-1760 ◽  
Author(s):  
D M Klinman ◽  
A D Steinberg
Keyword(s):  
B Cells ◽  
B Cell ◽  
Cell Activation ◽  
Systemic Autoimmune Disease ◽  
Single Cell Level ◽  
B Cell Activation ◽  
Cell Level ◽  
Cell Repertoire ◽  
Systemic Autoimmune Diseases ◽  
B Cell Repertoire

The number of B cells producing antibodies reactive with any of seven autoantigens or two conventional antigens was compared at the single-cell level to the total number of Ig-secreting B cells present in the spleens of NZB, MRL lpr/lpr, and BXSB autoimmune mice. The proportion of lymphocytes producing antibodies of each specificity, expressed as a percentage of the total B cell repertoire, was virtually identical among autoimmune and congenic nonautoimmune animals. Furthermore, B cells and serum antibodies reactive with conventional antigens increased commensurately with those reactive with autoantigens. These results indicate that systemic autoimmune diseases arise from polyclonal B cell activation.

scholarly journals Osteopontin and malaria: no direct effect on parasite growth, but correlation with P. falciparum-specific B cells and BAFF in a malaria endemic area

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Susanne E Mortazavi ◽  
Allan Lugaajju ◽  
Mark Kaddumukasa ◽  
Muyideen Kolapo Tijani ◽  
Fred Kironde ◽  
...  
Keyword(s):  
Immune Response ◽  
B Cells ◽  
B Cell ◽  
Direct Effect ◽  
Cell Activation ◽  
Cell Immune Response ◽  
Natural Immunity ◽  
B Cell Activation ◽  
B Cell Subsets

Abstract Background The dysregulation of B cell activation is prevalent during naturally acquired immunity against malaria. Osteopontin (OPN), a protein produced by various cells including B cells, is a phosphorylated glycoprotein that participates in immune regulation and has been suggested to be involved in the immune response against malaria. Here we studied the longitudinal concentrations of OPN in infants and their mothers living in Uganda, and how OPN concentrations correlated with B cell subsets specific for P. falciparum and B cell activating factor (BAFF). We also investigated the direct effect of OPN on P. falciparum in vitro. Results The OPN concentration was higher in the infants compared to the mothers, and OPN concentration in infants decreased from birth until 9 months. OPN concentration in infants during 9 months were independent of OPN concentrations in corresponding mothers. OPN concentrations in infants were inversely correlated with total atypical memory B cells (MBCs) as well as P. falciparum-specific atypical MBCs. There was a positive correlation between OPN and BAFF concentrations in both mothers and infants. When OPN was added to P. falciparum cultured in vitro, parasitemia was unaffected regardless of OPN concentration. Conclusions The concentrations of OPN in infants were higher and independent of the OPN concentrations in corresponding mothers. In vitro, OPN does not have a direct effect on P. falciparum growth. Our correlation analysis results suggest that OPN could have a role in the B cell immune response and acquisition of natural immunity against malaria.

scholarly journals Beyond autoantibodies: Biological roles of human autoreactive B cells in rheumatoid arthritis revealed by whole transcriptome profiling

2017 ◽  
Author(s):  
Ankit Mahendra ◽  
Xingyu Yang ◽  
Shaza Abnouf ◽  
Daechan Park ◽  
Sanam Soomro ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
B Cells ◽  
B Cell ◽  
Cell Activation ◽  
Transcriptome Profiling ◽  
B Cell Activation ◽  
Autoreactive B Cells ◽  
Downstream Signaling ◽  
Approved Drugs ◽  
B Cell Subsets

AbstractAlthough the contribution of B-cell derived autoreactive antibodies to rheumatoid arthritis (RA) has been studied extensively, the autoantibody-independent roles of B cells in the progression of the disease is not well-defined. Here we present the first comprehensive transcriptome profile of human autoreactive B cells in an autoimmune disease by performing RNA-sequencing of citrulline-specific B cells from RA patients. In order to facilitate a comprehensive understanding of the profile of these citrulline-specific (RA-CCPPOS) B cells, we performed comparative analyses to both citrulline-negative (RA-CCPNEG) B cells from the same donors, and identified 431 differentially expressed genes (DEGs); and hemagglutinin-specific (HA) B cells from healthy individuals and identified 1658 DEGs. Three-way comparisons of these B cell populations demonstrated that RA-CCPPOS B cells, in comparison to the RA-CCPNEG B cells, demonstrate a potential role in protein citrullination and inflammation; RA-CCPPOS B cells in comparison to HA-specific B cells demonstrate RA-specific signatures like the expression of pro-inflammatory cytokines, chemokines, costimulatory molecules and B-cell activation cascades; and all B cells from RA patients demonstrated a significant impact of the multitude of TNF signaling pathways. Furthermore, transcription factor profiling suggested that cyclic AMP (cAMP) related pathways and downstream signaling molecules are selectively enriched in RA-CCPPOS cells in comparison to the other two B cell subsets. We advanced the understanding of the citrulline reactive B cells in RA pathophysiology by documenting and validating two novel observations in independent cohorts of patients: (1) the expression of IL15Rα is restricted to citrulline-specific cells within RA patients and the concentration of soluble IL15Rα is elevated in the sera of RA patients, (2) B cells from RA patients are capable of producing epidermal growth factor ligand, amphiregulin (AREG) which in turn has a direct impact on the mechanistic effectors of RA, osteoclasts and fibroblastlike synoviocytes (FLS). Overall, our comprehensive dataset identifies several existing FDA-approved drugs that can potentially be repurposed for RA and can serve as a foundation for studying the multi-faceted roles of B cells in other autoimmune diseases.

scholarly journals CD21lo/−CD27−IgM− Double-Negative B Cells Accumulate in the Joints of Patients With Antinuclear Antibody-Positive Juvenile Idiopathic Arthritis

2021 ◽  
Vol 9 ◽  
Author(s):  
Johannes Dirks ◽  
Jonas Fischer ◽  
Gabriele Haase ◽  
Annette Holl-Wieden ◽  
Christine Hofmann ◽  
...  
Keyword(s):  
Juvenile Idiopathic Arthritis ◽  
B Cells ◽  
B Cell ◽  
Cell Activation ◽  
Cross Sectional Study ◽  
Double Negative ◽  
B Cell Differentiation ◽  
B Cell Activation ◽  
Cross Sectional ◽  
B Cell Subsets

Juvenile idiopathic arthritis (JIA) encompasses a heterogeneous group of diseases. The appearance of antinuclear antibodies (ANAs) in almost half of the patients suggests B cell dysregulation as a distinct pathomechanism in these patients. Additionally, ANAs were considered potential biomarkers encompassing a clinically homogenous subgroup of JIA patients. However, in ANA+ JIA patients, the site of dysregulated B cell activation as well as the B cell subsets involved in this process is still unknown. Hence, in this cross-sectional study, we aimed in an explorative approach at characterizing potential divergences in B cell differentiation in ANA+ JIA patients by assessing the distribution of peripheral blood (PB) and synovial fluid (SF) B cell subpopulations using flow cytometry. The frequency of transitional as well as switched-memory B cells was higher in PB of JIA patients than in healthy controls. There were no differences in the distribution of B cell subsets between ANA- and ANA+ patients in PB. However, the composition of SF B cells was different between ANA- and ANA+ patients with increased frequencies of CD21lo/−CD27−IgM− “double negative” (DN) B cells in the latter. DN B cells might be a characteristic subset expanding in the joints of ANA+ JIA patients and are potentially involved in the antinuclear immune response in these patients. The results of our explorative study might foster further research dissecting the pathogenesis of ANA+ JIA patients.

Sign in / Sign up

Export Citation Format

Share Document