scholarly journals Triptolide Modulates the Expression of Inflammation-Associated lncRNA-PACER and lincRNA-p21 in Mycobacterium tuberculosis–Infected Monocyte-Derived Macrophages

2021 ◽  
Vol 12 ◽  
Author(s):  
Ousman Tamgue ◽  
Julius Ebua Chia ◽  
Frank Brombacher
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Target Genes ◽  
Cell Function ◽  
Immune Cell ◽  
Biological Activities ◽  
Target Cells ◽  
Dependent Manner ◽  
Direct Targeting ◽  
Non Coding Rnas ◽  
Alamarblue Assay

Triptolide is a diterpene triepoxide, which performs its biological activities via mechanisms including induction of apoptosis, targeting of pro-inflammatory cytokines, and reshaping of the epigenetic landscape of target cells. However, the targeting of long non-coding RNAs (lncRNAs) by triptolide has not yet been investigated, despite their emerging roles as key epigenetic regulators of inflammation and immune cell function during Mycobacterium tuberculosis (Mtb) infection. Hence, we investigated whether triptolide targets inflammation-associated lncRNA-PACER and lincRNA-p21 and how this targeting associates with Mtb killing within monocyte-derived macrophages (MDMs).Using RT-qPCR, we found that triptolide induced the expression of lincRNA-p21 but inhibited the expression of lncRNA-PACER in resting MDMs in a dose- and time-dependent manner. Moreover, Mtb infection induced the expression of lincRNA-p21 and lncRNA-PACER, and exposure to triptolide before or after Mtb infection led to further increase of Mtb-induced expression of these lncRNAs in MDMs. We further found that contrary to lncRNA-PACER, triptolide time- and dose-dependently upregulated Ptgs-2, which is a proximal gene regulated by lncRNA-PACER. Also, low-concentration triptolide inhibited the expression of cytokine IL-6, a known target of lincRNA-p21. Mtb infection induced the expression of IL-6 and Ptgs-2, and triptolide treatment further increased IL-6 but decreased Ptgs-2 expression in Mtb-infected MDMs. The inverse relation between the expression of these lncRNAs and their target genes is concordant with the conception that these lncRNAs mediate, at least partially, the cytotoxic and/or anti-inflammatory activities of triptolide in both resting and activated MDMs. Using the CFU count method, we found that triptolide decreased the intracellular growth of Mtb HN878. The alamarBlue assay showed that this decreased Mtb HN878 growth was not as a result of direct targeting of Mtb HN878 by triptolide, but rather evoking MDMs’ intracellular killing mechanisms which we speculate could include triptolide-induced enhancement of MDMs’ effector killing functions mediated by lncRNA-PACER and lincRNA-p21. Altogether, these results provide proof of the modulation of lncRNA-PACER and lincRNA-p21 expression by triptolide, and a possible link between these lncRNAs, the enhancement of MDMs’ effector killing functions and the intracellular Mtb-killing activities of triptolide. These findings prompt for further investigation of the precise contribution of these lncRNAs to triptolide-induced activities in MDMs.

scholarly journals Neurons Are Host Cells for Mycobacterium tuberculosis

2014 ◽  
Vol 82 (5) ◽  
pp. 1880-1890 ◽  
Author(s):  
Philippa J. Randall ◽  
Nai-Jen Hsu ◽  
Dirk Lang ◽  
Susan Cooper ◽  
Boipelo Sebesho ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Mycobacterium Tuberculosis ◽  
Host Cells ◽  
Productive Infection ◽  
Target Cells ◽  
Dependent Manner ◽  
Content Type ◽  
The Central Nervous System

ABSTRACTMycobacterium tuberculosisinfection of the central nervous system is thought to be initiated once the bacilli have breached the blood brain barrier and are phagocytosed, primarily by microglial cells. In this study, the interactions ofM. tuberculosiswith neuronsin vitroandin vivowere investigated. The data obtained demonstrate that neurons can act as host cells forM. tuberculosis.M. tuberculosisbacilli were internalized by murine neuronal cultured cells in a time-dependent manner after exposure, with superior uptake by HT22 cells compared to Neuro-2a cells (17.7% versus 9.8%). Internalization ofM. tuberculosisbacilli by human SK-N-SH cultured neurons suggested the clinical relevance of the findings. Moreover, primary murine hippocampus-derived neuronal cultures could similarly internalizeM. tuberculosis. InternalizedM. tuberculosisbacilli represented a productive infection with retention of bacterial viability and replicative potential, increasing 2- to 4-fold within 48 h.M. tuberculosisbacillus infection of neurons was confirmedin vivoin the brains of C57BL/6 mice after intracerebral challenge. This study, therefore, demonstrates neurons as potential new target cells forM. tuberculosiswithin the central nervous system.

scholarly journals Glucose Triggers ATP Secretion from Bacteria in a Growth-Phase-Dependent Manner

2013 ◽  
Vol 79 (7) ◽  
pp. 2328-2335 ◽  
Author(s):  
Ippei Hironaka ◽  
Tadayuki Iwase ◽  
Shinya Sugimoto ◽  
Ken-ichi Okuda ◽  
Akiko Tajima ◽  
...  
Keyword(s):  
Stationary Phase ◽  
Growth Phase ◽  
Cell Function ◽  
Immune Cell ◽  
Dependent Manner ◽  
T Helper 17 ◽  
Content Type ◽  
Cell Functions ◽  
Atp Secretion ◽  
Enterococcus Gallinarum

ABSTRACTATP modulates immune cell functions, and ATP derived from gut commensal bacteria promotes the differentiation of T helper 17 (Th17) cells in the intestinal lamina propria. We recently reported thatEnterococcus gallinarum, isolated from mice and humans, secretes ATP. We have since found and characterized several ATP-secreting bacteria. Of the tested enterococci,Enterococcus mundtiisecreted the greatest amount of ATP (>2 μM/108cells) after overnight culture. Glucose, not amino acids and vitamins, was essential for ATP secretion fromE. mundtii. Analyses of energy-deprived cells demonstrated that glycolysis is the most important pathway for bacterial ATP secretion. Furthermore, exponential-phaseE. mundtiiandEnterococcus faecaliscells secrete ATP more efficiently than stationary-phase cells. Other bacteria, includingPseudomonas aeruginosa,Escherichia coli, andStaphylococcus aureus, also secrete ATP in exponential but not stationary phase. These results suggest that various gut bacteria, including commensals and pathogens, might secrete ATP at any growth phase and modulate immune cell function.

scholarly journals Molecular Mechanisms of Leukocyte Migration and Its Potential Targeting—Lessons Learned From MKL1/SRF-Related Primary Immunodeficiency Diseases

2021 ◽  
Vol 12 ◽  
Author(s):  
Evelien G. G. Sprenkeler ◽  
Carla Guenther ◽  
Imrul Faisal ◽  
Taco W. Kuijpers ◽  
Susanna C. Fagerholm
Keyword(s):  
Immune System ◽  
Molecular Mechanisms ◽  
Target Genes ◽  
Serum Response Factor ◽  
Cell Function ◽  
Immune Cell ◽  
Leukocyte Adhesion ◽  
Adaptive Immune System ◽  
Lessons Learned ◽  
Megakaryoblastic Leukemia

Megakaryoblastic leukemia 1 (MKL1) deficiency is one of the most recently discovered primary immunodeficiencies (PIDs) caused by cytoskeletal abnormalities. These immunological “actinopathies” primarily affect hematopoietic cells, resulting in defects in both the innate immune system (phagocyte defects) and adaptive immune system (T-cell and B-cell defects). MKL1 is a transcriptional coactivator that operates together with serum response factor (SRF) to regulate gene transcription. The MKL/SRF pathway has been originally described to have important functions in actin regulation in cells. Recent results indicate that MKL1 also has very important roles in immune cells, and that MKL1 deficiency results in an immunodeficiency affecting the migration and function of primarily myeloid cells such as neutrophils. Interestingly, several actinopathies are caused by mutations in genes which are recognized MKL(1/2)-dependent SRF-target genes, namely ACTB, WIPF1, WDR1, and MSN. Here we summarize these and related (ARPC1B) actinopathies and their effects on immune cell function, especially focusing on their effects on leukocyte adhesion and migration. Furthermore, we summarize recent therapeutic efforts targeting the MKL/SRF pathway in disease.

scholarly journals Global transcriptome analysis reveals partial estrogen-like effects of karanjin in MCF-7 breast cancer cells

2021 ◽  
Author(s):  
Gaurav Bhatt ◽  
Akshita Gupta ◽  
Latha Rangan ◽  
Anil Mukund Limaye
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Target Genes ◽  
Biological Activities ◽  
Biological Effects ◽  
Dependent Manner ◽  
Cell Type ◽  
Concentration Dependent Manner ◽  
Mcf 7

Karanjin, an abundantly occurring furanoflavonoid in edible and non-edible legumes, exerts diverse biological effects in vivo, and in vitro. Its potential as an anticancer agent is also gaining traction following recent demonstrations of its anti-proliferative, cell cycle inhibitory, and pro-apoptotic effects. However, the universality of its anticancer potential is yet to be scrutinized, particularly so because flavonoids can act as selective estrogen receptor modulators (SERMs). Even the genomic correlates of its biological activities are yet to be examined in hormone responsive cells. This paper presents the early and direct transcriptomic footprint of 10 μM karanjin in MCF-7 breast cancer cells, using next generation sequencing technology (RNA-seq). We show that karanjin-modulated gene-expression repertoire is enriched in several hallmark gene sets, which include early estrogen-response, and G2/M checkpoint genes. Genes modulated by karanjin overlapped with those modulated by 1 nM 17β-estradiol (E2), or 1 μM tamoxifen. Karanjin altered the expression of selected estrogen-regulated genes in a cell-type, and concentration dependent manner. It downmodulated the expression of ERα protein in MCF-7 cells. Furthermore, ERα knockdown negatively impacted karanjins ability to modulate the expression of selected E2 target genes. Our data suggest that karanjin exerts its effects on ERα-positive breast cancer cells, at least in part, via ERα. The apparent SERM-like effects of karanjin pose a caveat to the anticancer potential of karanjin. In-depth studies on cell-type and concentration-dependent effects of karanjin may bring out its true potential in endocrine therapies.

scholarly journals Immune deconvolution and temporal mapping identifies stromal targets and developmental intervals for abrogating murine low-grade optic glioma formation

2021 ◽  
Author(s):  
Amanda de Andrade Costa ◽  
Jit Chatterjee ◽  
Olivia Cobb ◽  
Elizabeth Cordell ◽  
Astoria Chao ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Function ◽  
Immune Cell ◽  
Tumor Formation ◽  
Optic Glioma ◽  
Low Grade ◽  
Dependent Manner ◽  
Cancer Predisposition Syndrome

Abstract Background Brain tumor formation and progression are dictated by cooperative interactions between neoplastic and non-neoplastic cells. This stromal dependence is nicely illustrated by tumors arising in the Neurofibromatosis type 1 (NF1) cancer predisposition syndrome, where children develop low-grade optic pathway gliomas (OPGs). Using several authenticated Nf1-OPG murine models, we previously demonstrated that murine Nf1-OPG growth is regulated by T cell function and microglia Ccl5 production, such that their inhibition reduces tumor proliferation in vivo. While these interactions are critical for established Nf1-OPG tumor growth, their importance in tumor formation has not been explored. Methods A combination of bulk and single cell RNA mouse optic nerve sequencing, immunohistochemistry, T cell assays, and pharmacologic and antibody-mediated inhibition methods were used in these experiments. Results We show that T cells and microglia are the main non-neoplastic immune cell populations in both murine and human LGGs. Moreover, we demonstrate that CD8 + T cells, the predominant LGG-infiltrating lymphocyte population, are selectively recruited through increased Ccl2 receptor (Ccr4) expression in CD8 +, but not CD4 +, T cells, in a NF1/RAS-dependent manner. Finally, we identify the times during gliomagenesis when microglia Ccl5 production (3-6 weeks of age) and Ccl2-mediated T cell infiltration (7-10 weeks of age) occur, such that temporally-restricted Ccl2 or Ccl5 inhibition abrogates tumor formation >3.5 months following the cessation of treatment. Conclusions Collectively, these findings provide proof-of-concept demonstrations that targeting stromal support during early gliomagenesis durably blocks murine LGG formation.

Phorbol ester-induced U-937 differentiation: effects on integrin α 5 gene transcription

2000 ◽  
Vol 278 (4) ◽  
pp. L703-L712 ◽  
Author(s):  
Bonnie K. Boles ◽  
Jeffrey Ritzenthaler ◽  
Thomas Birkenmeier ◽  
Jesse Roman
Keyword(s):  
Lung Injury ◽  
Cell Function ◽  
Immune Cell ◽  
Biological Effects ◽  
Surface Expression ◽  
Tumor Promoter ◽  
Dependent Manner ◽  
Activator Protein 1 ◽  
Monocytic Cell ◽  
Promoter Sequences

Lung injury is accompanied by increased deposition of fibronectin (FN) matrices. Activated monocytic cells recruited to sites of lung injury express integrin receptors for FN that mediate their interaction with this matrix. One such integrin, α5β1, mediates many of the biological effects of FN, and its expression may be important for immune cell function at sites of lung injury. Herein, we examine the expression of α5β1 in response to the tumor promoter phorbol 12-myristate 13-acetate (PMA) in the human promonocytic cell line U-937. We demonstrate that PMA enhanced the adherence of U-937 cells to FN by increasing the expression of both the α5- and β1-subunit mRNAs and the surface expression of the protein. In U-937 cells transfected with an α 5 promoter-reporter gene, we found that PMA induced the transcription of the α 5 gene by acting on very specific promoter sequences other than activator protein-1 in a protein kinase C-dependent manner. Lipopolysaccharide had a similar effect. Modulation of α5β1 expression may be important for regulation of monocytic cell function in lung inflammation after injury.

scholarly journals Plasma kallikrein modulates immune cell trafficking during neuroinflammation via PAR2 and bradykinin release

2018 ◽  
Vol 116 (1) ◽  
pp. 271-276 ◽  
Author(s):  
Kerstin Göbel ◽  
Chloi-Magdalini Asaridou ◽  
Monika Merker ◽  
Susann Eichler ◽  
Alexander M. Herrmann ◽  
...  
Keyword(s):  
Adhesion Molecule ◽  
Cell Function ◽  
Immune Cell ◽  
Cellular Adhesion ◽  
Coagulation System ◽  
Intercellular Adhesion Molecule ◽  
Plasma Kallikrein ◽  
Dependent Manner ◽  
Cns Inflammation ◽  
Endothelial Cell Function

Blood–brain barrier (BBB) disruption and transendothelial trafficking of immune cells into the central nervous system (CNS) are pathophysiological hallmarks of neuroinflammatory disorders like multiple sclerosis (MS). Recent evidence suggests that the kallikrein-kinin and coagulation system might participate in this process. Here, we identify plasma kallikrein (KK) as a specific direct modulator of BBB integrity. Levels of plasma prekallikrein (PK), the precursor of KK, were markedly enhanced in active CNS lesions of MS patients. Deficiency or pharmacologic blockade of PK renders mice less susceptible to experimental autoimmune encephalomyelitis (a model of MS) and is accompanied by a remarkable reduction of BBB disruption and CNS inflammation. In vitro analysis revealed that KK modulates endothelial cell function in a protease-activated receptor-2–dependent manner, leading to an up-regulation of the cellular adhesion molecules Intercellular Adhesion Molecule 1 and Vascular Cell Adhesion Molecule 1, thereby amplifying leukocyte trafficking. Our study demonstrates that PK is an important direct regulator of BBB integrity as a result of its protease function. Therefore, KK inhibition can decrease BBB damage and cell invasion during neuroinflammation and may offer a strategy for the treatment of MS.

587 Tumor-activated Fc-engineered anti-CTLA-4 monoclonal antibody, XTX101, demonstrates tumor-selective PD and efficacy in preclinical models

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A622-A622
Author(s):  
Kurt Jenkins ◽  
Parker Johnson ◽  
Minjie Zhang ◽  
Wilson Guzman ◽  
Ugur Eskiocak ◽  
...  
Keyword(s):  
T Cell ◽  
Cell Activation ◽  
Cell Function ◽  
Immune Cell ◽  
Tumor Regression ◽  
Dependent Manner ◽  
Human Solid Tumor ◽  
Covalently Linked ◽  
Tumor Selective

BackgroundThe clinical benefit of CTLA-4 blockade to cancer patients has been well established. However, the promising antitumor activity shown by anti-CTLA-4 monoclonal antibodies (mAb) has been limited by the occurrence of immune-mediated adverse reactions, especially when CTLA-4 inhibition is used in combination with anti-PD-1 therapy. These dose-limiting toxicities restrict the therapeutic use of CTLA-4 blockade. To overcome these limitations, we have developed a potent anti-CTLA-4 antibody that is selectively active in the tumor microenvironment (TME). This antibody is engineered with an Fc region for enhanced FcγR binding and peptides that mask antigen-binding regions. The masking peptides are designed to be selectively cleaved and released by proteases that are more active in the TME, resulting in restoration of full activity of the antibody in the TME.MethodsA novel, fully-humanized anti-huCTLA-4 mAb was shown to bind human CTLA-4 with improved affinity compared to ipilimumab, as measured by SPR. Engineering of the Fc region enhanced FcγR binding and ADCC function. In addition, CDR-binding peptides identified by phage display were covalently linked to the antibody using a protease-sensitive polypeptide linker. This engineered anti-CTLA-4 antibody (XTX101) showed protease-dependent binding to CTLA-4 both with recombinant and tumor tissue derived proteases.ResultsXTX101 demonstrated a 100-fold reduction in binding to human CTLA-4 by ELISA, compared to the non-masked antibody. Incubation with recombinant protease led to cleavage and release of the masking peptides and restored full binding to CTLA-4. Similarly, in vitro ADCC activity was impaired by masking and restored in a protease-dependent manner. SEB-stimulated human PMBCs were minimally responsive in vitro to XTX101, whereas PBMCs treated with proteolytically-activated XTX101 exhibited robust activation of T cell function. In human CTLA-4 knock-in mice with syngeneic MB49 tumors, XTX101 treatment led to complete tumor regression, enhanced CD8+ T cell proliferation, and depletion of tumor Tregs in the TME. By contrast, XTX101 had minimal pharmacodynamic effects in the periphery. In addition, XTX101 is effectively activated in culture supernatants from human solid tumor explants obtained from a broad range of tumor types.ConclusionsXTX101 is a tumor-selective anti-CTLA-4 mAb capable of: 1) effective CTLA-4 blockade, 2) depletion of intratumoral Tregs through enhanced antibody-dependent cellular cytotoxicity (ADCC) function, 3) minimization of systemic immune cell activation, and 4) potent anti-tumor activity. These pre-clinical data support the further evaluation of XTX101 in clinical studies.

scholarly journals Vav1 Is a Component of Transcriptionally Active Complexes

2002 ◽  
Vol 195 (9) ◽  
pp. 1115-1127 ◽  
Author(s):  
Martin Houlard ◽  
Ramachandran Arudchandran ◽  
Fabienne Regnier-Ricard ◽  
Antonia Germani ◽  
Sylvie Gisselbrecht ◽  
...  
Keyword(s):  
Nuclear Localization ◽  
Cell Function ◽  
Immune Cell ◽  
Critical Role ◽  
Sh3 Domain ◽  
Nuclear Localization Sequence ◽  
Pleckstrin Homology Domain ◽  
Dependent Manner ◽  
Nuclear Factor ◽  
Activated T Cells

The importance of the hematopoietic protooncogene Vav1 in immune cell function is widely recognized, although its regulatory mechanisms are not completely understood. Here, we examined whether Vav1 has a nuclear function, as past studies have reported its nuclear localization. Our findings provide a definitive demonstration of Vav1 nuclear localization in a receptor stimulation–dependent manner and reveal a critical role for the COOH-terminal Src homology 3 (SH3) domain and a nuclear localization sequence within the pleckstrin homology domain. Analysis of DNA-bound transcription factor complexes revealed nuclear Vav1 as an integral component of transcriptionally active nuclear factor of activated T cells (NFAT)- and nuclear factor (NF)κB-like complexes, and the COOH-terminal SH3 domain as being critical in their formation. Thus, we describe a novel nuclear role for Vav1 as a component and facilitator of NFAT and NFκB-like transcriptional activity.

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