scholarly journals CRL4-DCAF12 Ubiquitin Ligase Controls MOV10 RNA Helicase during Spermatogenesis and T Cell Activation

2021 ◽  
Vol 22 (10) ◽  
pp. 5394
Author(s):  
Tomas Lidak ◽  
Nikol Baloghova ◽  
Vladimir Korinek ◽  
Radislav Sedlacek ◽  
Jana Balounova ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Activation ◽  
Ubiquitin Ligase ◽  
Cell Activation ◽  
Rna Helicase ◽  
Dependent Manner ◽  
Amino Acid Residues ◽  
Risc Complex ◽  
Wide Range

Multisubunit cullin-RING ubiquitin ligase 4 (CRL4)-DCAF12 recognizes the C-terminal degron containing acidic amino acid residues. However, its physiological roles and substrates are largely unknown. Purification of CRL4-DCAF12 complexes revealed a wide range of potential substrates, including MOV10, an “ancient” RNA-induced silencing complex (RISC) complex RNA helicase. We show that DCAF12 controls the MOV10 protein level via its C-terminal motif in a proteasome- and CRL-dependent manner. Next, we generated Dcaf12 knockout mice and demonstrated that the DCAF12-mediated degradation of MOV10 is conserved in mice and humans. Detailed analysis of Dcaf12-deficient mice revealed that their testes produce fewer mature sperms, phenotype accompanied by elevated MOV10 and imbalance in meiotic markers SCP3 and γ-H2AX. Additionally, the percentages of splenic CD4+ T and natural killer T (NKT) cell populations were significantly altered. In vitro, activated Dcaf12-deficient T cells displayed inappropriately stabilized MOV10 and increased levels of activated caspases. In summary, we identified MOV10 as a novel substrate of CRL4-DCAF12 and demonstrated the biological relevance of the DCAF12-MOV10 pathway in spermatogenesis and T cell activation.

scholarly journals Gastric Helicobacter Infection Inhibits Development of Oral Tolerance to Food Antigens in Mice

2003 ◽  
Vol 71 (9) ◽  
pp. 5219-5224 ◽  
Author(s):  
Tamara Matysiak-Budnik ◽  
Guillaume van Niel ◽  
Francis Mégraud ◽  
Kathryn Mayo ◽  
Claudia Bevilacqua ◽  
...  
Keyword(s):  
T Cell ◽  
Antigen Presentation ◽  
T Cell Activation ◽  
Oral Tolerance ◽  
Cell Activation ◽  
Enzyme Linked Immunosorbent Assay ◽  
Protective Agent ◽  
Dependent Manner ◽  
Food Antigens

ABSTRACT The increase in the transcellular passage of intact antigens across the digestive epithelium infected with Helicobacter pylori may interfere with the regulation of mucosal immune responses. The aim of this work was to study the capacity of Helicobacter infection to inhibit the development of oral tolerance or to promote allergic sensitization and the capacity of a gastro-protective agent, rebamipide, to interfere with these processes in mice. Oral tolerance to ovalbumin (OVA) was studied in 48 C3H/He 4-week-old mice divided into four groups: (i) OVA-sensitized mice; (ii) OVA-“tolerized” mice (that is, mice that were rendered immunologically tolerant); (iii) H. felis-infected, OVA-tolerized mice; (iv) and H. felis-infected, OVA-tolerized, rebamipide-treated mice. Oral sensitization to hen egg lysozyme (HEL) was studied in 48 mice divided into four groups: (i) controls; (ii) HEL-sensitized mice; (iii) H. felis-infected, HEL-sensitized mice; and (iv) H. felis-infected, HEL-sensitized, rebamipide-treated mice. Specific anti-OVA or anti-HEL immunoglobulin E (IgE) and IgG1/IgG2a serum titers were measured by enzyme-linked immunosorbent assay. Additionally, the capacity of rebamipide to interfere with antigen presentation and T-cell activation in vitro, as well as absorption of rebamipide across the epithelial monolayer, was tested. H. felis infection led to the inhibition of oral tolerance to OVA, but rebamipide prevented this inhibitive effect of H. felis. H. felis infection did not enhance the sensitization to HEL, but rebamipide inhibited the development of this sensitization. Moreover, rebamipide inhibited in a dose-dependent manner antigen presentation and T-cell activation in vitro and was shown to be able to cross the epithelium at a concentration capable of inducing this inhibitory effect. We conclude that H. felis can inhibit the development of oral tolerance to OVA in mice and that this inhibition is prevented by rebamipide.

scholarly journals Tofacitinib Ameliorates Lupus Through Suppression of T Cell Activation Mediated by TGF-Beta Type I Receptor

2021 ◽  
Vol 12 ◽  
Author(s):  
Qing Yan ◽  
Weiwei Chen ◽  
Hua Song ◽  
Xianming Long ◽  
Zhuoya Zhang ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Lupus Erythematosus ◽  
Cell Activation ◽  
Type I ◽  
Dependent Manner ◽  
Dsdna Antibody

Autoreactive T cells play a crucial role in the pathogenesis of systemic lupus erythematosus (SLE). TGF-β type I receptor (TGFβRI) is pivotal in determining T cell activation. Here, we showed that TGFβRI expression in naïve CD4+ T cells was decreased in SLE patients, especially in those with high disease activity. Moreover, IL-6 was found to downregulate TGFβRI expression through JAK/STAT3 pathway in SLE patients. In vitro, the JAK inhibitor tofacitinib inhibited SLE T cell activating by upregulating TGFβRI expression in a dose-dependent manner. In MRL/lpr mice, tofacitinib treatment ameliorated the clinical indicators and lupus nephritis, as evidenced by reduced plasma anti-dsDNA antibody levels, decreased proteinuria, and lower renal histopathological score. Consistently, tofacitinib enhanced TGFβRI expression and inhibited T cell activation in vivo. TGFβRI inhibitor SB431542 reversed the effects of tofacitinib on T cell activation. Thus, our results have indicated that tofacitinib can suppress T cell activation by upregulating TGFβRI expression, which provides a possible molecular mechanism underlying clinical efficacy of tofacitinib in treating SLE patients.

scholarly journals AHCC Activation and Selection of Human Lymphocytes via Genotypic and Phenotypic Changes to an Adherent Cell Type: A Possible Novel Mechanism of T Cell Activation

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Loretta Olamigoke ◽  
Elvedina Mansoor ◽  
Vivek Mann ◽  
Ivory Ellis ◽  
Elvis Okoro ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Immune Cell ◽  
Human Lymphocytes ◽  
Gene Array ◽  
Adherent Cell ◽  
Immune Cell Activation ◽  
Wide Range

Active Hexose Correlated Compound (AHCC) is a fermented mushroom extract and immune supplement that has been used to treat a wide range of health conditions. It helps in augmentation of the natural immune response and affects immune cell activation and outcomes. The goal of this project was to study and understand the role and mechanisms of AHCC supplementation in the prevention of immunosuppression through T cell activation. The method described here involves “in vitro” culturing of lymphocytes, exposing them to different concentrations of AHCC (0 μg/mL, 50 μg/mL, 100 μg/mL, 250 μg/mL, and 500 μg/mL) at 0 hours. Interestingly, clumping and aggregation of the cells were seen between 24 and 72 hours of incubation. The cells lay down extracellular matrix, which become adherent, and phenotypical changes from small rounded lymphocytes to large macrophage-like, spindle shaped, elongated, fibroblast-like cells even beyond 360 hours were observed. These are probably translated from genotypic changes in the cells since the cells propagate for at least 3 to 6 generations (present observations). RNA isolated was subjected to gene array analysis. We hypothesize that cell adhesion is an activation and survival pathway in lymphocytes and this could be the mechanism of AHCC activation in human lymphocytes.

scholarly journals Spinophilin participates in information transfer at immunological synapses

2008 ◽  
Vol 181 (2) ◽  
pp. 203-211 ◽  
Author(s):  
Ona Bloom ◽  
Julia J. Unternaehrer ◽  
Aimin Jiang ◽  
Jeong-Sook Shin ◽  
Lélia Delamarre ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Activation ◽  
Information Transfer ◽  
Cell Activation ◽  
Immunological Synapse ◽  
Scaffolding Protein ◽  
Dependent Manner ◽  
Immunological Synapses

The adaptive immune response is initiated by the presentation of peptides bound to major histocompatibility complex molecules on dendritic cells (DCs) to antigen-specific T lymphocytes at a junction termed the immunological synapse. Although much attention has been paid to cytoplasmic events on the T cell side of the synapse, little is known concerning events on the DC side. We have sought signal transduction components of the neuronal synapse that were also expressed by DCs. One such protein is spinophilin, a scaffolding protein of neuronal dendritic spines that regulates synaptic transmission. In inactive, immature DCs, spinophilin is located throughout the cytoplasm but redistributes to the plasma membrane upon stimulus-induced maturation. In DCs interacting with T cells, spinophilin is polarized dynamically to contact sites in an antigen-dependent manner. It is also required for optimal T cell activation because DCs derived from mice lacking spinophilin exhibit defects in antigen presentation both in vitro and in vivo. Thus, spinophilin may play analogous roles in information transfer at both neuronal and immunological synapses.

scholarly journals Sex Matters: Physiological Abundance of Immuno-Regulatory CD71+ Erythroid Cells Impair Immunity in Females

2021 ◽  
Vol 12 ◽  
Author(s):  
Siavash Mashhouri ◽  
Petya Koleva ◽  
Mai Huynh ◽  
Isobel Okoye ◽  
Shima Shahbaz ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
The Body ◽  
Dependent Manner ◽  
Erythroid Cells ◽  
Female Mice ◽  
Wide Range ◽  
Arginase Ii

Mature erythrocytes are the major metabolic regulators by transporting oxygen throughout the body. However, their precursors and progenitors defined as CD71+ Erythroid Cells (CECs) exhibit a wide range of immunomodulatory properties. Here, we uncover pronounced sexual dimorphism in CECs. We found female but not male mice, both BALB/c and C57BL/6, and human females were enriched with CECs. CECs, mainly their progenitors defined as CD45+CECs expressed higher levels of reactive oxygen species (ROS), PDL-1, VISTA, Arginase II and Arginase I compared to their CD45− counterparts. Consequently, CECs by the depletion of L-arginine suppress T cell activation and proliferation. Expansion of CECs in anemic mice and also post-menstrual cycle in women can result in L-arginine depletion in different microenvironments in vivo (e.g. spleen) resulting in T cell suppression. As proof of concept, we found that anemic female mice and mice adoptively transferred with CECs from anemic mice became more susceptible to Bordetella pertussis infection. These observations highlight the role of sex and anemia-mediated immune suppression in females. Notably, enriched CD45+CECs may explain their higher immunosuppressive properties in female BALB/c mice. Finally, we observed significantly more splenic central macrophages in female mice, which can explain greater extramedullary erythropoiesis and subsequently abundance of CECs in the periphery. Thus, sex-specific differences frequency in the frequency of CECs might be imprinted by differential erythropoiesis niches and hormone-dependent manner.

Immune Effects of Imatinib in Chronic Myelogenous Leukemia In Vitro.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 2956-2956
Author(s):  
Dagmar Bund ◽  
Raymund Buhmann ◽  
Hans-Jochem Kolb
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Myelogenous Leukemia ◽  
Dependent Manner ◽  
Activation Markers ◽  
Antigen Presenting ◽  
Dose Dependent

Abstract Imatinib mesylate, a potent and selective inhibitor of the BCR-ABL tyrosine kinase, has been shown to induce durable haematological and major cytogenetic responses in a high percentage of CML patients. However in most patients the disease recurs, when imatinib is discontinued. In contrast, allogeneic stem cell transplantation (ASCT) is considered to be curative by the immune effect of donor T cells against CML progenitor cells. In this context, the role of imatinib is controversial; it may improve the results of ASCT by reducing the tumour load, it may also reduce the effect of donor lymphocyte transfusions (DLT) by impairing the function of T cells and the capacity of myeloid cells to present antigen. Patient derived CML-cells were studied for the stimulation of allogeneic HLA-matched and mismatched T-cells in the presence and absence of imatinib. In a 5 day culture the proliferative response of HLA-mismatched T cells was evaluated in presence of different concentrations of imatinib (0, 1, 2, or 5 micro M) and various responder-to-stimulator ratios. Thereby, proliferation was detected via a CFDA based assays and the activation profile (CD25, CD69) of the T-cells was determined by FACS. Cr51-release assays were performed after a 7 day culture of CML cells with HLA-matched T cells to test cytotoxicity of CD8+ T-cells. In addition, we characterized the antigen-presenting profile (CD14, CD33, HLA-DR, CD40, CD80, CD86, CD54, CD58) of the CML cells over a 5 day culture with and without imatinib. The presence of imatinib inhibited the proliferative capacity of allogeneic T-cells in a dose-dependent manner. Also, the expression of T cell activation markers was reduced in the presence of the different imatinib concentrations. Preincubation of CML cells with imatinib for 48 hours strengthened the effect on proliferation and activation of T cells. Moreover, imatinib impaired the cytotoxic function of T-cell (HLA-matched setting; CR51-release assay) also in a dose-dependent manner. Finally, the antigen-presenting profile of the myeloid leukemia cells was down regulated by increasing concentrations of imatinib. In summary, imatinib may interfere with the T cellular immune response and the antigen presenting profile on the CML cells in vitro. These results may have an impact on new strategies of treatment of CML with immunotherapy.

scholarly journals Human Endothelial Cells Enhance Human Immunodeficiency Virus Type 1 Replication in CD4+ T Cells in a Nef-Dependent Manner In Vitro and In Vivo

2005 ◽  
Vol 79 (1) ◽  
pp. 264-276 ◽  
Author(s):  
Jaehyuk Choi ◽  
Jason Walker ◽  
Sergei Boichuk ◽  
Nancy Kirkiles-Smith ◽  
Nicholas Torpey ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Dependent Manner ◽  
Wild Type ◽  
Mhc Ii ◽  
Hiv 1

ABSTRACT Infected CD4+ T cells are the primary sites of human immunodeficiency virus type 1 (HIV-1) replication in vivo. However, signals from professional antigen-presenting cells (APCs), such as dendritic cells and macrophages, greatly enhance HIV-1 replication in T cells. Here, we report that in cocultures, vascular endothelial cells (ECs), which in humans can also serve as APCs, can enhance HIV-1 production of both CCR5- and CXCR4-utilizing strains approximately 50,000-fold. The observed HIV-1 replication enhancement conferred by ECs occurred only in memory CD4+ T cells, required expression of major histocompatibility complex class II (MHC-II) molecules by the ECs, and could not be conferred by fixed ECs, all of which are consistent with a requirement for EC-mediated T-cell activation via T-cell receptor (TCR) signaling. Deletion of nef (Nef−) decreased HIV-1 production by approximately 100-fold in T cells cocultured with ECs but had no effect on virus production in T cells cocultured with professional APCs or fibroblasts induced to express MHC-II. Human ECs do not express B7 costimulators, but Nef− replication in CD4+-T-cell and EC cocultures could not be rescued by anti-CD28 antibody. ECs act in trans to enhance wild-type but not Nef− replication and facilitate enhanced wild-type replication in naïve T cells when added to T-cell or B-lymphoblastoid cell cocultures, suggesting that ECs also provide a TCR-independent signal to infected T cells. Consistent with these in vitro observations, wild-type HIV-1 replicated 30- to 50-fold more than Nef− in human T cells infiltrating allogeneic human skin grafts on human huPBL-SCID/bg mice, an in vivo model of T-cell activation by ECs. Our studies suggest that ECs, which line the entire cardiovascular system and are, per force, in frequent contact with memory CD4+ T cells, provide signals to HIV-1-infected CD4+ T cells to greatly enhance HIV-1 production in a Nef-dependent manner, a mechanism that could contribute to the development of AIDS.

IMMU-35. INDUCTION OF ANTI-TUMOR IMMUNITY BY TUMOR TREATING FIELDS (TTFIELDS) IN GLIOBLASTOMA

2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi100-vi100
Author(s):  
Dongjiang Chen ◽  
Son Le ◽  
Tarun Hutchinson ◽  
Dan Jin ◽  
Mathew Sebastian ◽  
...  
Keyword(s):  
T Cell ◽  
Nuclear Envelope ◽  
T Cell Activation ◽  
Murine Model ◽  
Cell Activation ◽  
Clonal Expansion ◽  
Intermediate Frequency ◽  
Dependent Manner ◽  
Newly Diagnosed

Abstract INTRODUCTION The novel approved GBM treatment TTFields employs alternating, intermediate-frequency (200kHz) electric fields to disrupt mitotic macromolecules leading to chromosome mis-segregation and apoptosis. Emerging evidence indicates that TTFields may also induce inflammation; however, the mechanism and whether this can be harnessed as cancer immunotherapy remain unclear. METHODS Multiple GBM cell lines were treated with TTFields using Inovitro, an in vitro TTFields system and integrity of the nuclear envelope and content and activation of key DNA sensor inflammatory pathways analyzed by immunostaining, expression profiling, and protein assays. In a syngeneic orthotopic murine model, TTFields-treated GBM cells were used to provide an in-situ vaccination platform. For validation, we performed bulk and single-cell RNAseq of PBMCs from 12 newly diagnosed GBM patients treated with TTFields. RESULTS TTFields induce focal disruption of the nuclear envelope, leading to cytosolic release of large micronuclei clusters that recruit and intensely activate the 2 major DNA sensors – cGAS and AIM2, and their cognate inflammasomes, thereby releasing pro-inflammatory cytokines and type-1 interferons (T1IFNs) that promote development and maturation of DCs and cytotoxic T cells. In murine model, TTFields-treated GBM cells induce anti-tumor memory immunity both intratumorally and systemically, producing a cure rate of 40% and partial immunity in an additional 25% in a STING- and AIM2-dependent manner. In patients with newly diagnosed GBM patients, we sequenced a total of 193,760 PBMCs and detected robust post-TTFields activation of adaptive immunity via the T1IFN trajectory anchored by plasmacytoid DCs, which was strongly correlated with the TCRαβ clonal expansion index observed in 11 of 12 patients (Spearman coefficient r=-0.8, P=0.014). Importantly, we also defined a T cell-based gene signature predictive of TTFields effects on T cell activation and TCRαβ clonal expansion. CONCLUSION Collectively, these studies define a novel strategy using TTFields to improve immunotherapy in GBM and potentially other solid tumors.

scholarly journals Combinatorial Control of Signal-Induced Exon Repression by hnRNP L and PSF

2007 ◽  
Vol 27 (19) ◽  
pp. 6972-6984 ◽  
Author(s):  
Alexis A. Melton ◽  
Jason Jackson ◽  
Jiarong Wang ◽  
Kristen W. Lynch
Keyword(s):  
T Cells ◽  
Alternative Splicing ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Cell Function ◽  
Exon Skipping ◽  
Dependent Manner

ABSTRACT Cells can regulate their protein repertoire in response to extracellular stimuli via alternative splicing; however, the mechanisms controlling this process are poorly understood. The CD45 gene undergoes alternative splicing in response to T-cell activation to regulate T-cell function. The ESS1 splicing silencer in CD45 exon 4 confers basal exon skipping in resting T cells through the activity of hnRNP L and confers activation-induced exon skipping in T cells via previously unknown mechanisms. Here we have developed an in vitro splicing assay that recapitulates the signal-induced alternative splicing of CD45 and demonstrate that cellular stimulation leads to two changes to the ESS1-bound splicing regulatory complex. Activation-induced posttranslational modification of hnRNP L correlates with a modest increase in the protein's repressive activity. More importantly, the splicing factor PSF is recruited to the ESS1 complex in an activation-dependent manner and accounts for the majority of the signal-regulated ESS1 activity. The associations of hnRNP L and PSF with the ESS1 complex are largely independent of each other, but together these proteins account for the total signal-regulated change in CD45 splicing observed in vitro and in vivo. Such a combinatorial effect on splicing allows for precise regulation of signal-induced alternative splicing.

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