Pyruvate Kinase Isoenzyme M2 Impairs Cognition in Systemic Lupus Erythematosus by Promoting Microglial Synaptic Pruning via β-Catenin Signaling Pathway

Author(s):  
Li Lu ◽  
Hailin Wang ◽  
Xuan Liu ◽  
Liping Tan ◽  
Xiaoyue Qiao ◽  
...  

Abstract Background Neuropsychiatric systemic lupus erythematosus (NPSLE) is the severest complication of SLE, which often involves pathological damage to the brain and cognitive function. Glucose metabolic changes are observed in SLE patients with cognitive impairments by medical imaging. Pyruvate kinase isoform M2 (PKM2) is a vital catalyzer of glucose catabolic pathways and in neurological diseases. However, PKM2 regarding the progress of NPSLE remains poorly studied. Thus, this study aimed to analyze and compare the central carbon metabolites in the validated neuropsychiatric lupus model and control mice. Methods MRL/Mp-Faslpr (MRL/lpr) female mice were used as NPSLE mouse model, C57BL6 as control. Metabolomics to assess hippocampa glycolysis level. Glucose, lactic acid, IL-6 and IL-1β of hippocampal were detected by ELISA. The expression of PKM2 was detected by qRT-PCR and western blotting, and the localization of PKM2 in microglia and neurons was assessed with IBA-1, NeuN and PKM2 immunohistochemistry. Flow cytometry was used to detect the number and phenotype of microglia. In vitro, after transfected PKM2 overexpression plasmid on BV2, the effect on microglia and β-catenin signaling pathway were detected. Finally, PKM2 inhibitor Shikonin was injected into MRL/lpr mice, behavioral testing were performed to assess cognition, HE and FJB staining were used to evaluate brain damage.Results Glycolysis was elevated in the hippocampal tissues from MRL/lpr lupus mice, accompanied by an increase in glucose consumption and lactate production. Based on these metabolic variations, PKM2 activation was revealed in hippocampal microglia from lupus mice. Furthermore, PKM2 facilitated microglial phagocytic activity and engulfment of neurons via β-catenin signaling. In vivo, an inhibitor of PKM2, Shikonin, was shown to reduce microglial activation, loss of neuronal synapses, and block β-catenin signaling. Accordingly, the cognitive impairment and brain damage of MRL/lpr mice were relieved. Conclusion These results indicated that abnormal glycolytic metabolism in the brain tissue of NPSLE mice was induced by PKM2 overexpression, which increased the activation of microglia and the ability of phagocytizing neuronal synapses, leading to neuronal loss and cognitive dysfunction in lupus. These phenomena indicated that inhibition on PKM2 would be a novel therapeutic target for the treatment of lupus encephalopathy.

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 230.2-231
Author(s):  
A. Pappalardo ◽  
E. Wojciechowski ◽  
I. Odriozola ◽  
I. Douchet ◽  
N. Merillon ◽  
...  

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


2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 21.2-21
Author(s):  
S. R. Dillon ◽  
L. S. Evans ◽  
K. E. Lewis ◽  
J. Yang ◽  
M. W. Rixon ◽  
...  

Background:BAFF and APRIL are TNF superfamily members that form homo- and heteromultimers that bind TACI and BCMA on B cells; BAFF also binds BAFF-R. BAFF and APRIL support B cell development, differentiation, and survival, particularly for plasmablasts and plasma cells, and play critical roles in the pathogenesis of B cell-related autoimmune diseases. In nonclinical models, inhibition of either BAFF or APRIL alone mediates relatively modest effects, whereas their co-neutralization dramatically reduces B cell function, including antibody production. Fc fusions of wild-type (WT) TACI (e.g. atacicept and telitacicept) target both BAFF and APRIL and have demonstrated promising clinical potential in e.g. systemic lupus erythematosus (SLE) and IgA nephropathy but have not yet clearly exhibited long-term and/or complete disease remissions.Objectives:To generate a dual BAFF/APRIL antagonist with inhibitory activity superior to WT TACI and BCMA and with the potential to improve clinical outcomes in B cell-mediated diseases.Methods:Our directed evolution platform was used to identify a potent variant TNFR domain (vTD) of TACI that exhibits significantly enhanced affinity for BAFF and APRIL as compared to WT TACI; this TACI vTD domain was fused to a human IgG Fc to generate the therapeutic candidate ALPN-303. ALPN-303 was evaluated for functional activity in: 1) human lymphocyte assays, 2) the NOD.Aec1Aec2 spontaneous model of Sjogren’s syndrome (SjS), 3) the bm12-induced mouse model of lupus, 4) the (NZB/NZW)F1 spontaneous model of lupus, and 5) preclinical rodent and cynomolgus monkey pharmacokinetic/pharmacodynamic studies.Results:ALPN-303 inhibited BAFF- and APRIL-mediated signaling in vitro in human lymphocyte assays, with significantly lower IC50 values than WT TACI-Fc and belimumab comparators. In all mouse models evaluated, administration of ALPN-303 rapidly and significantly reduced key lymphocyte subsets including plasma cells, germinal center B cells, and follicular T helper cells. ALPN-303 significantly reduced autoantibodies and sialadenitis in the spontaneous SjS model, inhibited glomerular IgG deposition in the bm12-induced model of lupus, and potently suppressed anti-dsDNA autoAbs, blood urea nitrogen levels, proteinuria, sialadenitis, kidney lesions, and renal immune complex deposition in the NZB/W lupus model. As compared to WT TACI-Fc, ALPN-303 exhibited higher serum exposure and significantly and persistently decreased titers of serum IgM, IgG, and IgA antibodies in mice and cynomolgus monkeys (Figure 1).Figure 1.ALPN-303 induces more potent suppression, as compared to WT TACI-Fc, of serum immunoglobulins following a single 9 mg/kg IV infusion (on Day 0; arrows) in female cynomolgus monkeys.Conclusion:ALPN-303 is a potent BAFF/APRIL antagonist derived from our directed evolution platform that consistently demonstrates encouraging immunomodulatory activity and efficacy in vitro and in vivo, superior in preclinical studies to anti-BAFF antibody and WT TACI-Fc. This novel Fc fusion molecule demonstrates favorable preliminary developability characteristics, including higher serum exposures and more potent immunosuppressive activities, which may enable lower clinical doses and/or longer dosing intervals than WT TACI-Fc therapeutics. ALPN-303 may thus be an attractive development candidate for the treatment of multiple autoimmune and inflammatory diseases, particularly B cell-related diseases such as SLE, SjS, and other connective tissue diseases. Preclinical development is underway to enable the initiation of clinical trials later this year.Disclosure of Interests:Stacey R. Dillon Shareholder of: Alpine Immune Sciences, Bristol Myers Squibb, Employee of: Alpine Immune Sciences, Bristol Myers Squibb, Lawrence S. Evans Shareholder of: Alpine Immune Sciences, Employee of: Alpine Immune Sciences, Katherine E. Lewis Shareholder of: Alpine Immune Sciences, Employee of: Alpine Immune Sciences, Jing Yang Shareholder of: Alpine Immune Sciences, Employee of: Alpine Immune Sciences, Mark W. Rixon Shareholder of: Alpine Immune Sciences, Employee of: Alpine Immune Sciences, Joe Kuijper Shareholder of: Alpine Immune Sciences, Employee of: Alpine Immune Sciences, Dan Demonte Shareholder of: Alpine Immune Sciences, Employee of: Alpine Immune Sciences, Janhavi Bhandari Shareholder of: Alpine Immune Sciences, Employee of: Alpine Immune Sciences, Steve Levin Shareholder of: Alpine Immune Sciences, Employee of: Alpine Immune Sciences, Kayla Kleist Shareholder of: Alpine Immune Sciences, Employee of: Alpine Immune Sciences, Sherri Mudri Shareholder of: Alpine Immune Sciences, Employee of: Alpine Immune Sciences, Susan Bort Shareholder of: Alpine Immune Sciences, Employee of: Alpine Immune Sciences, Daniel Ardourel Shareholder of: Alpine Immune Sciences, Employee of: Alpine Immune Sciences, Michelle A. Seaberg Shareholder of: Alpine Immune Sciences, Employee of: Alpine Immune Sciences, Rachel Wang Shareholder of: Alpine Immune Sciences, Employee of: Alpine Immune Sciences, Chelsea Gudgeon Shareholder of: Alpine Immune Sciences, Employee of: Alpine Immune Sciences, Russell Sanderson Shareholder of: Alpine Immune Sciences, Employee of: Alpine Immune Sciences, Martin F. Wolfson Shareholder of: Alpine Immune Sciences, Employee of: Alpine Immune Sciences, Jan Hillson Shareholder of: Alpine Immune Sciences, Employee of: Alpine Immune Sciences, Stanford L. Peng Shareholder of: Alpine Immune Sciences, Employee of: Alpine Immune Sciences


1982 ◽  
Vol 2 (12) ◽  
pp. 1492-1500
Author(s):  
Marshall S. Horwitz ◽  
Beth R. Friefeld ◽  
Harold D. Keiser

Sera containing antinuclear antibodies from patients with systemic lupus erythematosus (SLE) and related disorders were tested for their effect on the synthesis of adenovirus (Ad) DNA in an in vitro replication system. After being heated at 60°C for 1 h, some sera from patients with SLE inhibited Ad DNA synthesis by 60 to 100%. Antibodies to double-stranded DNA were present in 15 of the 16 inhibitory sera, and inhibitory activity copurified with anti-double-stranded DNA in the immunoglobulin G fraction. These SLE sera did not inhibit the DNA polymerases α, β, γ and had no antibody to the 72,000-dalton DNA-binding protein necessary for Ad DNA synthesis. The presence of antibodies to single-stranded DNA and a variety of saline-extractable antigens (Sm, Ha, nRNP, and rRNP) did not correlate with SLE serum inhibitory activity. Methods previously developed for studying the individual steps in Ad DNA replication were used to determine the site of inhibition by the SLE sera that contained antibody to double-stranded DNA. Concentrations of the SLE inhibitor that decreased the elongation of Ad DNA by greater than 85% had no effect on either the initiation of Ad DNA synthesis or the polymerization of the first 26 deoxyribonucleotides.


Lupus ◽  
2018 ◽  
Vol 28 (1) ◽  
pp. 133-136 ◽  
Author(s):  
H. Furuya ◽  
K. Ikeda ◽  
K. Iida ◽  
K. Suzuki ◽  
S. Furuta ◽  
...  

Toxoplasma is a common parasite worldwide that mainly affects the brain, lungs and eyes. Although toxoplasmic encephalitis is a lethal disease without treatment, past case reports show most patients with systemic lupus erythematosus who developed toxoplasmic encephalitis were misdiagnosed and treated as neuropsychiatric systemic lupus erythematosus, which led to unfavorable outcomes. We herein describe a case of disseminated toxoplasmosis affecting all the above organs with atypical symptoms, which developed with exacerbation of systemic lupus erythematosus. She had initially manifested with retinochoroiditis without vitritis, mild cognitive impairment and an isolated lung mass. These are completely different from the classic symptoms of toxoplasmosis that have been reported in patients with HIV infection and/or those after hematopoietic transplantation. Our case, together with previously reported cases, suggests the manifestation of toxoplasmosis that develops in systemic lupus erythematosus patients can be different from that seen in conventional cases and varies between individual patients. Our case highlights both the difficulty in and the importance of diagnosing toxoplasmosis in patients with systemic lupus erythematosus and provides helpful information to identify this rare, devastating, yet treatable disease.


2020 ◽  
Author(s):  
Sarthak Gupta ◽  
Shuichiro Nakabo ◽  
Jun Chu ◽  
Sarfaraz Hasni ◽  
Mariana J. Kaplan

AbstractObjectivesAnti-type I interferon (IFN) autoantibodies have been reported in patients with systemic lupus erythematosus (SLE). Recently, an association of these autoantibodies with severe COVID-19 was reported in the general population. We assessed whether having pre-existing anti-IFNα autoantibodies was associated with COVID-19 infection in SLE patients.MethodsPatients with SLE who developed COVID-19 between April 1st to October 1st, 2020 were studied. Biobanked pre-COVID-19 plasma from these SLE subjects and healthy controls were tested for anti-IFNα IgG autoantibodies by ELISA. The ability of plasma anti-IFNα autoantibodies to block signal transducer and activator of transcription 1 (STAT1) phosphorylation by recombinant human IFNα in vitro was assessed by flow cytometry.ResultsTen SLE subjects with COVID-19 were identified. A 40% of these subjects had stable autoantibodies against IFNα for up to three years preceding COVID-19 diagnosis. A 50% of the subjects with these autoantibodies neutralized IFNα induced STAT1 phosphorylation.None of the other SLE samples blocked IFNα signaling.ConclusionsWe noted an increased prevalence of pre-existing anti-IFNα autoantibodies in SLE patients with COVID-19 compared to the reported prevalence in lupus patients and the general population with severe COVID-19. Autoantibodies against IFNα in SLE patients may be pathogenic and patients with them maybe at-risk of developing COVID-19.Key MessagesWhat is already known about this subject?-Anti-type I interferon (IFN) autoantibodies have been reported in patients with systemic lupus erythematosus (SLE) and have recently been associated with severe COVID-19 in the general population.What does this study add?-SLE subjects with COVID-19 had an increased prevalence of pre-existing anti-IFNα autoantibodies compared to the reported prevalence in lupus patients and the general population with severe COVID-19.-Plasma from 50% of subjects with these autoantibodies were able to block in vitro activity of IFNα.-SLE patients with pre-existing anti-IFNα autoantibodies had more severe COVID-19 manifestations.How might this impact on clinical practice or future developments?-Anti-IFNα autoantibodies may be pathogenic and could prove to be a helpful prognostic marker to predict which SLE patient may develop COVID-19 and inform preventive measures and management of this subset of patients.


Blood ◽  
1986 ◽  
Vol 67 (2) ◽  
pp. 479-483
Author(s):  
T Nagasawa ◽  
T Sakurai ◽  
H Kashiwagi ◽  
T Abe

We studied a patient with a rare complication of amegakaryocytic thrombocytopenia (AMT) associated with systemic lupus erythematosus (SLE). To investigate the underlying pathogenesis of AMT, the effects of peripheral blood T cells and serum on human megakaryocyte progenitor cells were studied using in vitro coculture techniques. Mononuclear bone marrow cells (2 X 10(5) from normal donors produced 33.6 +/- 8.8 (n = 10) colony-forming unit-megakaryocytes (CFU-M) in our plasma clot system. When 2 X 10(5) of the patient's T cells were added to the culture system, the number of CFU-M decreased to only 3.5 +/- 0.6/2 X 10(5) bone marrow cells. No evidence of inhibitory effects was found by the addition of the patient's serum and complement to the culture system. The T cells stored at -80 degrees C on admission were also capable of suppressing autologous CFU-M after recovery from AMT. These results indicate that in vitro suppression of CFU-M from allogenic and autologous bone marrow cells by this patient's T cells provides an explanation for the pathogenesis of AMT associated with SLE.


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