scholarly journals Immunomodulatory Effects Associated with Cladribine Treatment

Cells ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 3488
Author(s):  
Nicolás Fissolo ◽  
Laura Calvo-Barreiro ◽  
Herena Eixarch ◽  
Ursula Boschert ◽  
Carmen Espejo ◽  
...  
Keyword(s):  
Mechanism Of Action ◽  
Cell Activation ◽  
Mononuclear Cells ◽  
Immune Cell ◽  
Active Form ◽  
In Vitro Study ◽  
Peripheral Blood Mononuclear ◽  
Prodrug Activation ◽  
The Impact

Cladribine is a synthetic deoxyadenosine analogue with demonstrated efficacy in patients with relapsing-remitting multiple sclerosis (MS). The main mechanism of action described for cladribine is the induction of a cytotoxic effect on lymphocytes, leading to a long-term depletion of peripheral T and B cells. Besides lymphocyte toxicity, the mode of action may include immunomodulatory mechanisms affecting other cells of the immune system. In order to induce its beneficial effects, cladribine is phosphorylated inside the cell by deoxycytidine kinase (DCK) to its active form. However, the mechanism of action of cladribine may also include immunomodulatory pathways independent of DCK activation. This in vitro study was designed to explore the impact of cladribine on peripheral blood mononuclear cells (PBMC) subsets, and to assess whether the immunomodulatory mechanisms induced by cladribine depend on the activation of the molecule. To this end, we obtained PBMCs from healthy donors and MS patients and performed proliferation, apoptosis and activation assays with clinically relevant concentrations of cladribine in DCK-dependent and -independent conditions. We also evaluated the effect of cladribine on myeloid lineage-derived cells, monocytes and dendritic cells (DCs). Cladribine decreased proliferation and increased apoptosis of lymphocyte subsets after prodrug activation via DCK. In contrast, cladribine induced a decrease in immune cell activation through both DCK-dependent and -independent pathways (not requiring prodrug activation). Regarding monocytes and DCs, cladribine induced cytotoxicity and impaired the activation of classical monocytes, but had no effect on DC maturation. Taken together, these data indicate that cladribine, in addition to its cytotoxic function, can mediate immunomodulation in different immune cell populations, by regulating their proliferation, maturation and activation.

scholarly journals A167 UNDERSTANDING THE IMPACT OF DOWNSTREAM OF KINASE 4 (DOK4) DAMAGING GENETIC VARIANTS IN THE PATHOGENESIS OF PEDIATRIC INFLAMMATORY BOWEL DISEASE (IBD).

2021 ◽  
Vol 4 (Supplement_1) ◽  
pp. 177-178
Author(s):  
V Batura ◽  
A Ricciuto ◽  
N Warner ◽  
C Guo ◽  
D Kotlarz ◽  
...  
Keyword(s):  
Cell Signaling ◽  
Cell Activation ◽  
Mononuclear Cells ◽  
Immune Cell ◽  
Genetic Variations ◽  
Inflammatory Disorder ◽  
Loss Of Function ◽  
Peripheral Blood Mononuclear ◽  
Genetic Sequencing ◽  
The Impact

Abstract Background IBD is a chronic inflammatory disorder of the gastrointestinal (GI) tract whose precise pathological mechanisms remain elusive. It is thought that in pediatric IBD, pathogenic exposure does not appear sufficient to cause disease, thus genetic variations are critical to disease pathogenesis. The Muise Lab uses genetic sequencing of patients with IBD from all over the world to identify crucial genetic variations that are critical to IBD development. We report two patients with IBD from unrelated families with mutations in DOK4. Both patients had profound extra-intestinal disease complicating their IBD. Downstream of kinase (DOK) proteins are a family of adaptor molecules that are important in regulating cell signaling, especially in immune cells. They are known to suppress MAPK and PI3K/AKT pathways, whose dysregulation result in cancer. DOK4 has not been extensively studied, but research suggests that this gene produces two isoforms. It is known to have negative regulatory effects on immune cell activation but is also expressed across various other tissues, where its function is yet to be determined. Aims We hypothesize that these variations in DOK4 lead to immune cell dysregulation, which manifests in both gastrointestinal and systemic chronic inflammatory disease. Through this study, we aim to elucidate the mechanism of novel genetic defects in DOK4. Methods It will be critical to understand how variants within both patients are contributing to the onset of IBD through in vitro studies. Therefore, we will characterize and quantify how changes in expression of DOK4 alters essential cell signaling pathways. We have established immortalized cell lines from patients bearing these mutations to specifically characterize potential immune defects. We will also be using knock out cell models to understand the effect of loss of function of DOK4 in different cell types. Results Preliminary data shows variation in expression of the protein within patient peripheral blood mononuclear cells (PBMCs) compared to a healthy donor. Overexpression in HEK293T cells shows changes in MAPK and NFkB signaling. Conclusions With this study, we hope to identify new therapeutic targets for patients with DOK4 mutations. Funding Agencies CIHRThe Leona M. and Harry B. Helmsley Charitable Trust

scholarly journals Endogenous retrovirus-encoded Syncytin-2 contributes to exosome-mediated immunosuppression of T cells†

2019 ◽  
Author(s):  
Adjimon G Lokossou ◽  
Caroline Toudic ◽  
Phuong Trang Nguyen ◽  
Xavier Elisseeff ◽  
Amandine Vargas ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell Activation ◽  
Map Kinases ◽  
Cell Activation ◽  
Mononuclear Cells ◽  
Immune Cell ◽  
Endogenous Retrovirus ◽  
Jurkat Cells ◽  
Peripheral Blood Mononuclear ◽  
Interfering Rna

Abstract Modulation of the activation status of immune cell populations during pregnancy depends on placental villous cytotrophoblast (VCT) cells and the syncytiotrophoblast (STB). Failure in the establishment of this immunoregulatory function leads to pregnancy complications. Our laboratory has been studying Syncytin-2 (Syn-2), an endogenous retroviral protein expressed in placenta and on the surface of placental exosomes. This protein plays an important role not only in STB formation through its fusogenic properties, but also through its immunosuppressive domain (ISD). Considering that Syn-2 expression is importantly reduced in preeclamptic placentas, we were interested in addressing its possible immunoregulatory effects on T cells. Activated Jurkat T cells and peripheral blood mononuclear cells (PBMCs) were treated with monomeric or dimerized version of a control or a Syn-2 ISD peptide. Change in phosphorylation levels of ERK1/2 MAP kinases was selectively noted in Jurkat cells treated with the dimerized ISD peptide. Upon incubation with the dimerized Syn-2 ISD peptide, significant reduction in Th1 cytokine production was further demonstrated by ELISA and Human Th1/Th2 Panel Multi-Analyte Flow Assay. To determine if exosome-associated Syn-2 could also be immunosuppressive placental exosomes were incubated with activated Jurkat and PBMCs. Quantification of Th1 cytokines in the supernatants revealed severe reduction in T cell activation. Interestingly, exosomes from Syn-2-silenced VCT incubated with PBMCs were less suppressive when compared with exosome derived from VCT transfected with control small interfering RNA (siRNA). Our results suggest that Syn-2 is an important immune regulator both locally and systemically, via its association with placental exosomes.

scholarly journals Anticancer immunity induced by a synthetic tumor-targeted CD137 agonist

2021 ◽  
Vol 9 (1) ◽  
pp. e001762
Author(s):  
Punit Upadhyaya ◽  
Johanna Lahdenranta ◽  
Kristen Hurov ◽  
Sailaja Battula ◽  
Rachel Dods ◽  
...  
Keyword(s):  
Mononuclear Cells ◽  
Tumor Antigens ◽  
Immune Cell ◽  
Checkpoint Inhibitors ◽  
Human Peripheral Blood ◽  
Interleukin 2 ◽  
Cancer Therapeutics ◽  
Peripheral Blood Mononuclear ◽  
Tnf Superfamily

BackgroundIn contrast to immune checkpoint inhibitors, the use of antibodies as agonists of immune costimulatory receptors as cancer therapeutics has largely failed. We sought to address this problem using a new class of modular synthetic drugs, termed tumor-targeted immune cell agonists (TICAs), based on constrained bicyclic peptides (Bicycles).MethodsPhage libraries displaying Bicycles were panned for binders against tumor necrosis factor (TNF) superfamily receptors CD137 and OX40, and tumor antigens EphA2, Nectin-4 and programmed death ligand 1. The CD137 and OX40 Bicycles were chemically conjugated to tumor antigen Bicycles with different linkers and stoichiometric ratios of binders to obtain a library of low molecular weight TICAs (MW <8 kDa). The TICAs were evaluated in a suite of in vitro and in vivo assays to characterize their pharmacology and mechanism of action.ResultsLinking Bicycles against costimulatory receptors (e.g., CD137) to Bicycles against tumor antigens (e.g., EphA2) created potent agonists that activated the receptors selectively in the presence of tumor cells expressing these antigens. An EphA2/CD137 TICA (BCY12491) efficiently costimulated human peripheral blood mononuclear cells in vitro in the presence of EphA2 expressing tumor cell lines as measured by the increased secretion of interferon γ and interleukin-2. Treatment of C57/Bl6 mice transgenic for the human CD137 extracellular domain (huCD137) bearing EphA2-expressing MC38 tumors with BCY12491 resulted in the infiltration of CD8+ T cells, elimination of tumors and generation of immunological memory. BCY12491 was cleared quickly from the circulation (plasma t1/2 in mice of 1–2 hr), yet intermittent dosing proved effective.ConclusionTumor target-dependent CD137 agonism using a novel chemical approach (TICAs) afforded elimination of tumors with only intermittent dosing suggesting potential for a wide therapeutic index in humans. This work unlocks a new path to effective cancer immunotherapy via agonism of TNF superfamily receptors.

scholarly journals The effect of a short-term low-carbohydrate, high-fat diet with or without postmeal walks on glycemic control and inflammation in type 2 diabetes: a randomized trial

2018 ◽  
Vol 315 (6) ◽  
pp. R1210-R1219 ◽  
Author(s):  
Étienne Myette-Côté ◽  
Cody Durrer ◽  
Helena Neudorf ◽  
Tyler D. Bammert ◽  
José Diego Botezelli ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Glycemic Control ◽  
Cell Activation ◽  
Mononuclear Cells ◽  
Immune Cell ◽  
High Fat ◽  
Peripheral Blood Mononuclear ◽  
Time Interaction ◽  
Low Carbohydrate

Lowering carbohydrate consumption effectively lowers glucose, but impacts on inflammation are unclear. The objectives of this study were to: 1) determine whether reducing hyperglycemia by following a low-carbohydrate, high-fat (LC) diet could lower markers of innate immune cell activation in type 2 diabetes (T2D) and 2) examine if the combination of an LC diet with strategically timed postmeal walking was superior to an LC diet alone. Participants with T2D ( n = 11) completed a randomized crossover study involving three 4-day diet interventions: 1) low-fat low-glycemic index (GL), 2) and 3) LC with 15-min postmeal walks (LC+Ex). Four-day mean glucose was significantly lower in the LC+Ex group as compared with LC (−5%, P < 0.05), whereas both LC+Ex (−16%, P < 0.001) and LC (−12%, P < 0.001) conditions were lower than GL. A significant main effect of time was observed for peripheral blood mononuclear cells phosphorylated c-Jun N-terminal kinase ( P < 0.001), with decreases in all three conditions (GL: −32%, LC: −45%, and LC+Ex: −44%). A significant condition by time interaction was observed for monocyte microparticles ( P = 0.040) with a significant decrease in GL (−76%, P = 0.035) and a tendency for a reduction in LC (−70%, P = 0.064), whereas there was no significant change in LC+Ex (0.5%, P = 0.990). Both LC (−27%, P = 0.001) and LC+Ex (−35%, P = 0.005) also led to significant reductions in circulating proinsulin. An LC diet improved 4-day glycemic control and fasting proinsulin levels when compared with GL, with added glucose-lowering benefits when LC was combined with postmeal walking.

scholarly journals Evaluation of apoptotic potential of glyphosate metabolites and impurities in human peripheral blood mononuclear cells (in vitro study)

2020 ◽  
Vol 135 ◽  
pp. 110888 ◽  
Author(s):  
Marta Kwiatkowska ◽  
Jaromir Michałowicz ◽  
Paweł Jarosiewicz ◽  
Daria Pingot ◽  
Paulina Sicińska ◽  
...  
Keyword(s):  
Peripheral Blood Mononuclear Cells ◽  
Peripheral Blood ◽  
Mononuclear Cells ◽  
Human Peripheral Blood ◽  
In Vitro Study ◽  
Vitro Study ◽  
Peripheral Blood Mononuclear ◽  
Blood Mononuclear Cells

scholarly journals Administration of cardiac mesenchymal cells modulates innate immunity in the acute phase of myocardial infarction in mice

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Yi Kang ◽  
Marjan Nasr ◽  
Yiru Guo ◽  
Shizuka Uchida ◽  
Tyler Weirick ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Innate Immunity ◽  
Mechanism Of Action ◽  
Cell Activation ◽  
Cell Function ◽  
Immune Cell ◽  
Mesenchymal Cell ◽  
Cell Types

Abstract Although cardiac mesenchymal cell (CMC) therapy mitigates post-infarct cardiac dysfunction, the underlying mechanisms remain unidentified. It is acknowledged that donor cells are neither appreciably retained nor meaningfully contribute to tissue regeneration—suggesting a paracrine-mediated mechanism of action. As the immune system is inextricably linked to wound healing/remodeling in the ischemically injured heart, the reparative actions of CMCs may be attributed to their immunoregulatory properties. The current study evaluated the consequences of CMC administration on post myocardial infarction (MI) immune responses in vivo and paracrine-mediated immune cell function in vitro. CMC administration preferentially elicited the recruitment of cell types associated with innate immunity (e.g., monocytes/macrophages and neutrophils). CMC paracrine signaling assays revealed enhancement in innate immune cell chemoattraction, survival, and phagocytosis, and diminished pro-inflammatory immune cell activation; data that identifies and catalogues fundamental immunomodulatory properties of CMCs, which have broad implications regarding the mechanism of action of CMCs in cardiac repair.

scholarly journals IMMU-46. EXAMINATION OF THE EFFECTS OF DEXAMETHASONE ON THE EFFICACY OF IMMUNOTHERAPY IN GLIOMA USING GENE-MEDIATED CYTOTOXIC IMMUNOTHERAPY

2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi129-vi129
Author(s):  
Marilin Koch ◽  
Mykola Zdioruk ◽  
M Oskar Nowicki ◽  
Estuardo Aguilar ◽  
Laura Aguilar ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Cell Function ◽  
Immune Cell ◽  
Symptomatic Treatment ◽  
Tumor Cell Death ◽  
The Impact

Abstract RATIONALE Dexamethasone is frequently used in symptomatic treatment of glioma patients, although it is known to cause immune suppression. Checkpoint inhibitor immunotherapies have not yet been successful in glioma treatments. Gene-mediated cytotoxic immunotherapy (GMCI) is an immunotherapeutic approach that uses aglatimagene besadenovec with an anti-herpetic prodrug to induce immunogenic tumor cell death and immune cell attraction to the tumor site with potent CD8 T cell activation. GMCI is currently in clinical trials for solid tumors including glioblastoma, where it showed encouraging survival results in a Phase 2 study that did not limit the use of dexamethasone. However, the effects of dexamethasone on its efficacy have not been explored. METHODS We investigated the effects of dexamethasone on GMCI in vitro using cytotoxicity and T-cell-killing assays in glioblastoma cell lines. The impact of dexamethasone in vivo was assessed in an orthotopic syngeneic murine glioblastoma model. RESULTS Cyotoxicity assays showed that Dexamethasone has a slight impact on GMCI in vitro. In contrast, we observed a highly significant effect in T-cell-functional assays in which killing was greatly impaired. Immune cell response assays revealed a reduced T-cell proliferation after co-culture with supernatant from dexamethasone or combination treated glioblastoma cells in contrast to GMCI alone. In a murine model, the combination of GMCI and dexamethasone resulted in a significant reduction in median symptom-free survival (29d) in comparison to GMCI alone (39.5d) (P = 0.0184). CONCLUSION Our data suggest that high doses of dexamethasone may negatively impact the efficacy of immunotherapy for glioma, which may be a consequence of impaired T cell function. These results support the idea that there is a need in identifying possible alternatives to dexamethasone to maximize the effectiveness of immunostimulatory therapies such as GMCI.

scholarly journals Characterization of the T-Cell Receptor Vβ Repertoire in the Human Immune Response against Leishmania Parasites

2006 ◽  
Vol 74 (8) ◽  
pp. 4757-4765 ◽  
Author(s):  
Jorge Clarêncio ◽  
Camila I. de Oliveira ◽  
Glória Bomfim ◽  
Margarida M. Pompeu ◽  
Maria Jania Teixeira ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Mononuclear Cells ◽  
Cell Receptor ◽  
Peripheral Blood Mononuclear ◽  
Cell Clones ◽  
Human Immune Response ◽  
Lymph Node Cells

ABSTRACT In order to explore a possible presence of hyperreactive T-cell clones in human cutaneous leishmaniasis (CL), we have investigated, by flow cytometry, the expression of Vβ chains of T-cell receptors (TCRs) in the following types of cells: (i) peripheral blood mononuclear cells (PBMCs) from CL patients, which were then compared to those from normal volunteers; (ii) unstimulated and soluble Leishmania antigen-stimulated draining lymph node cells from CL patients; (iii) PBMCs from volunteers before versus after Leishmania immunization; and (iv) PBMCs from healthy volunteers that were primed in vitro with live Leishmania parasites. Our results show a modulation in the TCR Vβ repertoire during CL and after antigen stimulation of patients' cells. Vaccination, however, leads to a broad expansion of different Vβ TCRs. We also observed an association between TCR Vβ12 expression, T-cell activation, and gamma interferon production upon in vitro priming with Leishmania. Collectively, these results both indicate that infection with live parasites or exposure to parasite antigen can modulate the TCR Vβ repertoire and suggest that TCR Vβ12 may be implicated in the response to Leishmania.

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