scholarly journals An intrinsic B cell defect is required for the production of autoantibodies in the lpr model of murine systemic autoimmunity.

1991 ◽  
Vol 173 (6) ◽  
pp. 1441-1449 ◽  
Author(s):  
E S Sobel ◽  
T Katagiri ◽  
K Katagiri ◽  
S C Morris ◽  
P L Cohen ◽  
...  
Keyword(s):  
Bone Marrow ◽  
T Cell ◽  
B Cells ◽  
Lupus Erythematosus ◽  
Immunofluorescence Assay ◽  
Total Serum ◽  
Enzyme Linked Immunosorbent Assay ◽  
Cell Phenotype ◽  
Autoantibody Production ◽  
Systemic Autoimmunity

Mice homozygous for the gene lpr develop marked lymphadenopathy and a spectrum of autoantibodies closely resembling that of human systemic lupus erythematosus. The unusual T cell phenotype of the expanded lymphocyte population and the T-dependence of several antibodies in this strain have suggested that primary T cell abnormalities underlie the autoimmune syndrome. Using double chimeras, we now show that expression of the lpr gene in B cells is absolutely necessary for autoantibody production. Combinations of anti-Thy 1.2 + C' treated bone marrow from congenic strains of C57BL/6 mice, differing only at the immunoglobulin heavy chain (Igh) and lpr loci, were transferred into lethally irradiated B6/lpr mice. Double chimerism was documented by allotype-specific surface IgD and IgM immunofluorescence assay of peripheral blood and by allotype-specific enzyme-linked immunosorbent assay for total IgM in serum. Despite the presence of both +/+ and lpr B cells, IgM and IgG2a anti-chromatin as well as IgM anti-IgG were entirely the products of lpr B cells. Total serum IgG2a and IgG1 were also dominated by the lpr phenotype but not to the same extent. A similar experiment using B6/lpr-Igha recipients confirmed these findings. Additional experiments in which B6/lpr recipients were infused with ratios of donor bone marrow favoring B6.C20 +/+ over B6/lpr showed that even though +/+ B cells were overrepresented, autoantibodies were only of the lpr allotype. In addition, in the presence of lpr B cells, normal B cells showed little response to an exogenous, T cell-dependent antigen. The data thus indicate that lpr B cells manifest an intrinsic abnormality which is essential for autoantibody production in the lpr model.

scholarly journals The immunoregulatory effects of merocyanine 540 on in vitro human T- and B-lymphocyte functions

Blood ◽  
1991 ◽  
Vol 77 (12) ◽  
pp. 2701-2706
Author(s):  
LG Lum ◽  
M Yamagami ◽  
BR Giddings ◽  
I Joshi ◽  
SL Schober ◽  
...  
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
T Cell ◽  
B Cells ◽  
Light Exposure ◽  
Autologous Bone Marrow Transplantation ◽  
Enzyme Linked Immunosorbent Assay ◽  
Con A ◽  
Merocyanine 540 ◽  
Ig Synthesis

Merocyanine 540 (MC 540) is a photoactive dye used to purge bone marrow of tumor cells in autologous bone marrow transplantation. The effects of MC 540 on the lymphoid components in the marrow are unknown. This study evaluates the treatment of lymphocytes by MC 540 (15 micrograms/mL) and light (70 W/m2) on: (1) phytohemagglutinin and Con A- induced proliferation; (2) allogeneic mixed lymphocyte cultures (MLC); (3) the regulation of Ig synthesis by T cells; and (4) the ability of B cells to produce polyclonal Igs as measured by an enzyme-linked immunosorbent assay-plaque assay. The results show that MC 540 and light treatment reduced Con A-stimulated T-cell proliferation greater than 50% after 30 minutes and greater than 80% after 60 minutes of MC 540-sensitized photoirradiation. Ninety minutes of MC 540 and light exposure (designated treatment) inhibited MLC greater than 90%. In polyclonal Ig synthesis, T-cell helper activity could be abrogated by 90 minutes of treatment in cocultures containing untreated B cells. Purified B cells treated for 90 minutes cocultured with normal T cells did not produce Ig. Treatment of B cells completely inhibited Epstein- Barr virus-stimulated Ig synthesis. These data show that T- and B-cell immunity is suppressed by the MC 540-sensitized photoirradiation. Treatment of bone marrow with MC 540 and light may have profound effects on immune reconstitution in autologous marrow graft recipients. More provocative is the fact that the same immunomodulatory effects may be applicable to partially mismatched marrow transplant situations as a means of reducing graft-versus-host reactions.

scholarly journals OP0026 IGF1R DEPENDENT CELL INTERACTION AND REGULATION OF AUTOANTIBODY PRODUCTION IN RHEUMATOID ARTHRITIS

2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 14.2-14
Author(s):  
S. Erdogan ◽  
M. Erlandsson ◽  
N. Oparina ◽  
C. Lundquist ◽  
C. Wasen ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
T Cell ◽  
B Cells ◽  
Immune Cell ◽  
Cell Communication ◽  
Type Ii Collagen ◽  
Cell Phenotype ◽  
Strong Positive Correlation ◽  
Autoantibody Production ◽  
Antigen Presenting

Background:The insulin-like growth factor 1 receptor (IGF1R) signalling mediates numerous developmental processes acting through downstream adaptor molecules IRS1/2, which activate Akt and inhibit the family of forkhead box class O (FoxO). Inhibition of IGF1R signalling alleviates rheumatoid arthritis (RA) (Erlandsson et al., 2017), however, the role of IGF1R signalling in the regulation of immune function is poorly understood.Objectives:To investigate the link between IGF1R signalling and antigen presentation in experimental arthritis.Methods:Arthritis was induced by immunising Balb/c mice with methylated bovine serum albumin (mBSA, n=18) and DBA/1 mice with type II collagen (CII, n=18). The mice were treated with a synthetic IGF1R inhibitor NT157 or with short hairpin RNA targeting IGF1R (shIGF1R) from the day prior to immunisation. Controls were treated with cyclodextrine vehicle/ non-targeting (nt)RNA, respectively. Flow cytometry was used for spleen cell phenotype. Antibody levels were measured by ELISA. Immunohistochemistry (IHC) of spleen was performed for assessment of marginal zone (MZ) and location of pS612IRS1+ and pS256FoxO1+ cells. IHC images were acquired by fluorescent confocal microscopy, and analysed using ZEN2009 and Cell Profiler soft ware.Results:The inhibition of IGF1R resulted in an 80% increase in MZ area in NT157-treated mice compared to controls (p=0.0001). This was supported by a significant increase of CD21+ (p=0.034) and CD23+ cell populations (p=0.00059), both among the CD19+ B cells and antigen-presenting MHCII+CD19- cells, implying that IGF1R expression regulates the populations of MZ and follicular cells. Additionally, there was a strong positive correlation between the decrease of IGF1R+ and ICOSL+ population on CD21+ cells (r=0.70, p=0.0071), which retained them in the MZ and prolonged communication with macrophages. Insufficient feedback from ICOSL- B cells limited expression of CXCR5 on CD4 cells. The IHC analysis displayed that, IGF1R inhibition led to abundance of inactivate pS612IRS1+ and pS256FoxO1+ cells within the MZ, compared with controls (p=0.0002). Alongside the increase of IgM+ B cell population (p=0.0022), we observed significant increase in number of antigen-presenting F4/80+ cells (p=0.043) and MARCO expression (p=0.043) after IGF1R intervention. Finally, the NT157- treated mice displayed a significant pleiotropic increase in IgM autoantibody production, with anti-CCP IgM (p=0.027), RF-IgM (p=0.0085), anti-DNA IgM (p=0.066) and in total IgM (p=0.027) levels, which correlated positively with pS256FoxO1+ cells (r=0.51, p=0.03). Levels of IgG were not changed.Conclusion:We show that IGF1R signalling is important for immune cell communication after antigen challenge. IGF1R controls ICOSL dependent trafficking of B cells through the MZ and facilitates interaction with T cells. Retention of B cells in the MZ tips the balance from T cell to macrophage-dependent processes, which permits the formation of autoantibody producing B cells.References:[1]Erlandsson, M., et.al., 2017. IGF-1R signalling contributes to IL-6 production and T cell dependent inflammation in rheumatoid arthritis. Biochimica et Biophysica Acta (BBA) - Molecular Basis of Disease, 1863(9), pp.2158-2170.Disclosure of Interests:None declared

scholarly journals CXCR4+ Treg cells control serum IgM levels and natural IgM autoantibody production by B1 cells in the bone marrow

2021 ◽  
Author(s):  
Shlomo Elias ◽  
Rahul Sharma ◽  
Michael Schizas ◽  
Izabella Valdez ◽  
Sun-Mi Park ◽  
...  
Keyword(s):  
Bone Marrow ◽  
B Cells ◽  
Plasma Cells ◽  
Treg Cells ◽  
Total Serum ◽  
Dependent Manner ◽  
Autoantibody Production ◽  
Hematopoietic Stem ◽  
Control Serum ◽  
B1 Cells

Regulatory T (Treg) cells represent a specialized lineage of suppressive CD4+ T cells, whose functionality is critically dependent on their ability to migrate to, and dwell in the proximity of cells they control. Here we show that continuous expression of the chemokine receptor CXCR4 in Treg cells is required for their ability to accumulate in the bone marrow (BM). Induced CXCR4 ablation in Treg cells led to their rapid depletion and consequent increase in mature B cells, foremost B-1 subset, observed exclusively in the BM without detectable changes in plasma cells or hematopoietic stem cells or any signs of systemic or local immune activation elsewhere. Dysregulation of BM B-1 B cells was associated with a highly specific increase in IgM autoantibodies and the total serum IgM levels. Thus, Treg cells control autoreactive B-1 B cells in a CXCR4-dependent manner. These findings have significant implications for understanding of regulation of B cell autoreactivity and malignancies.

scholarly journals The immunoregulatory effects of merocyanine 540 on in vitro human T- and B-lymphocyte functions

Blood ◽  
1991 ◽  
Vol 77 (12) ◽  
pp. 2701-2706 ◽  
Author(s):  
LG Lum ◽  
M Yamagami ◽  
BR Giddings ◽  
I Joshi ◽  
SL Schober ◽  
...  
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
T Cell ◽  
B Cells ◽  
Light Exposure ◽  
Autologous Bone Marrow Transplantation ◽  
Enzyme Linked Immunosorbent Assay ◽  
Con A ◽  
Merocyanine 540 ◽  
Ig Synthesis

Abstract Merocyanine 540 (MC 540) is a photoactive dye used to purge bone marrow of tumor cells in autologous bone marrow transplantation. The effects of MC 540 on the lymphoid components in the marrow are unknown. This study evaluates the treatment of lymphocytes by MC 540 (15 micrograms/mL) and light (70 W/m2) on: (1) phytohemagglutinin and Con A- induced proliferation; (2) allogeneic mixed lymphocyte cultures (MLC); (3) the regulation of Ig synthesis by T cells; and (4) the ability of B cells to produce polyclonal Igs as measured by an enzyme-linked immunosorbent assay-plaque assay. The results show that MC 540 and light treatment reduced Con A-stimulated T-cell proliferation greater than 50% after 30 minutes and greater than 80% after 60 minutes of MC 540-sensitized photoirradiation. Ninety minutes of MC 540 and light exposure (designated treatment) inhibited MLC greater than 90%. In polyclonal Ig synthesis, T-cell helper activity could be abrogated by 90 minutes of treatment in cocultures containing untreated B cells. Purified B cells treated for 90 minutes cocultured with normal T cells did not produce Ig. Treatment of B cells completely inhibited Epstein- Barr virus-stimulated Ig synthesis. These data show that T- and B-cell immunity is suppressed by the MC 540-sensitized photoirradiation. Treatment of bone marrow with MC 540 and light may have profound effects on immune reconstitution in autologous marrow graft recipients. More provocative is the fact that the same immunomodulatory effects may be applicable to partially mismatched marrow transplant situations as a means of reducing graft-versus-host reactions.

scholarly journals Complement C4 Inhibits Systemic Autoimmunity through a Mechanism Independent of Complement Receptors Cr1 and Cr2

2000 ◽  
Vol 192 (9) ◽  
pp. 1339-1352 ◽  
Author(s):  
Zhibin Chen ◽  
Sergei B. Koralov ◽  
Garnett Kelsoe
Keyword(s):  
B Cells ◽  
Lupus Erythematosus ◽  
Complement Receptors ◽  
T And B Cells ◽  
Autoantibody Production ◽  
Systemic Autoimmunity ◽  
C4 Deficiency ◽  
Humoral Responses ◽  
The Complement System ◽  
Normal Controls

The complement system enhances antibody responses to T-dependent antigens, but paradoxically, deficiencies in C1 and C4 are strongly linked to autoantibody production in humans. In mice, disruption of the C1qa gene also results in spontaneous autoimmunity. Moreover, deficiencies in C4 or complement receptors 1 and 2 (CR1/CR2) lead to reduced selection against autoreactive B cells and impaired humoral responses. These observations suggest that C1 and C4 act through CR1/CR2 to enhance humoral immunity and somehow suppress autoimmunity. Here we report high titers of spontaneous antinuclear antibody (ANA) in C4−/− mice. This systemic lupus erythematosus–like autoimmunity is highly penetrant; by 10 mo of age, all C4−/− females and most males produced ANA. In contrast, titers and frequencies of ANA in Cr2−/− mice, which are deficient in CR1 and CR2, never rose significantly above those in normal controls. Glomerular deposition of immune complexes (ICs), glomerulonephritis, and splenomegaly were observed in C4−/− but not Cr2−/− mice. C4−/−, but not Cr2−/−, mice accumulate activated T and B cells. Clearance of circulating ICs is impaired in preautoimmune C4−/−, but not Cr2−/−, mice. C4 deficiency causes spontaneous, lupus-like autoimmunity through a mechanism that is independent of CR1/CR2.

scholarly journals Induction of autoreactive B cells allows priming of autoreactive T cells.

1991 ◽  
Vol 173 (6) ◽  
pp. 1433-1439 ◽  
Author(s):  
R H Lin ◽  
M J Mamula ◽  
J A Hardin ◽  
C A Janeway
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
Cytochrome C ◽  
Autoantibody Production ◽  
Autoreactive T Cells ◽  
Human Cytochrome ◽  
Self Tolerance ◽  
Human Cytochrome C

A novel mechanism for breaking T cell self tolerance is described. B cells induced to make autoantibody by immunization of mice with the non-self protein human cytochrome c can present the self protein mouse cytochrome c to autoreactive T cells in immunogenic form. This mechanism of breaking T cell self tolerance could account for the role of foreign antigens in breaking not only B cell but also T cell self tolerance, leading to sustained autoantibody production in the absence of the foreign antigen.

scholarly journals Deep Phenotyping of CD11c+ B Cells in Systemic Autoimmunity and Controls

2021 ◽  
Vol 12 ◽  
Author(s):  
Hector Rincon-Arevalo ◽  
Annika Wiedemann ◽  
Ana-Luisa Stefanski ◽  
Marie Lettau ◽  
Franziska Szelinski ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Lupus Erythematosus ◽  
Cell Activation ◽  
B Cell Activation ◽  
Membrane Expression ◽  
Ki 67 ◽  
Inflammatory Conditions ◽  
Systemic Autoimmunity ◽  
Enhanced Expression

Circulating CD11c+ B cells are a key phenomenon in certain types of autoimmunity but have also been described in the context of regular immune responses (i.e., infections, vaccination). Using mass cytometry to profile 46 different markers on individual immune cells, we systematically initially confirmed the presence of increased CD11c+ B cells in the blood of systemic lupus erythematosus (SLE) patients. Notably, significant differences in the expression of CD21, CD27, and CD38 became apparent between CD11c− and CD11c+ B cells. We observed direct correlation of the frequency of CD21−CD27− B cells and CD21−CD38− B cells with CD11c+ B cells, which were most pronounced in SLE compared to primary Sjögren's syndrome patients (pSS) and healthy donors (HD). Thus, CD11c+ B cells resided mainly within memory subsets and were enriched in CD27−IgD−, CD21−CD27−, and CD21−CD38− B cell phenotypes. CD11c+ B cells from all donor groups (SLE, pSS, and HD) showed enhanced CD69, Ki-67, CD45RO, CD45RA, and CD19 expression, whereas the membrane expression of CXCR5 and CD21 were diminished. Notably, SLE CD11c+ B cells showed enhanced expression of the checkpoint molecules CD86, PD1, PDL1, CD137, VISTA, and CTLA-4 compared to HD. The substantial increase of CD11c+ B cells with a CD21− phenotype co-expressing distinct activation and checkpoint markers, points to a quantitative increased alternate (extrafollicular) B cell activation route possibly related to abnormal immune regulation as seen under the striking inflammatory conditions of SLE which shows a characteristic PD-1/PD-L1 upregulation.

scholarly journals Dual T cell– and B cell–intrinsic deficiency in humans with biallelic RLTPR mutations

2016 ◽  
Vol 213 (11) ◽  
pp. 2413-2435 ◽  
Author(s):  
Yi Wang ◽  
Cindy S. Ma ◽  
Yun Ling ◽  
Aziz Bousfiha ◽  
Yildiz Camcioglu ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Cd4 T Cells ◽  
Ex Vivo ◽  
Cell Phenotype ◽  
Loss Of Function ◽  
Inborn Errors

Combined immunodeficiency (CID) refers to inborn errors of human T cells that also affect B cells because of the T cell deficit or an additional B cell–intrinsic deficit. In this study, we report six patients from three unrelated families with biallelic loss-of-function mutations in RLTPR, the mouse orthologue of which is essential for CD28 signaling. The patients have cutaneous and pulmonary allergy, as well as a variety of bacterial and fungal infectious diseases, including invasive tuberculosis and mucocutaneous candidiasis. Proportions of circulating regulatory T cells and memory CD4+ T cells are reduced. Their CD4+ T cells do not respond to CD28 stimulation. Their CD4+ T cells exhibit a "Th2" cell bias ex vivo and when cultured in vitro, contrasting with the paucity of "Th1," "Th17," and T follicular helper cells. The patients also display few memory B cells and poor antibody responses. This B cell phenotype does not result solely from the T cell deficiency, as the patients’ B cells fail to activate NF-κB upon B cell receptor (BCR) stimulation. Human RLTPR deficiency is a CID affecting at least the CD28-responsive pathway in T cells and the BCR-responsive pathway in B cells.

Reduced expression of hematopoietic progenitor kinase 1 in T follicular helper cells causes autoimmunity of systemic lupus erythematosus

Lupus ◽  
2021 ◽  
pp. 096120332110625
Author(s):  
Huilin Zhang ◽  
Yuming Xie ◽  
Junke Huang ◽  
Danhong Luo ◽  
Qing Zhang
Keyword(s):  
Systemic Lupus Erythematosus ◽  
B Cells ◽  
Lupus Erythematosus ◽  
Damage Index ◽  
Enzyme Linked Immunosorbent Assay ◽  
Systemic Lupus ◽  
Hematopoietic Progenitor ◽  
Protein Levels ◽  
Tfh Cells ◽  
Follicular Helper

Backgroud T follicular helper (Tfh) cells have been discovered to be the main CD4+ T cells assisting B cells to produce antibody. They are over activated in patients with systemic lupus erythematosus (SLE) and consequently lead to excessive immunity. Hematopoietic progenitor kinase 1 (HPK1) negatively regulates T cell-mediated immune responses and TCR signal. This study aimed to investigate the roles of HPK1 in SLE Tfh cells. Methods HPK1 mRNA and protein levels in Tfh cells were measured by real-time quantitative PCR and western blot analysis, respectively. The production of IL-21, B cell−activating factor (BAFF), interferon γ (IFNγ), IL-17A, IgM, IgG1, IgG2, and IgG3 were analyzed using enzyme linked immunosorbent assay. Tfh cells proliferation was evaluated with 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Results HPK1 mRNA and protein levels were significantly reduced in SLE Tfh cells, and negatively correlated with SLE disease activity index (SLEDAI) and Systemic Lupus International Collaborating Clinics/American College of Rheumatology (SLICC/ACR) Damage Index for SLE (SDI). Knocking down HPK1 with siRNA in normal Tfh cells greatly elevated Tfh cells proliferation and secretions of IL-21, BAFF, IFNγ, IgG1, IgG2, and IgG3. There were no marked alterations in IL-17A and IgM productions. The opposite effects were observed in SLE Tfh cells transfected with HPK1 overexpressing plasmid: Tfh cells proliferation and productions of IL-21, BAFF, IFNγ, IgG1, IgG2, and IgG3 were all alleviated. And there were no significant changes in IL-17A and IgM levels. Conclusion Our results suggest for the first time that inhibited expression of HPK1 in SLE Tfh cells leading to Tfh cells overactivation and B cells overstimulation, subsequently, the onset and progression of SLE.

CD8 Expression on B Cells in Chronic Lymphocytic Leukemia

2000 ◽  
Vol 124 (9) ◽  
pp. 1361-1363
Author(s):  
Anwarul Islam ◽  
Adrian O. Vladutiu ◽  
Theresa Donahue ◽  
Selina Akhter ◽  
Amy M. Sands ◽  
...  
Keyword(s):  
Bone Marrow ◽  
T Cell ◽  
B Cells ◽  
Chronic Lymphocytic Leukemia ◽  
Tract Infection ◽  
Respiratory Tract ◽  
Respiratory Tract Infection ◽  
Peripheral Blood ◽  
Lymphocytic Leukemia ◽  
Cell Antigen

Abstract The expression of CD8, a restricted T-cell antigen, on B cells in B chronic lymphocytic leukemia is rare, and its significance, if any, remains unknown. We report herein a patient with B chronic lymphocytic leukemia in whom CD8 was strongly expressed on all B cells, both in the bone marrow and peripheral blood. The patient required no therapy for 6 years after being diagnosed as having B chronic lymphocytic leukemia. Then, when the disease progressed, he was treated with conventional doses of fludarabine phosphate (25 mg/m2 daily for 5 days), but unlike other patients with B chronic lymphocytic leukemia he tolerated this therapy poorly. He received a total of only 4 series of fludarabine therapy, and following each course of treatment, he developed considerable myelosuppression. After the fourth course of therapy, his bone marrow failed to show any evidence of regeneration, and he died as a result of intercurrent respiratory tract infection 1 month after his last dose of fludarabine was given.

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