scholarly journals Knockout of the KH-Type Splicing Regulatory Protein Drives Glomerulonephritis in MRL-Faslpr Mice

Cells ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 3167
Author(s):  
Lisa Schmidtke ◽  
Myriam Meineck ◽  
Sabrina Saurin ◽  
Svenja Otten ◽  
Fabian Gather ◽  
...  
Keyword(s):  
T Cells ◽  
Lupus Nephritis ◽  
Lupus Erythematosus ◽  
Rna Binding ◽  
Regulatory Protein ◽  
Cytokine Expression ◽  
Negative Regulator ◽  
Transcriptional Level ◽  
Kidney Morphology ◽  
The Impact

KH-type splicing regulatory protein (KSRP) is an RNA-binding protein that promotes mRNA decay and thereby negatively regulates cytokine expression at the post-transcriptional level. Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by dysregulated cytokine expression causing multiple organ manifestations; MRL-Faslpr mice are an established mouse model to study lupus disease pathogenesis. To investigate the impact of KSRP on lupus disease progression, we generated KSRP-deficient MRL-Faslpr mice (MRL-Faslpr/KSRP−/− mice). In line with the predicted role of KSRP as a negative regulator of cytokine expression, lupus nephritis was augmented in MRL-Faslpr/KSRP−/− mice. Increased infiltration of immune cells, especially of IFN-γ producing T cells and macrophages, driven by enhanced expression of T cell-attracting chemokines and adhesion molecules, seems to be responsible for worsened kidney morphology. Reduced expression of the anti-inflammatory interleukin-1 receptor antagonist may be another reason for severe inflammation. The increase of FoxP3+ T cells detected in the kidney seems unable to dampen the massive kidney inflammation. Interestingly, lymphadenopathy was reduced in MRL-Faslpr/KSRP−/− mice. Altogether, KSRP appears to have a complex role in immune regulation; however, it is clearly able to ameliorate lupus nephritis.

scholarly journals The RNA-Binding Protein KSRP Modulates Cytokine Expression of CD4+ T Cells

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Rudolf Käfer ◽  
Lisa Schmidtke ◽  
Katharina Schrick ◽  
Evelyn Montermann ◽  
Matthias Bros ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Immune Responses ◽  
Rna Binding ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Cytokine Expression ◽  
Negative Regulator ◽  
Control Group ◽  
Type I

The KH-type splicing regulatory protein (KSRP) is a RNA-binding protein, which regulates the stability of many mRNAs encoding immune-relevant proteins. As KSRP regulates innate immune responses, for instance by the modulation of type I interferon mRNA stability, we were interested whether knockdown of the protein (KSRP-/-) interferes with T cell activation and polarization. Polyclonally stimulated KSRP-/- CD4+ T cells proliferated at a higher extent and higher frequency and expressed the activation marker CD25 more than wild-type T cells. In supernatants of stimulated KSRP-/- CD4+ T cells, levels of IL-5, IL-9, IL-10, and IL-13 were observed to be increased compared to those of the control group. KSRP-/- CD8+ T cells showed no altered proliferative capacity upon polyclonal stimulation, but supernatants contained lower levels of interferon-γ. Similar changes in the cytokine expression patterns were also detected in T cells derived from KSRP-/- mice undergoing arthritis induction indicative of a pathophysiological role of KSRP-dependent T cell polarization. We demonstrated the direct binding of KSRP to the 3′ untranslated region of IL-13, IL-10, and IFN-γ mRNA in in vitro experiments. Moreover, since IL-4 mRNA decay was reduced in KSRP-/- CD4+ T cells, we identify KSRP as a negative regulator of IL-4 expression. These data indicate that overexpression of IL-4, which constitutes the primary inducer of Th2 polarization, may cause the Th2 bias of polyclonally stimulated KSRP-/- CD4+ T cells. This is the first report demonstrating that KSRP is involved in the regulation of T cell responses. We present strong evidence that T cells derived from KSRP-/- mice favor Th2-driven immune responses.

scholarly journals T cell–specific STAT3 deficiency abrogates lupus nephritis

Lupus ◽  
2019 ◽  
Vol 28 (12) ◽  
pp. 1468-1472 ◽  
Author(s):  
N Yoshida ◽  
F He ◽  
V C Kyttaris
Keyword(s):  
T Cells ◽  
T Cell ◽  
Lupus Nephritis ◽  
Lupus Erythematosus ◽  
Cell Responses ◽  
Cytokines And Chemokines ◽  
Novel Approach ◽  
Cell Tissue ◽  
External Stimuli

Signal transducer and activator of transcription (STAT) 3 is a regulator of T-cell responses to external stimuli, such as pro-inflammatory cytokines and chemokines. We have previously shown that STAT3 is activated (phosphorylated) at high levels in systemic lupus erythematosus (SLE) T cells and mediates chemokine-induced migration and T:B cell interactions. Stattic, a small molecular STAT3 inhibitor, can partially ameliorate lupus nephritis in mice. To understand the role of STAT3 better in T-cell pathophysiology in lupus nephritis and its potential as a treatment target, we silenced its expression in T cells using a cd4-driven CRE-Flox model. We found that lupus-prone mice that do not express STAT3 in T cells did not develop lymphadenopathy, splenomegaly, or glomerulonephritis. Moreover, the production of anti-dsDNA antibodies was decreased in these mice compared to controls. To dissect the mechanism, we also used a nephrotoxic serum model of nephritis. In this model, T cell–specific silencing of STAT3 resulted in amelioration of nephrotoxic serum-induced kidney damage. Taken together, our results suggest that in mouse models of autoimmune nephritis, T cell–specific silencing of STAT3 can hamper their ability to help B cells to produce autoantibodies and induce cell tissue infiltration. We propose that STAT3 inhibition in T cells represents a novel approach in the treatment of SLE and lupus nephritis in particular.

scholarly journals Dysregulated T Cell Activation and Aberrant Cytokine Expression Profile in Systemic Lupus Erythematosus

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Haiyan Zhou ◽  
Bojiang Li ◽  
Jing Li ◽  
Tongqian Wu ◽  
Xiaoqian Jin ◽  
...  
Keyword(s):  
Systemic Lupus Erythematosus ◽  
T Cells ◽  
T Cell ◽  
Lupus Erythematosus ◽  
Critical Role ◽  
Cytokine Expression ◽  
Healthy Controls ◽  
Systemic Lupus ◽  
Hla Dr ◽  
Dsdna Antibody

Accumulating evidence indicates a critical role for T cells and relevant cytokines in the pathogenesis of systemic lupus erythematosus (SLE). However, the specific contribution of T cells together with the related circulating cytokines in disease pathogenesis and organ involvement is still not clear. In the current study, we investigated relevant molecule expressions and cytokine levels in blood samples from 49 SLE patients and 22 healthy control subjects. The expression of HLA-DR and costimulatory molecules on T cells was evaluated by flow cytometry. Concentrations of serum C-reactive protein, erythrocyte sedimentation rate, anti-double-stranded DNA (anti-dsDNA) antibody, total lgG, complement 3, and complement 4 were measured. Serum cytokines and chemokines were measured by a cytometric bead array assay. Elevated frequencies of HLA-DR+ T cells and ICOS+ T cells were observed in SLE patients with positive anti-dsDNA antibodies compared with those in healthy controls (P<0.001). The expression of HLA-DR+ T cells was positively correlated with SLEDAI (r=0.15, P<0.01). Furthermore, levels of serum IL-6, MCP-1, TNFRI, IL-10, IL-12, and CCL20 were higher in SLE patients compared with healthy controls. In addition, patients with hematologic manifestations displayed elevated frequencies of HLA-DR+ T cells and ICOS+ T cells. Patients with renal manifestations had a decreased frequency of TIGIT+ T cells. These results suggested a dysregulated T cell activity and cytokine expression profiles in SLE subjects. We also developed a chemokine and cytokine profiling strategy to predict the activity of SLE, which has clinical implication for better monitoring the flares and remission during the course of SLE and for assessing therapeutic interventions.

scholarly journals MO007A PHASE 1B MULTIPLE ASCENDING-DOSE STUDY OF A CD6 TARGETED THERAPY, ITOLIZUMAB, IN SUBJECTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS WITH OR WITHOUT ACTIVE PROLIFERATIVE LUPUS NEPHRITIS

2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Kenneth Kalunian ◽  
Richard Furie ◽  
Jai Radhakrishnan ◽  
Vandana Mathur ◽  
Joel Rothman ◽  
...  
Keyword(s):  
Systemic Lupus Erythematosus ◽  
Monoclonal Antibody ◽  
T Cells ◽  
Lupus Nephritis ◽  
Lupus Erythematosus ◽  
Type A ◽  
Type B ◽  
Systemic Lupus ◽  
Proliferative Lupus Nephritis ◽  
Serologic Markers

Abstract Background and Aims Lupus nephritis (LN) is a leading cause of morbidity and mortality in systemic lupus erythematosus (SLE) patients. T cells are believed to play a central role in the pathogenesis of both SLE and LN. CD6 is a co-stimulatory receptor, predominantly expressed on T cells, that binds to activated leukocyte cell adhesion molecule (ALCAM), a ligand expressed on antigen presenting cells and various epithelial and endothelial tissues. The CD6-ALCAM pathway plays an integral role in modulating T cell activation, proliferation, differentiation and trafficking, and is central to immune mediated inflammation. Itolizumab (EQ001) is a humanized IgG1 monoclonal antibody that binds CD6, blocks the interaction between CD6 and ALCAM, and inhibits both the activation and trafficking of T cells. Inhibiting the CD6-ALCAM pathway with itolizumab potentially represents a promising therapeutic approach for the treatment of LN. The aim of this study is to assess the safety and tolerability, pharmacokinetics, pharmacodynamics, and clinical activity of subcutaneously administered itolizumab in patients with SLE with and without active proliferative lupus nephritis (apLN). Method This cohort-based dose escalation study includes two types of patients: The Type A cohort will enroll ∼24 patients with SLE without apLN (all treated with itolizumab) and the Type B cohort will randomize in a blinded manner ∼36 patients (3:1, itolizumab:placebo) with biopsy-proven ISN/RPS class III or IV (+ V) apLN who have had inadequate response to induction and/or post-induction maintenance treatment, exhibiting urine protein to creatinine ratio [UPCR] ≥1 g/g and active serology. Within both the Type A and Type B cohorts, up to 4 dose groups will be tested (Figure). Background treatments for SLE or LN are allowed. Following 4 weeks of treatment in a new higher dose Type A cohort and recommendation by an independent safety data review committee (DRC), the dose studied in the Type A cohort may then be studied in a Type B Cohort for a 12-week treatment duration (Figure). The primary endpoint is the safety and tolerability of itolizumab. Efficacy endpoints (in the Type B cohorts) include UPCR, estimated glomerular filtration rate, prednisone dose requirements, renal response, Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K), FACIT Fatigue Scale, serologic markers, and other patient reported outcomes. In Type A cohort patients, clinical responses and pharmacologic activity will be assessed based on changes in serologic markers, SLEDAI-2K, FACIT Fatigue Scale. Pharmacodynamic markers, including markers that may allow future risk stratification, urinary ALCAM and CD6, will be examined in both cohort types. Results The study is ongoing. Six patients have been enrolled in Type A Cohort 1 (0.4 mg/kg dose) and completed both treatment and 4 weeks of post-treatment follow-up. The mean age was 59.5 (12.9) years, 100% were female; 67% were Hispanic/Latino; and 50% were White, and 50% were Black. Duration of SLE ranged from 3 years to 31 years. Concomitant medications for lupus included prednisone (83%, dose range 2.5 mg – 10 mg), methotrexate (33%), and anti-malarials (33%). Baseline SLEDAI-2K (mean 7.5 [2.2]) was based on findings of alopecia (83%); arthritis (67%); mucosal ulcers and rash (50% each); fever, increased dsDNA, and low complement (17% each). There were no adverse events. Additional data from this ongoing study will be presented. Conclusion Itolizumab, a monoclonal antibody blocking the CD6-ALCAM pathway, is a novel experimental treatment for LN. This is the first trial of itolizumab in patients with SLE and apLN. Data from the first cohort of patients suggest that the drug is safe and well-tolerated at a dose of 0.4 mg/kg over a 4-week treatment period. Additional cohorts of patients with SLE and apLN are currently being enrolled.

A Potential Therapeutic Target RNA-binding Protein, Arid5a for the Treatment of Inflammatory Disease Associated with Aberrant Cytokine Expression

2018 ◽  
Vol 24 (16) ◽  
pp. 1766-1771 ◽  
Author(s):  
Kazuya Masuda ◽  
Tadamitsu Kishimoto
Keyword(s):  
Gene Expression ◽  
T Cells ◽  
Severe Sepsis ◽  
Inflammatory Cytokines ◽  
Binding Proteins ◽  
Rna Binding ◽  
Cytokine Production ◽  
Rna Binding Proteins ◽  
Critical Role ◽  
Transcriptional Level

Background: Infection, tissue damage and aging can cause inflammation with high levels of inflammatory cytokines. Overproduction of inflammatory cytokines often leads to systemic inflammatory response syndrome (SIRS), severe sepsis, and septic shock. However, prominent therapeutic targets have not been found, although the incidence of sepsis is likely to increase annually. Our recent studies indicate that some RNA-binding proteins, which control gene expression of inflammatory cytokines at the post-transcriptional level, may play a critical role in inflammatory diseases such as sepsis. Results: 1) One of the RNA-binding proteins, AT-rich interactive domain-containing 5a (Arid5a) promotes cytokine production through control of mRNA half-lives of pro-inflammatory molecules such as IL-6, STAT3, T-bet, and OX40 in activated macrophages and T cells. Arid5a KO mice are refractory to endotoxin shock, bleomycininduced lung injury, and inflammatory autoimmune disease. 2) Chlorpromazine (CPZ), which is recognized as a psychotic drug, impairs post-transcriptional gene expression of Il6 in LPS-stimulated macrophages: CPZ inhibits the binding activity of Arid5a to the 3’UTR of Il6 mRNA, thereby destabilizing Il6 mRNA possibly through suppression of Arid5a expression. 3) CPZ has strong suppressive effects on cytokine production such as TNF-α in vivo. Mice with treatment of CPZ are resistant to lipopolysaccharide (LPS)-induced shock. Conclusion: Thus, Arid5a contributes to the activation of macrophages and T cells through positive control of mRNA half-lives of inflammatory cytokines and its related molecules, which might lead to cytokine storm. Interestingly, Arid5a was identified from an inhibitory effect of CPZ on IL-6 production in macrophages activated by LPS. Therefore, CPZ derivatives or Arid5a inhibitors may have a potential to suppress severe sepsis through control of post-transcriptional gene expression.

scholarly journals A Trypanosoma cruzi Zinc Finger protein that controls expression of epimastigote specific genes and affects metacyclogenesis

2020 ◽  
Author(s):  
Thais Silva Tavares ◽  
Fernanda Lins Brandão Mügge ◽  
Viviane Grazielle-Silva ◽  
Bruna Mattioly Valente ◽  
Wanessa Moreira Goes ◽  
...  
Keyword(s):  
Gene Expression ◽  
Trypanosoma Cruzi ◽  
Zinc Finger ◽  
Rna Binding ◽  
Environmental Changes ◽  
Zinc Finger Protein ◽  
Negative Regulator ◽  
Transcriptional Level ◽  
Control Of Gene Expression ◽  
Genes Encoding

SummaryTrypanosoma cruzi has three biochemically and morphologically distinct developmental stages that are programed to rapidly respond to environmental changes the parasite faces during its life cycle. Unlike other eukaryotes, Trypanosomatid genomes contain protein coding genes that are transcribed into polycistronic pre-mRNAs and control of gene expression relies on mechanisms acting at the post-transcriptional level. Transcriptome analyses comparing epimastigote, trypomastigote and intracellular amastigote stages revealed changes in gene expression that reflect the parasite adaptation to distinct environments. Several genes encoding RNA binding proteins (RBP), known to act as key post-transcriptional regulatory factors, were also differentially expressed. We characterized one T. cruzi RBP (TcZH3H12) that contains a zinc finger domain, and whose transcripts are upregulated in epimastigotes compared to trypomastigotes and amastigotes. TcZC3H12 knockout epimastigotes showed decreased growth rates and increased capacity to differentiate into metacyclic trypomastigotes. Comparative transcriptome analysis revealed a TcZC3H12-dependent expression of epimastigote specific genes encoding amino acid transporters and proteins associated with differentiation (PAD), among others. RNA immunoprecipitation assays showed that transcripts from the PAD family interact with TcZC3H12. Taken together, these findings suggest that TcZC3H12 positively regulates the expression of genes involved in epimastigote proliferation and also acts as a negative regulator of metacyclogenesis.

scholarly journals Induction of a cationic shift in IgG anti-DNA autoantibodies. Role of T helper cells with classical and novel phenotypes in three murine models of lupus nephritis.

1987 ◽  
Vol 165 (5) ◽  
pp. 1252-1268 ◽  
Author(s):  
S K Datta ◽  
H Patel ◽  
D Berry
Keyword(s):  
T Cells ◽  
B Cells ◽  
Lupus Nephritis ◽  
Lupus Erythematosus ◽  
Underlying Mechanism ◽  
Systemic Autoimmune Disease ◽  
Murine Models ◽  
Th Cells ◽  
Class B

We investigated the underlying mechanisms of systemic autoimmune disease in MRL-+/+, (NZB X NZW)F1, and (NZB X SWR)F1 mice, since these strains develop glomerulonephritis without the superimposition of any secondary lupus-accelerating genes. All three strains manifested a common immunoregulatory defect specific for the production of pathogenic anti-DNA autoantibodies that are of IgG class and cationic in charge. At or just before the age they began to develop lupus nephritis, spleen cells of the mice contained a subpopulation of Th cells that selectively induced their B cells in vitro to produce highly cationic IgG autoantibodies to both single-stranded DNA (ssDNA) and double-stranded DNA (dsDNA). By contrast, T cells from younger preautoimmune mice were incapable of providing this help. Moreover, only B cells of the older lupus mice could be induced to secrete cationic anti-DNA antibodies of IgG class. B cells of young lupus mice could not produce the cationic autoantibodies even with the help of T cells from the older mice, nor upon stimulation with mitogens. In the older lupus mice we found two sets of Th cells that spontaneously induced the cationic shift in autoantibodies; one set belonged to the classical Th category with L3T4+,Lyt-2- phenotype, whereas the other surprisingly belonged to a double-negative (L3T4-,Lyt-2-), Lyt-1+ subpopulation. The latter set of unusual Th cells were unexpected in these lupus mice since they lacked the lpr (lympho-proliferation) gene. Thus three apparently different murine models of systemic lupus erythematosus possess a common underlying mechanism specific for the spontaneous production of pathogenic anti-DNA autoantibodies.

The influence of obesity on hydroxychloroquine blood levels in lupus nephritis patients

Lupus ◽  
2021 ◽  
pp. 096120332098521
Author(s):  
Tatiana Pedrosa ◽  
Léonard de Vinci Kanda Kupa ◽  
Sandra Gofinet Pasoto ◽  
Nádia Emi Aikawa ◽  
Eduardo Ferreira Borba ◽  
...  
Keyword(s):  
Body Weight ◽  
Lupus Nephritis ◽  
Lupus Erythematosus ◽  
Blood Levels ◽  
Concomitant Treatment ◽  
Obese Patients ◽  
Maximum Daily Dose ◽  
Increased Risk ◽  
Daily Dose ◽  
The Impact

Introduction In 2016 the American Academy of Ophthalmology(2016-AAO) recommended a maximum daily HCQ use of 5.0 mg/kg real body weight(RBW) taking into consideration minimizing eye toxicity. Retinopathy in systemic lupus erythematosus(SLE) patients was recently associated with obesity and this condition is progressively more common in these patients. However, the impact of obesity in HCQ blood levels remains controversial. Objective To determine if the 2016-AAO recommendation based on RBW with and without maximum daily dose restriction results in adequate and safe blood levels in obese lupus nephritis(LN) patients. Methods A cross-sectional study was performed with 108 LN patients under the prescribed 2016-AAO dose for at least 3 months. LN patients were assessed for demographic characteristics, body mass index(BMI), disease parameters, HCQ dose, concomitant treatment and HCQ blood levels measured by liquid chromatography-tandem mass spectrometry. Obesity was defined as BMI ≥30kg/m2. Results Obesity was identified in 35/108(32%) LN patients. The calculation of HCQ daily dosage revealed that obese patients were under a lower prescribed daily dose according to the real body weight (RBW) [4.4(2.9-5.4) vs. 4.9(4-5.5)mg/Kg/day, p < 0.001] due to the maximum limit used. Regardless of that the median of HCQ blood levels was significantly higher in obese compared to non-obese patients (1562 ± 548.6 vs. 1208 ± 448.9 ng/mL, p = 0.002). Further analysis of patients under the 20016-AAO recommendation by RBW without the restriction of maximum daily dose confirmed that in spite of comparable daily dose in 14 obese patients and 61 non-obese patients [4.8 (4.5-5.4) vs. 5.0(4.5-5.5) mg/kg, p = 0.312], the median of HCQ blood levels was significantly higher in obese patients than in non-obese (1734 ± 457.3 vs. 1189 ± 449.4 ng/mL, p < 0.001). Conclusion Obese patients under the 2016-AAO prescribed dose of HCQ based on RBW with and without maximum daily dose restriction have a very high HCQ blood levels compared to non-obese patients, with a potential increased risk of ocular toxicity. The use of 2016-AAO dose of HCQ according to the ideal body weight for this group of patients should be considered.Clinicaltrials.gov #NCT0312243.

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