scholarly journals Bruton’s Tyrosine Kinase Inhibition Promotes Myelin Repair

2020 ◽  
Vol 5 (2) ◽  
pp. 123-133
Author(s):  
Elodie Martin ◽  
Marie-Stéphane Aigrot ◽  
Roland Grenningloh ◽  
Bruno Stankoff ◽  
Catherine Lubetzki ◽  
...  
Keyword(s):  
Tyrosine Kinase ◽  
Ex Vivo ◽  
Fold Increase ◽  
Experimental Models ◽  
Bruton’S Tyrosine Kinase ◽  
Bruton's Tyrosine Kinase ◽  
Myelin Repair ◽  
Before And After

Background: Microglia are the resident macrophages of the central nervous system (CNS). In multiple sclerosis (MS) and related experimental models, microglia have either a pro-inflammatory or a pro-regenerative/pro-remyelinating function. Inhibition of Bruton’s tyrosine kinase (BTK), a member of the Tec family of kinases, has been shown to block differentiation of pro-inflammatory macrophages in response to granulocyte–macrophage colony-stimulating factor in vitro. However, the role of BTK in the CNS is unknown. Methods: Our aim was to investigate the effect of BTK inhibition on myelin repair in ex vivo and in vivo experimental models of demyelination and remyelination. The remyelination effect of a BTK inhibitor (BTKi; BTKi-1) was then investigated in LPC-induced demyelinated cerebellar organotypic slice cultures and metronidazole-induced demyelinated Xenopus MBP-GFP-NTR transgenic tadpoles. Results: Cellular detection of BTK and its activated form BTK-phospho-Y223 (p-BTK) was determined by immunohistochemistry in organotypic cerebellar slice cultures, before and after lysophosphatidylcholine (LPC)-induced demyelination. A low BTK signal detected by immunolabeling under normal conditions in cerebellar slices was in sharp contrast to an 8.5-fold increase in the number of BTK-positive cells observed in LPC-demyelinated slice cultures. Under both conditions, approximately 75% of cells expressing BTK and p-BTK were microglia and 25% were astrocytes. Compared with spontaneous recovery, treatment of demyelinated slice cultures and MTZ-demyelinated transgenic tadpoles with BTKi resulted in at least a 1.7-fold improvement of remyelination. Conclusion: Our data demonstrate that BTK inhibition is a promising therapeutic strategy for myelin repair.

scholarly journals Silencing Bruton's tyrosine kinase in alveolar neutrophils protects mice from LPS/immune complex-induced acute lung injury

2014 ◽  
Vol 307 (6) ◽  
pp. L435-L448 ◽  
Author(s):  
Agnieszka Krupa ◽  
Marek Fol ◽  
Moshiur Rahman ◽  
Karen Y. Stokes ◽  
Jon M. Florence ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
Tyrosine Kinase ◽  
Immune Complex ◽  
Distress Syndrome ◽  
Bruton’S Tyrosine Kinase ◽  
Bruton's Tyrosine Kinase ◽  
Neutrophil Survival

Previous observations made by our laboratory indicate that Bruton's tyrosine kinase (Btk) may play an important role in the pathophysiology of local inflammation in acute lung injury (ALI)/acute respiratory distress syndrome (ARDS). We have shown that there is cross talk between FcγRIIa and TLR4 in alveolar neutrophils from patients with ALI/ARDS and that Btk mediates the molecular cooperation between these two receptors. To study the function of Btk in vivo we have developed a unique two-hit model of ALI: LPS/immune complex (IC)-induced ALI. Furthermore, we conjugated F(ab)2 fragments of anti-neutrophil antibodies (Ly6G1A8) with specific siRNA for Btk to silence Btk specifically in alveolar neutrophils. It should be stressed that we are the first group to perform noninvasive transfections of neutrophils, both in vitro and in vivo. Importantly, our present findings indicate that silencing Btk in alveolar neutrophils has a dramatic protective effect in mice with LPS/IC-induced ALI, and that Btk regulates neutrophil survival and clearance of apoptotic neutrophils in this model. In conclusion, we put forward a hypothesis that Btk-targeted neutrophil specific therapy is a valid goal of research geared toward restoring homeostasis in lungs of patients with ALI/ARDS.

scholarly journals Oral administration of Bruton's tyrosine kinase inhibitors impairs GPVI-mediated platelet function

2016 ◽  
Vol 310 (5) ◽  
pp. C373-C380 ◽  
Author(s):  
Rachel A. Rigg ◽  
Joseph E. Aslan ◽  
Laura D. Healy ◽  
Michael Wallisch ◽  
Marisa L. D. Thierheimer ◽  
...  
Keyword(s):  
Tyrosine Kinase ◽  
Platelet Activation ◽  
Platelet Function ◽  
Lymphocytic Leukemia ◽  
Bruton’S Tyrosine Kinase ◽  
Bruton's Tyrosine Kinase ◽  
Glycoprotein Vi ◽  
Activation Spreading

The Tec family kinase Bruton's tyrosine kinase (Btk) plays an important signaling role downstream of immunoreceptor tyrosine-based activation motifs in hematopoietic cells. Mutations in Btk are involved in impaired B-cell maturation in X-linked agammaglobulinemia, and Btk has been investigated for its role in platelet activation via activation of the effector protein phospholipase Cγ2 downstream of the platelet membrane glycoprotein VI (GPVI). Because of its role in hematopoietic cell signaling, Btk has become a target in the treatment of chronic lymphocytic leukemia and mantle cell lymphoma; the covalent Btk inhibitor ibrutinib was recently approved by the US Food and Drug Administration for treatment of these conditions. Antihemostatic events have been reported in some patients taking ibrutinib, although the mechanism of these events remains unknown. We sought to determine the effects of Btk inhibition on platelet function in a series of in vitro studies of platelet activation, spreading, and aggregation. Our results show that irreversible inhibition of Btk with two ibrutinib analogs in vitro decreased human platelet activation, phosphorylation of Btk, P-selectin exposure, spreading on fibrinogen, and aggregation under shear flow conditions. Short-term studies of ibrutinib analogs administered in vivo also showed abrogation of platelet aggregation in vitro, but without measurable effects on plasma clotting times or on bleeding in vivo. Taken together, our results suggest that inhibition of Btk significantly decreased GPVI-mediated platelet activation, spreading, and aggregation in vitro; however, prolonged bleeding was not observed in a model of bleeding.

scholarly journals Targeting Bruton’s Tyrosine Kinase in Inflammatory and Autoimmune Pathologies

2021 ◽  
Vol 9 ◽  
Author(s):  
Stefan F. H. Neys ◽  
Rudi W. Hendriks ◽  
Odilia B. J. Corneth
Keyword(s):  
B Cells ◽  
Tyrosine Kinase ◽  
B Cell ◽  
Critical Role ◽  
Myeloid Cells ◽  
Systemic Autoimmune Disease ◽  
Bruton’S Tyrosine Kinase ◽  
Bruton's Tyrosine Kinase

Bruton’s tyrosine kinase (BTK) was discovered due to its importance in B cell development, and it has a critical role in signal transduction downstream of the B cell receptor (BCR). Targeting of BTK with small molecule inhibitors has proven to be efficacious in several B cell malignancies. Interestingly, recent studies reveal increased BTK protein expression in circulating resting B cells of patients with systemic autoimmune disease (AID) compared with healthy controls. Moreover, BTK phosphorylation following BCR stimulation in vitro was enhanced. In addition to its role in BCR signaling, BTK is involved in many other pathways, including pattern recognition, Fc, and chemokine receptor signaling in B cells and myeloid cells. This broad involvement in several immunological pathways provides a rationale for the targeting of BTK in the context of inflammatory and systemic AID. Accordingly, numerous in vitro and in vivo preclinical studies support the potential of BTK targeting in these conditions. Efficacy of BTK inhibitors in various inflammatory and AID has been demonstrated or is currently evaluated in clinical trials. In addition, very recent reports suggest that BTK inhibition may be effective as immunosuppressive therapy to diminish pulmonary hyperinflammation in coronavirus disease 2019 (COVID-19). Here, we review BTK’s function in key signaling pathways in B cells and myeloid cells. Further, we discuss recent advances in targeting BTK in inflammatory and autoimmune pathologies.

scholarly journals Bruton's Tyrosine Kinase Is Required for Activation of Iκb Kinase and Nuclear Factor κb in Response to B Cell Receptor Engagement

2000 ◽  
Vol 191 (10) ◽  
pp. 1745-1754 ◽  
Author(s):  
James B. Petro ◽  
S.M. Jamshedur Rahman ◽  
Dean W. Ballard ◽  
Wasif N. Khan
Keyword(s):  
Tyrosine Kinase ◽  
B Cell ◽  
Cell Cycle Progression ◽  
Coupling Mechanism ◽  
Bruton’S Tyrosine Kinase ◽  
Nuclear Factor ◽  
Bruton's Tyrosine Kinase ◽  
Iκb Kinase

Mutations in the gene encoding Bruton's tyrosine kinase (btk) cause the B cell deficiency diseases X-linked agammaglobulinemia (XLA) in humans and X-linked immunodeficiency (xid) in mice. In vivo and in vitro studies indicate that the BTK protein is essential for B cell survival, cell cycle progression, and proliferation in response to B cell antigen receptor (BCR) stimulation. BCR stimulation leads to the activation of transcription factor nuclear factor (NF)-κB, which in turn regulates genes controlling B cell growth. We now demonstrate that a null mutation in btk known to cause the xid phenotype prevents BCR-induced activation of NF-κB. This defect can be rescued by reconstitution with wild-type BTK. This mutation also interferes with BCR-directed activation of IκB kinase (IKK), which normally targets the NF-κB inhibitor IκBα for degradation. Taken together, these findings indicate that BTK couples IKK and NF-κB to the BCR. Interference with this coupling mechanism may contribute to the B cell deficiencies observed in XLA and xid.

scholarly journals Ocular Toxoplasmosis: Mechanisms of Retinal Infection and Experimental Models

Parasitologia ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 50-60
Author(s):  
Veronica Rodriguez Fernandez ◽  
Giovanni Casini ◽  
Fabrizio Bruschi
Keyword(s):  
Ex Vivo ◽  
Cell Damage ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Treatment Strategies ◽  
Experimental Models ◽  
Ocular Toxoplasmosis ◽  
Cell Infection

Ocular toxoplasmosis (OT) is caused by the parasite Toxoplasma gondii and affects many individuals throughout the world. Infection may occur through congenital or acquired routes. The parasites enter the blood circulation and reach both the retina and the retinal pigment epithelium, where they may cause cell damage and cell death. Different routes of access are used by T. gondii to reach the retina through the retinal endothelium: by transmission inside leukocytes, as free parasites through a paracellular route, or after endothelial cell infection. A main feature of OT is the induction of an important inflammatory state, and the course of infection has been shown to be influenced by the host immunogenetics. On the other hand, there is evidence that the T. gondii phenotype also has an impact on the distribution of the pathology in different areas. Although considerable knowledge has been acquired on OT, a deeper knowledge of its mechanisms is necessary to provide new, more targeted treatment strategies. In particular, in addition to in vitro and in vivo experimental models, organotypic, ex vivo retinal explants may be useful in this direction.

scholarly journals Augmented expansion of Treg cells from healthy and autoimmune subjects via adult progenitor cell co-culture

2020 ◽  
Author(s):  
JL Reading ◽  
VD Roobrouck ◽  
CM Hull ◽  
PD Becker ◽  
J Beyens ◽  
...  
Keyword(s):  
T Cell ◽  
Treg Cell ◽  
Regulatory T Cell ◽  
Cellular Therapy ◽  
Ex Vivo ◽  
Fold Increase ◽  
Adoptive Cellular Therapy ◽  
T Cell Therapy

AbstractRecent clinical experience has demonstrated that adoptive regulatory T cell therapy is a safe and feasible strategy to suppress immunopathology via induction of host tolerance to allo- and autoantigens. However, clinical trials continue to be compromised due to an inability to manufacture a sufficient Treg cell dose. Multipotent adult progenitor cells (MAPCⓇ) promote regulatory T cell differentiation in vitro, suggesting they may be repurposed to enhance ex vivo expansion of Tregs for adoptive cellular therapy. Here, we use a GMP compatible Treg expansion platform to demonstrate that MAPC cell-co-cultured Tregs (MulTreg) exhibit a log-fold increase in yield across two independent cohorts, reducing time to target dose by an average of 30%. Enhanced expansion is linked with a distinct Treg cell-intrinsic transcriptional program, characterized by diminished levels of core exhaustion (BATF, ID2, PRDM1, LAYN, DUSP1), and quiescence (TOB1, TSC22D3) related genes, coupled to elevated expression of cell-cycle and proliferation loci (MKI67, CDK1, AURKA, AURKB). In addition, MulTreg display a unique gut homing (CCR7lo β7hi) phenotype and importantly, are more readily expanded from patients with autoimmune disease compared to matched Treg lines, suggesting clinical utility in gut and/or Th1-driven pathology associated with autoimmunity or transplantation. Relative to expanded Tregs, MulTreg retain equivalent and robust purity, FoxP3 TSDR demethylation, nominal effector cytokine production and potent suppression of Th1-driven antigen specific and polyclonal responses in vitro and xeno graft vs host disease (xGvHD) in vivo. These data support the use of MAPC cell co-culture in adoptive Treg therapy platforms as a means to rescue expansion failure and reduce the time required to manufacture a stable, potently suppressive product.

Intermittent, Repetitive Corticosteroid-Induced Upregulation of Platelet Levels After Adenovirus-Mediated Transfer to the Liver of a Chimeric Glucocorticoid-Responsive Promoter Controlling the Thrombopoietin cDNA

Blood ◽  
1998 ◽  
Vol 92 (3) ◽  
pp. 822-833 ◽  
Author(s):  
Ko Narumi ◽  
Motoyoshi Suzuki ◽  
Wenru Song ◽  
Malcolm A.S. Moore ◽  
Ronald G. Crystal
Keyword(s):  
Clinical Medicine ◽  
Intraperitoneal Administration ◽  
Fold Increase ◽  
Inducible Promoter ◽  
Pharmacologic Agent ◽  
Before And After ◽  
American Society ◽  
Pharmacologic Agents

Abstract For many in vivo gene therapy clinical applications, it is desirable to control the expression of the transferred transgene using pharmacologic agents. To evaluate the feasibility of accomplishing this using corticosteroids, pharmacologic agents widely used in clinical medicine, we constructed replication deficient adenoviral (Ad) vectors containing an expression cassette with a chimeric promoter comprised of five glucocorticoid response elements (GRE) and the chloramphenicol acetyltransferase reporter gene (AdGRE.CAT) or the murine thrombopoietin cDNA (AdGRE.mTPO). In vitro studies showed the vectors functioned as expected, with marked glucocorticoid-induced upregulation of the CAT or mTPO transgenes. To evaluate the inducibility of the GRE promoter in vivo, the AdGRE.CAT vector was administered intravenously to C57B1/6 mice, and CAT activity was quantified in liver before and after intraperitoneal administration of dexamethasone. The GRE promoter activity was dependent on the dexamethasone dose, with a 100-fold increase in CAT expression with 50 μg dexamethasone, similar to the levels observed in vivo with the Rous sarcoma virus long terminal repeat constitutive promoter. After dexamethasone administration, maximum CAT activity was observed at day 2, with a slow decline to baseline levels by 2 weeks. Based on these observations, we hypothesized that a single administration of an Ad vector-mediated transfer of the chimeric GRE inducible promoter driving the mTPO cDNA would enable repetitive administration of corticosteroids to repetitively upregulate platelet levels for 1 to 2 weeks. The data show that this occurs, with dexamethasone administration every 3 weeks associated with 1-week elevations (at each 3-week interval) of serum mTPO levels, megakaryocyte numbers in bone marrow, and platelet levels fourfold to sixfold over baseline. Thus, with the appropriate promoter, it is possible to use a commonly used pharmacologic agent to upregulate the expression of a newly transferred gene on demand. © 1998 by The American Society of Hematology.

Abstract 317: Vecabrutinib inhibits C481 mutated Bruton's tyrosine kinase and its downstream signaling in vitro

2019 ◽  
Author(s):  
Burcu Aslan ◽  
Mikhila Mahendra ◽  
Michael D Peoples ◽  
Joe R. Marszalek ◽  
Christopher P Vellano ◽  
...  
Keyword(s):  
Tyrosine Kinase ◽  
Bruton’S Tyrosine Kinase ◽  
Bruton's Tyrosine Kinase ◽  
Downstream Signaling

scholarly journals The Diverse Potential of Gluten from Different Durum Wheat Varieties in Triggering Celiac Disease: A Multilevel In Vitro, Ex Vivo and In Vivo Approach

Nutrients ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3566
Author(s):  
Federica Gaiani ◽  
Sara Graziano ◽  
Fatma Boukid ◽  
Barbara Prandi ◽  
Lorena Bottarelli ◽  
...  
Keyword(s):  
Immune Response ◽  
Celiac Disease ◽  
Durum Wheat ◽  
Ex Vivo ◽  
Diet Group ◽  
Control Group ◽  
Wheat Varieties ◽  
Before And After

The reasons behind the increasing prevalence of celiac disease (CD) worldwide are still not fully understood. This study adopted a multilevel approach (in vitro, ex vivo, in vivo) to assess the potential of gluten from different wheat varieties in triggering CD. Peptides triggering CD were identified and quantified in mixtures generated from simulated gastrointestinal digestion of wheat varieties (n = 82). Multivariate statistics enabled the discrimination of varieties generating low impact on CD (e.g., Saragolla) and high impact (e.g., Cappelli). Enrolled subjects (n = 46) were: 19 healthy subjects included in the control group; 27 celiac patients enrolled for the in vivo phase. Celiacs were divided into a gluten-free diet group (CD-GFD), and a GFD with Saragolla-based pasta group (CD-Sar). The diet was followed for 3 months. Data were compared between CD-Sar and CD-GFD before and after the experimental diet, demonstrating a limited ability of Saragolla to trigger immunity, although not comparable to a GFD. Ex vivo studies showed that Saragolla and Cappelli activated immune responses, although with great variability among patients. The diverse potential of durum wheat varieties in triggering CD immune response was demonstrated. Saragolla is not indicated for celiacs, yet it has a limited potential to trigger adverse immune response.

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