Immunopotent Polysaccharides of Different Sources Selectively Activate Human Dendritic Cells.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 3873-3873
Author(s):  
Godfrey ChiFung Chan ◽  
W.K. Chan ◽  
H.K. Law ◽  
Z.B. Lin ◽  
Y.L. Lau
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
Mononuclear Cells ◽  
Human Peripheral Blood ◽  
T Helper ◽  
T Helper 1 ◽  
Xtt Assay ◽  
Peripheral Blood Mononuclear ◽  
Human Dendritic Cells

Abstract Background: Purified polysaccharides extracted from plants and fungi have been shown to induce immune responses in-vivo and vitro over the past decade. Currently, most of these polysaccharides are found to be glucan but with different branch structure and sizes. Their relative potency and effect on human immune cells remains unknown. This study aims to compare their relative effect on human dendritic cell, the most potent antigen presenting cell. Materials & Methods: We selected 2 prototypes of purified polysaccharides extracted from: 1) Ganoderma lucidum (GL, Lingzhi, Reishi) mycelium, a widely used herb with long and branching β (1® 3), (1® 6) glucan structure (provided by Prof. Lin ZB, Beijing) and 2) Barley with shorter and different branching β (1® 3), (1® 4) structure (provided by Prof. Cheung VNK, NY). Their characteristics and chemical properties had been reported previously. Human peripheral blood mononuclear cells (PBMCs) proliferation was studied by XTT assay. Human dendritic cells (DCs) were derived from monocytes and maturation of DCs were determined by: a) immunophenotypic shift using flow cytometer; 2) dextran endocytosis assay and 3) mixed lymphocytes reaction. Cytokine secretions were determined by ELISA test. Comparisons between means were by nonparametric Student’s t test (2-tailed). Results: We found that purified polysaccharides from GL but not barley could induce PBMCs proliferation and maturation of DCs. GL polysaccharides could enhance phenotypic and functional maturation of DCs with significant IL-12 and IL-10 production. DCs were relatively inert to Barley glucans stimulation. However, both polysaccharides did not polarize T cells into the direction of T helper 1, T helper 2 or regulatory T cells. Conclusions: Our study shown that purified polysaccharides extracted from plants and fungi have different effect on human DCs and their potency and effects are probably affected by their respective sources and structures.

Evaluation of the potential anti-allergic effects of heat-inactivated Lactobacillus paracasei V0151 in vitro, ex vivo, and in vivo

2015 ◽  
Vol 6 (5) ◽  
pp. 697-705 ◽  
Author(s):  
Y.W. Liu ◽  
T.Y. Fu ◽  
W.S. Peng ◽  
Y.H. Chen ◽  
Y.M. Cao ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Mononuclear Cells ◽  
Ex Vivo ◽  
Human Peripheral Blood ◽  
Lactobacillus Paracasei ◽  
Raw 264.7 Cells ◽  
Inflammatory Factors ◽  
T Helper ◽  
T Helper 1 ◽  
Peripheral Blood Mononuclear

The efficacy of Lactobacillus paracasei V0151 (V0151), isolated from the faeces of a child, to modulate immune responses was investigated. In RAW 264.7 cells expressing an inducible nitric oxide synthase (iNOS)-directed luciferase gene, heat-inactivated V0151 stimulated iNOS expression followed by nitric oxide production. V0151 significantly elevated interferon gamma, interleukin (IL)-10, tumour necrosis factor alpha, and IL-1β production in human peripheral blood mononuclear cells. In splenocytes isolated from ovalbumin (OVA)-sensitised BALB/c mice treated with OVA and V0151 at different bacterium-to-cell ratios (1:1, 10:1, and 20:1) for 96 h, IL-2, IL-4, IL-5, and IL-13 production was dose-dependently downregulated, whereas IL-12 was dose-dependently upregulated. Collectively, our findings indicate that V0151 might regulate pro-inflammatory factors in macrophages and splenocytes. Furthermore, the T helper 1/T helper 2 (Th1/Th2) balance was also skewed toward Th1 dominance through the elevation of Th1 cytokine production.

scholarly journals Adjuvant Activity of Synthetic Lipid A of Alcaligenes, a Gut-Associated Lymphoid Tissue-Resident Commensal Bacterium, to Augment Antigen-Specific IgG and Th17 Responses in Systemic Vaccine

Vaccines ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 395 ◽  
Author(s):  
Yunru Wang ◽  
Koji Hosomi ◽  
Atsushi Shimoyama ◽  
Ken Yoshii ◽  
Haruki Yamaura ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Mhc Class Ii ◽  
Lipid A ◽  
Mononuclear Cells ◽  
Human Peripheral Blood ◽  
T Helper ◽  
T Helper 17 ◽  
Adjuvant Activity ◽  
Peripheral Blood Mononuclear ◽  
Specific Igg

Alcaligenes spp. are identified as commensal bacteria and have been found to inhabit Peyer’s patches in the gut. We previously reported that Alcaligenes-derived lipopolysaccharides (LPS) exerted adjuvant activity in systemic vaccination, without excessive inflammation. Lipid A is one of the components responsible for the biological effect of LPS and has previously been applied as an adjuvant. Here, we examined the adjuvant activity and safety of chemically synthesized Alcaligenes lipid A. We found that levels of OVA-specific serum IgG antibodies increased in mice that were subcutaneously immunized with ovalbumin (OVA) plus Alcaligenes lipid A relative to those that were immunized with OVA alone. In addition, Alcaligenes lipid A promoted antigen-specific T helper 17 (Th17) responses in the spleen; upregulated the expression of MHC class II, CD40, CD80, and CD86 on bone marrow-derived dendritic cells (BMDCs); enhanced the production of Th17-inducing cytokines IL-6 and IL-23 from BMDCs. Stimulation with Alcaligenes lipid A also induced the production of IL-6 and IL-1β in human peripheral blood mononuclear cells. Moreover, Alcaligenes lipid A caused minor side effects, such as lymphopenia and thrombocytopenia. These findings suggest that Alcaligenes lipid A is a safe and effective Th17-type adjuvant by directly stimulating dendritic cells in systemic vaccination.

The Existence Of T Helper (Tμ) And T Suppressor (Tγ) Cells For The Generation Of Monocyte Thromboplastin Activity By Lipopolysaccharides

1981 ◽  
Author(s):  
G A Levy ◽  
B S Schwartz ◽  
T S Edqinqton
Keyword(s):  
T Cells ◽  
T Lymphocyte ◽  
Mononuclear Cells ◽  
Cell Function ◽  
Human Peripheral Blood ◽  
Pokeweed Mitogen ◽  
T Helper ◽  
Peripheral Blood Mononuclear ◽  
Cellular Source ◽  
Two Populations

Human peripheral blood mononuclear cells (PBM) in response to LPS stimulation generate increased quantities of thromboplastin activity. Monocytes are the cellular source of this activity and direct lymphocyte collaboration is required for its expression. PBM were separated by adherence into monocyte and lymphocyte fractions. Lymphocytes were further fractionated into T and non-T cells by rosetting with neuraminidase treated SRBC. 1 × 105 monocytes had a basal activity of 250 mU which increased to a maximum 2850 mU when monocytes were stimulated by 10 ug LPS for 6 hrs at a T cell: monocyte ratio of 4:1. No increase in thromboplastin activity was observed when monocytes were stimulated by LPS either alone or in the presence of non-T cells. Moretta et al. have described a system in which T cells are segregated into helper and suppressor subsets according to their ability to mediate immunoglobulin synthesis in response to pokeweed mitogen (PWM) stimulation. Using this system, T cells were further subfractionated into helper (Tμ), suppressor (Tγ ) and T null cells by cytoadherence to IgM or IgG coated ox RBC. 1 × 105 monocytes when incubated with increasing numbers of Tμ cells generated a maximal 4150 mU thromboplastin activity as the ratio of Tμ: monocytes approached 4:1. No increase in monocyte thromboplastin activity was observed above basal levels of 160 mU when monocytes were stimulated by LPS in the presence of either Tγ or T null cells. Tγ cells were observed to suppress Tμ helper cell function with a decrease in monocyte thromboplastin activity from 4150 mU to 1100 mU as the Tγ: Tμ ratio increased from 0:1 to 4:1. Thus, at least two populations within the T lymphocyte series the T μ (helper) and Tγ (suppressor) fractions modulate the expression of thromboplastin activity by monocytes.

High levels of thyroid hormone impair regulatory T cells function via reduced PD-1 expression

2021 ◽  
Author(s):  
Yi Zhong ◽  
Ting-Ting Lu ◽  
Xiao-Mei Liu ◽  
Bing-Li Liu ◽  
Yun Hu ◽  
...  
Keyword(s):  
T Cells ◽  
Thyroid Hormone ◽  
Regulatory T Cells ◽  
Mononuclear Cells ◽  
Human Peripheral Blood ◽  
Dependent Manner ◽  
Peripheral Blood Mononuclear

Abstract Context Regulatory T cells (Tregs) dysfunction plays an important role in the development and progression of Graves’ disease (GD). Programmed cell death 1 (PD-1) prompts FoxP3 in Tregs expression and enhances the suppressive activity of Tregs. Whether abnormal expression of PD-1 contributes to the breakdown of Tregs and the role of thyroid hormone in the PD-1 expression of Tregs in GD remain substantially undefined. Objective To evaluate the role of PD-1 in Tregs function and triiodothyronine (T3) in PD-1 expression in patients with GD and mice treated with T3. Methods We recruited 30 patients with GD and 30 healthy donors. PD-1 expression in Tregs and Tregs function were determined. To evaluate the effects of thyroid hormone on PD-1 expression in Tregs, we used T3 for the treatment of human peripheral blood mononuclear cells (PBMCs). We then treated mice with T3 to confirm the effect of thyroid hormone on PD-1 expression in Tregs and Tregs function in vivo. Results PD-1 expression in Tregs and the suppressive function of Tregs significantly decreased in patients with GD. T3 reduced PD-1 expression in human Tregs in a concentration- and time-dependent manner in vitro. High levels of circulating T3 reduced PD-1 expression in Tregs, impaired Tregs function, and disrupted T-helper cell (Th1 and Th2) balance in mice treated with T3. Conclusions Tregs dysfunction in GD patients might be due to down-regulation of PD-1 expression in Tregs induced by high levels of serum T3.

scholarly journals TLR7 and RIG-I dual-adjuvant loaded nanoparticles drive broadened and synergistic responses in dendritic cells in vitro and generate unique cellular immune responses in influenza vaccination

2020 ◽  
Author(s):  
Randall Toy ◽  
M. Cole Keenum ◽  
Pallab Pradhan ◽  
Katelynn Phang ◽  
Patrick Chen ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
Immune Responses ◽  
Cellular Immunity ◽  
Mononuclear Cells ◽  
Human Peripheral Blood ◽  
Mouse Bone Marrow ◽  
Peripheral Blood Mononuclear ◽  
Flu Vaccination

ABSTRACTAlthough the existing flu vaccines elicit strong antigen-specific antibody responses, they fail to provide effective, long term protection – partly due to the absence of robust cellular memory immunity. We hypothesized that co-administration of combination adjuvants, mirroring the flu-virus related innate signaling pathways, could elicit strong cellular immunity. Here, we show that the small molecule adjuvant R848 and the RNA adjuvant PUUC, targeting endosomal TLR7s and cytoplasmic RLRs respectively, when delivered together in polymer nanoparticles (NP), elicits a broadened immune responses in mouse bone marrow-derived dendritic cells (mBMDCs) and a synergistic response in both mouse and human plasmacytoid dendritic cells (pDCs). In mBMDCs, NP-R848-PUUC induced both NF-κB and interferon signaling. Interferon responses to co-delivered R848 and PUUC were additive in human peripheral blood mononuclear cells (PBMCs) and synergistic in human FLT3-differentiated mBMDCs and CAL-1 pDCs. Vaccination with NPs loaded with H1N1 Flu antigen, R848, and PUUC increased percentage of CD8+ T-cells in the lungs, percentage of antigen-specific CD4+T-cells in the spleen, and enhanced overall cytokine-secreting T cell percentages upon antigen restimulation. Also in the spleen, T lymphopenia, especially after in vitro restimulation, was observed. Our results demonstrate that simultaneous engagement of TLR7 and RIG-I pathways using particulate carriers is a potential approach to improve cellular immunity in flu vaccination.GRAPHICAL ABSTRACT

Decitabine Can Increase the Induction of Regulatory γδ T Cells with Enhanced Immunosuppression on Graft-Versus-Host Disease From Adult Human Peripheral Blood Mononuclear Cells

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 1901-1901 ◽  
Author(s):  
Yongxian Hu ◽  
Yanjun Gu ◽  
Lixia Sheng ◽  
Huarui Fu ◽  
Kangni Wu ◽  
...  
Keyword(s):  
T Cells ◽  
Survival Time ◽  
Mononuclear Cells ◽  
Human Peripheral Blood ◽  
Γδ T Cells ◽  
Foxp3 Expression ◽  
Peripheral Blood Mononuclear ◽  
Tgf Β1

Abstract Abstract 1901 Regulatory γδ T cells (γδ Tregs) is a novel subset of cells with immunosuppressive function while methods for γδ Treg induction is rarely introduced and its role in graft-versus-host disease (GVHD) prevention remains unkown. Decitabine, a kind of hypomethylating agents, can act synergistically with TGF-β1 to convert a variety of αβ T cells to regulatory αβ T cells with suppressive function but its role in induction and function of γδ Tregs has not been reported. We show here the role of decitabine for the induction of γδ Tregs. Moreover, we provide functional analysis and underlying mechanisms of decitabine-induced γδ Tregs relative to γδ Tregs without decitabine induction as well as in vivo evidences of their preventions on GVHD. Human peripheral blood mononuclear cells (PBMCs) were cultured with IL-2, IL-15, TGF-β1 and zoledronic acid (ZOL). On day 2, 0.5μmol/ml decitabine was added to aliquots of PBMCs. On days 4, 7, and 10, half of the supernatant volume was replaced with media containing cytokines. On day 11, frequencies of γδ Tregs were detected by flow cytometry (FACS). We found the frequency of γδ Tregs was 36.2% in TGF-β1/IL-15/ZOL stimulated group (referred to as common γδ Tregs below) and 59.9% in IL-2/TGF-β1/IL-15/ZOL/decitabine stimulated group (referred to as decitabine-induced γδ Tregs) (p<0.05). In order to compare immunosuppressive function of the two populations, γδ T cells containing γδ Tregs were isolated by magnetic cell sorting system (MACS) and tested for their ability to suppress proliferation of alloreactive PBMCs using CFSE-based assay. After 5 days of in vitro culture, CFSE-labeled PBMCs proliferation was significantly reduced in the presence of enriched γδ Tregs even at 8:1(PBMCs: γδ Tregs) ratio. The inhibition rate was significantly different (decitabine-induced γδ Tregs VS common γδ Tregs at ratio 1:1 is 81.3% VS 68.2%, p<0.05). To clarify the underlying mechanisms we performed ELISA to measure levels of inhibitory cytokines IL-10, IL-4 and TGF-β1 in supernatant of CFSE-based assay. We noted an elevated IL-10 secretion in the decitabine-induced γδ Tregs group compared with common γδ Tregs group (92.7±11pg/ml VS 10.3±2pg/ml at ratio 1:1, p<0.01). We confirmed the result by intracellular IL-10 detection using FACS. Previous reports showed high levels of inducible T-cell costimulator (ICOS) were correlated with IL-10 synthesis. So γδ Tregs were monitored for ICOS expression by FACS. The result revealed that ICOS expression was up-regulated in decitabine-induced γδ Tregs in contrast to common γδ Tregs (MFI: 268 VS 54). Stability of Foxp3 is a critical factor in the immunosuppressive ability of Tregs. Thus we evaluated the frequency of γδ Tregs after 5 days in CFSE-based assay. We observed loss of Foxp3 expression in decitabine-induced γδ Tregs was negligible (<3%) while 15.5% common γδ Tregs lost foxp3 expression. To confirm the results in vitro we tested the functional ability to prevent GVHD in vivo. GVHD was induced in NOD/SCID mice following busulfan and anti-CD122 condition and 1×107 PBMCs transfusion. Animals were co-injected with either decitabine-induced γδ Tregs or common γδ Tregs at a ratio of 1:1. Survival time and GVHD manifestations of the transplanted mice were evaluated. As a result, transplantation of human PBMCs alone induced lethal GVHD with average survival time 25± 8 days while the survival time was 43± 5 days and 58±7 days in mice co-injected with common γδ Tregs and decitabine-induced γδ Tregs, respectively (p<0.05). Clinical manifestations such as hunched back, diarrhea, and body weight loss were statistically different among 3 groups. To investigate the infiltration of human lymphocytes into nonlymphoid tissues in GVHD mice, we performed immunohistochemical analysis of the liver and intestines using anti-human CD45. Remarkably abundant invasion of human CD45+ cells was observed around the veins in the liver and intestines transplanted with PBMCs alone while less invasion in mice co-injected with common γδ Tregs and the lest invasion in mice co-injected with decitabine-induced γδ Tregs. Altogether, our findings reveal that decitabine and the cytokines can efficiently syngenerize to induce γδ Tregs with enhanced immunosuppression on GVHD which are via higher levels of IL-10 production due to ICOS up-regulation as well as stability of Foxp3 expression. Thus γδ Tregs may be potentially exploited therapeutically in a variety of transplantation settings. Disclosures: No relevant conflicts of interest to declare.

Sorafenib, but not sunitinib, affects function of dendritic cells and induction of primary immune responses

Blood ◽  
2008 ◽  
Vol 111 (12) ◽  
pp. 5610-5620 ◽  
Author(s):  
Madeleine M. Hipp ◽  
Norbert Hilf ◽  
Steffen Walter ◽  
Daniela Werth ◽  
Katharina M. Brauer ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
Immune Responses ◽  
Map Kinases ◽  
Kinase Inhibitors ◽  
Mononuclear Cells ◽  
Cytotoxic T Cell ◽  
Peripheral Blood Mononuclear

AbstractThe tyrosine kinase inhibitors sorafenib and sunitinib are approved for the treatment of patients with malignant diseases. To analyze the possible use of these compounds in combination with immunotherapeutic approaches, we analyzed the effects of both inhibitors on the immunostimulatory capacity of human dendritic cells (DCs) and the induction of primary immune responses in vivo. Sorafenib, but not sunitinib, inhibits function of DCs, characterized by reduced secretion of cytokines and expression of CD1a, major histocompatibility complex, and costimulatory molecules in response to TLR ligands as well as by their impaired ability to migrate and stimulate T-cell responses. These inhibitory effects are mediated by inhibition of PI3 and MAP kinases and NFκB signaling. In contrast, sorafenib had no influence on the phenotype and proliferation of T cells. To analyze the effects of both TKIs on cytotoxic T-cell induction in vivo, C57BL/6 mice were pretreated with sorafenib or sunitinib and immunized with OVA257-264 peptide. Sorafenib, but not sunitinib, application significantly reduced the induction of antigen-specific T cells. Numbers of regulatory T cells were reduced in peripheral blood mononuclear cells from mice treated with sunitinib. These results indicate that sunitinib, but not sorafenib, is suitable for combination with immunotherapeutic approaches for treatment of cancer patients.

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