B cells in systemic lupus erythematosus

Background:Systemic lupus erythematosus (SLE) is characterized by two pathogenic key signatures, type I interferon (IFN) (1.) and B-cell abnormalities (2.). How these signatures are interrelated is not known. Type I-II IFN trigger activation of Janus kinase (JAK) – signal transducer and activator of transcription (STAT).Objectives:JAK-STAT inhibition is an attractive therapeutic possibility for SLE (3.). We assess STAT1 and STAT3 expression and phosphorylation at baseline and after IFN type I and II stimulation in B-cell subpopulations of SLE patients compared to other autoimmune diseases and healthy controls (HD) and related it to disease activity.Methods:Expression of STAT1, pSTAT1, STAT3 and pSTAT3 in B and T-cells of 21 HD, 10 rheumatoid arthritis (RA), 7 primary Sjögren’s (pSS) and 22 SLE patients was analyzed by flow cytometry. STAT1 and STAT3 expression and phosphorylation in PBMCs of SLE patients and HD after IFNα and IFNγ incubation were further investigated.Results:SLE patients showed substantially higher STAT1 but not pSTAT1 in B and T-cell subsets. Increased STAT1 expression in B cell subsets correlated significantly with SLEDAI and Siglec-1 on monocytes, a type I IFN marker (4.). STAT1 activation in plasmablasts was IFNα dependent while monocytes exhibited dependence on IFNγ.Figure 1.Significantly increased expression of STAT1 by SLE B cells(A) Representative histograms of baseline expression of STAT1, pSTAT1, STAT3 and pSTAT3 in CD19+ B cells of SLE patients (orange), HD (black) and isotype controls (grey). (B) Baseline expression of STAT1 and pSTAT1 or (C) STAT3 and pSTAT3 in CD20+CD27-, CD20+CD27+ and CD20lowCD27high B-lineage cells from SLE (orange) patients compared to those from HD (black). Mann Whitney test; ****p≤0.0001.Figure 2.Correlation of STAT1 expression by SLE B cells correlates with type I IFN signature (Siglec-1, CD169) and clinical activity (SLEDAI).Correlation of STAT1 expression in CD20+CD27- näive (p<0.0001, r=0.8766), CD20+CD27+ memory (p<0.0001, r=0.8556) and CD20lowCD27high (p<0.0001, r=0.9396) B cells from SLE patients with (A) Siglec-1 (CD169) expression on CD14+ cells as parameter of type I IFN signature and (B) lupus disease activity (SLEDAI score). Spearman rank coefficient (r) was calculated to identify correlations between these parameters. *p≤0.05, **p≤0.01. (C) STAT1 expression in B cell subsets of a previously undiagnosed, active SLE patient who was subsequently treated with two dosages of prednisolone and reanalyzed.Conclusion:Enhanced expression of STAT1 by B-cells candidates as key node of two immunopathogenic signatures (type I IFN and B-cells) related to important immunopathogenic pathways and lupus activity. We show that STAT1 is activated upon IFNα exposure in SLE plasmablasts. Thus, Jak inhibitors, targeting JAK-STAT pathways, hold promise to block STAT1 expression and control plasmablast induction in SLE.References:[1]Baechler EC, Batliwalla FM, Karypis G, Gaffney PM, Ortmann WA, Espe KJ, et al. Interferon-inducible gene expression signature in peripheral blood cells of patients with severe lupus. Proc Natl Acad Sci U S A. 2003;100(5):2610-5.[2]Lino AC, Dorner T, Bar-Or A, Fillatreau S. Cytokine-producing B cells: a translational view on their roles in human and mouse autoimmune diseases. Immunol Rev. 2016;269(1):130-44.[3]Dorner T, Lipsky PE. Beyond pan-B-cell-directed therapy - new avenues and insights into the pathogenesis of SLE. Nat Rev Rheumatol. 2016;12(11):645-57.[4]Biesen R, Demir C, Barkhudarova F, Grun JR, Steinbrich-Zollner M, Backhaus M, et al. Sialic acid-binding Ig-like lectin 1 expression in inflammatory and resident monocytes is a potential biomarker for monitoring disease activity and success of therapy in systemic lupus erythematosus. Arthritis Rheum. 2008;58(4):1136-45.Disclosure of Interests:Arman Aue: None declared, Franziska Szelinski: None declared, Sarah Weißenberg: None declared, Annika Wiedemann: None declared, Thomas Rose: None declared, Andreia Lino: None declared, Thomas Dörner Grant/research support from: Janssen, Novartis, Roche, UCB, Consultant of: Abbvie, Celgene, Eli Lilly, Roche, Janssen, EMD, Speakers bureau: Eli Lilly, Roche, Samsung, Janssen

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THU0035 OX40L EXPRESSING NEUTROPHILS INDUCE CD4 T FOLLICULAR AND PERIPHERAL HELPER CELL DIFFERENTIATION IN SYSTEMIC LUPUS ERYTHEMATOSUS

Annals of the Rheumatic Diseases ◽

10.1136/annrheumdis-2020-eular.2739 ◽

2020 ◽

Vol 79 (Suppl 1) ◽

pp. 230.2-231

Author(s):

A. Pappalardo ◽

E. Wojciechowski ◽

I. Odriozola ◽

I. Douchet ◽

N. Merillon ◽

...

Keyword(s):

Systemic Lupus Erythematosus ◽

T Cells ◽

B Cells ◽

Lupus Erythematosus ◽

Cd4 T Cells ◽

Close Contact ◽

Memory B Cells ◽

Systemic Lupus ◽

Research Support

Background:Neutrophils have been described as potent antigen-presenting cells able to activate T cells by MHC/TCR interaction and costimulatory molecules in tumor immunity. However, little is known about the direct interaction between neutrophils and CD4 T cells with respect to systemic lupus erythematosus (SLE). We have previously shown that OX40L expressed by monocytes from SLE patients promote the differentiation of naïve and memory cells into IL21 secreting T cells that are able to help B cells1,2.Objectives:In this study, we investigate OX40L expression on neutrophils from SLE patients and contribution of these OX40L+neutrophils in SLE pathogenesis to modulation of the B cell helper role of CD4 T cells.Methods:Surface expression of co-stimulatory molecules (OX40L, ICOSL, GITRL, 4-1BBL) on neutrophils from SLE patients and healthy donors (HD) was measured by flow cytometry (FC). Neutrophils from HD were stimulated with TLR7 or TLR8 agonists and IFNα after 5 hours of culture, OX40L expression was measured by FC and Western Blotting. CD4 T cells were cultured with the stimulated neutrophils for 3 days. At the end of the co-culture, percentages of IL21-expressing T follicular (Tfh) and peripheral helper (Tph) cells measured by FC. These generated T cells were also cultured in the presence of memory B cells. After 5 days of co-culture, plasmablast generation and Ig levels were assessed by FC and ELISA, respectively. Inhibition of OX40-OX40L interaction in vitro was achieved using ISB 830, a novel anti-OX40 mAb currently used in clinical trials.Results:Among the co-stimulatory molecules tested, percentages of OX40L+neutrophils in SLE (n=54) were increased compared to HD (n=25)(mean + SD: HD = 1,34%±1.62 vs SLE = 4,53%±8.1; p=0.29). OX40L expression positively correlated with SLE disease activity score (SLEDAI) (p = 0,04; r = 0,31) and with anti-DNA antibodies (p= 0,04, r = 0,33). Of note, the percentage of OX40L+neutrophils was higher in anti-sm-RNP+patients (n=16, mean= 9%±9.8), compared to anti-sm-RNP-patients (n=27, mean = 1,4%±2.5; p = 0,02). The percentage of OX40L+neutrophils was higher in patients with class III or IV lupus nephritis, and inflammatory infiltrate within the kidney biopsy disclosed OX40L+neutrophils, in close contact with T cells. Neutrophils from HD express OX40L with TLR8 agonist, or IFNα priming followed by TLR7 agonist. When memory CD4 T cells were cultured in the presence of TLR8-stimulated neutrophils, the proportion of IL21-expressing Tfh (CXCR5+PD1+) and Tph (CXCR5-PD1hi) were increased, compared to culture with unstimulated neutrophils. This process was dependent on OX40-OX40L interactions, since in vitro treatment with the anti-OX40 blocking antibody ISB 830, inhibited the differentiation of memory T cells into Tfh and Tph. Both generated Tfh and Tph were able to promote the differentiation of memory B cells into Ig-secreting plasmablasts.Conclusion:Our results disclose an unprecedented phenomenon where cross-talk between TLR7/8-activated neutrophils and CD4 lymphocytes operates through OX40L-OX40 costimulation, and neutrophils promote the differentiation of pro-inflammatory Tfh and Tph, as well as IL21 production. Therefore, OX40L/OX40 should be considered as a potentially therapeutic axis in SLE patients.References:[1]Jacquemin et al. Immunity 2015;[2]Jacquemin et al. JCI Insight 2018Disclosure of Interests:Angela Pappalardo Grant/research support from: Ichnos Sciences, Elodie Wojciechowski: None declared, Itsaso Odriozola: None declared, Isabelle Douchet: None declared, Nathalie Merillon: None declared, Andrea Boizard-Moracchini: None declared, Pierre Duffau: None declared, Estibaliz Lazaro: None declared, Marie-Agnes Doucey Employee of: Ichnos Sciences, Lamine Mbow Employee of: Ichnos Sciences, Christophe Richez Consultant of: Abbvie, Amgen, Mylan, Pfizer, Sandoz and UCB., Patrick Blanco Grant/research support from: Ichnos Sciences

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The expansion of activated naive DNA autoreactive B cells and its association with disease activity in systemic lupus erythematosus patients

Arthritis Research & Therapy ◽

10.1186/s13075-021-02557-0 ◽

2021 ◽

Vol 23 (1) ◽

Author(s):

Kittikorn Wangriatisak ◽

Chokchai Thanadetsuntorn ◽

Thamonwan Krittayapoositpot ◽

Chaniya Leepiyasakulchai ◽

Thanitta Suangtamai ◽

...

Keyword(s):

Systemic Lupus Erythematosus ◽

B Cells ◽

Disease Activity ◽

B Cell ◽

Lupus Erythematosus ◽

Systemic Lupus ◽

Autoreactive B Cells ◽

Dsdna Antibody ◽

Cell Subpopulations ◽

B Cell Subsets

Abstract Background Autoreactive B cells are well recognized as key participants in the pathogenesis of systemic lupus erythematosus (SLE). However, elucidating the particular subset of B cells in producing anti-dsDNA antibodies is limited due to their B cell heterogeneity. This study aimed to identify peripheral B cell subpopulations that display autoreactivity to DNA and contribute to lupus pathogenesis. Methods Flow cytometry was used to detect total B cell subsets (n = 20) and DNA autoreactive B cells (n = 15) in SLE patients’ peripheral blood. Clinical disease activities were assessed in SLE patients using modified SLEDAI-2 K and used for correlation analyses with expanded B cell subsets and DNA autoreactive B cells. Results The increases of circulating double negative 2 (DN2) and activated naïve (aNAV) B cells were significantly observed in SLE patients. Expanded B cell subsets and DNA autoreactive B cells represented a high proportion of aNAV B cells with overexpression of CD69 and CD86. The frequencies of aNAV B cells in total B cell populations were significantly correlated with modified SLEDAI-2 K scores. Further analysis showed that expansion of aNAV DNA autoreactive B cells was more related to disease activity and serum anti-dsDNA antibody levels than to total aNAV B cells. Conclusion Our study demonstrated an expansion of aNAV B cells in SLE patients. The association between the frequency of aNAV B cells and disease activity patients suggested that these expanded B cells may play a role in SLE pathogenesis.

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THU0231 IL-2 DRIVES THE CONVERSION OF T FOLLICULAR HELPER TO T FOLLICULAR REGULATORY CELLS THROUGH EPIGENETIC MODIFICATION IN SYSTEMIC LUPUS ERYTHEMATOSUS

Annals of the Rheumatic Diseases ◽

10.1136/annrheumdis-2020-eular.651 ◽

2020 ◽

Vol 79 (Suppl 1) ◽

pp. 343.2-343

Author(s):

H. Hao ◽

S. Nakayamada ◽

Y. Kaoru ◽

N. Ohkubo ◽

S. Iwata ◽

...

Keyword(s):

Systemic Lupus Erythematosus ◽

Flow Cytometry ◽

B Cells ◽

Histone Modifications ◽

Lupus Erythematosus ◽

Regulatory Cells ◽

Systemic Lupus ◽

Research Support ◽

Tfh Cells ◽

Follicular Helper

Background:Systemic lupus erythematosus (SLE) is a complex polygenic autoimmune disease characterized by immune-system aberrations. Among several types of immune cells, T follicular helper (Tfh) cells promote autoantibody production, whereas T follicular regulatory (Tfr) cells suppress Tfh-mediated antibody responses.(1)Objectives:To identify the characteristics of Tfr cells and to elucidate the mechanisms of conversion of Tfh cells to Tfr cells, we probed the phenotype of T helper cells in patients with SLE and underlying epigenetic modifications by cytokine-induced signal transducer and activators of transcription (STAT) family factors.Methods:Peripheral blood mononuclear cells from SLE patients (n=44) and healthy donors (HD; n=26) were analyzed by flow cytometry. Memory Tfh cells were sorted and cultured under stimulation with T cell receptor and various cytokines. Expression of characteristic markers and phosphorylation of STATs (p-STATs) were analyzed by flow cytometry and quantitation PCR. Histone modifications were evaluated by chromatin immunoprecipitation.Results:The proportion of CXCR5+FoxP3+Tfr cells in CD4+T cells tended to increase (2.1% vs 1.7%, p=0.17); however, that of CD4+CD45RA-FoxP3hiactivated Tfr cells in Tfr cells was decreased (4.8% vs 7.1%, p<0.05), while CD4+CD45RA-FoxP3lownon-suppressive Tfr cells was increased (50.1% vs 38.2%, p<0.01) in SLE compared to HD. The percentage of PD-1hiactivated Tfh cells was significantly higher in SLE compared to HD (15.7% vs 5.9%, p<0.01). Furthermore, active patients had a higher ratio of activated Tfh/Tfr cells compared to inactive patients. In vitro study showed that IL-2, but not other cytokines such as TGF-β1, IL-12, IL-27, and IL-35, induced the conversion of memory Tfh cells to functional Tfr cells characterized by CXCR5+Bcl6+Foxp3hipSTAT3+pSTAT5+cells. The loci ofFOXP3at STAT binding sites were marked by bivalent histone modifications. After IL-2 stimulation, STAT5 directly bound on FOXP3 gene loci accompanied by suppressing H3K27me3. Finally, we found that serum level of IL-2 was decreased in SLE and that stimulation with IL-2 suppressed the generation of CD38+CD27+B cells by ex vivo coculture assay using Tfh cells and B cells isolated from human blood.Conclusion:Our findings indicated that the regulatory function of Tfr cells is impaired due to the low ability of IL-2 production and that IL-2 restores the function of Tfr cells through conversion of Tfh cells to Tfr cells in SLE. Thus, the reinstatement of the balance between Tfh and Tfr cells will provide important therapeutic approaches for SLE.References:[1]Deng J, Wei Y, Fonseca VR, et al. T follicular helper cells and T follicular regulatory cells in rheumatic diseases. Nat Rev Rheumatol. 2019; 15 (8): 475-90.Disclosure of Interests: :He Hao: None declared, Shingo Nakayamada Grant/research support from: Mitsubishi-Tanabe, Takeda, Novartis and MSD, Speakers bureau: Bristol-Myers, Sanofi, Abbvie, Eisai, Eli Lilly, Chugai, Asahi-kasei and Pfizer, Yamagata Kaoru: None declared, Naoaki Ohkubo: None declared, Shigeru Iwata: None declared, Yoshiya Tanaka Grant/research support from: Asahi-kasei, Astellas, Mitsubishi-Tanabe, Chugai, Takeda, Sanofi, Bristol-Myers, UCB, Daiichi-Sankyo, Eisai, Pfizer, and Ono, Consultant of: Abbvie, Astellas, Bristol-Myers Squibb, Eli Lilly, Pfizer, Speakers bureau: Daiichi-Sankyo, Astellas, Chugai, Eli Lilly, Pfizer, AbbVie, YL Biologics, Bristol-Myers, Takeda, Mitsubishi-Tanabe, Novartis, Eisai, Janssen, Sanofi, UCB, and Teijin

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