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 ◽  
...  

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

Blood ◽  
1988 ◽  
Vol 72 (3) ◽  
pp. 956-963
Author(s):  
GC Barbano ◽  
A Schenone ◽  
S Roncella ◽  
R Ghio ◽  
A Corcione ◽  
...  

Abstract Human peripheral blood mononuclear cells (PBMC) were stimulated in vitro with anti-lymphocyte globulin (ALG), and the phenotypic and functional properties of the blasts obtained were investigated. When stained with monoclonal antibodies (MoAbs), all of the blasts were identified as T cells that expressed predominantly the CD4 phenotype (70% of the cells). The remaining blasts were CD8+. These findings demonstrate that ALG stimulates both helper-inducer and cytotoxic- suppressor cells at random since the CD4 to CD8 ratio in the stimulated blasts was the same as in resting PBMC. This ratio is different from that observed in short-term cultures of T cells stimulated with phytohemagglutinin (PHA) under the same conditions (CD4 to CD8 ratio less than 1). ALG-stimulated T cells were cloned by limiting dilution in the presence of recombinant Interleukin-2 (rIL-2). The clones obtained were expanded and maintained in long term cultures with rIL-2. Thirty-two clones were tested for their capacity of producing colony stimulating activity (CSA) or burst promoting activity (BPA). Twenty- eight of them produced CSA and 12 produced BPA. No correlation was found between the surface phenotype and the ability of the clones to produce CSA or BPA (ie, both the CD4+ and CD8+ clones released the cytokines). When 16 of the same clones were tested for II-2 and gamma interferon (gamma IFN) production, 12 were found to be gamma INF and IL- 2 producers. All of the gamma IFN producers also released IL-2, whereas in the single clones no correlation was found with the capacity of releasing BPA and CSA. Supernatants from selected T-cell clones were also tested for hematopoietic growth factor activities in the presence of neutralizing antisera to human granulocyte-macrophage colony stimulating factor (GM-CSF) or to Interleukin-3 (IL-3). It was found that most CSA was attributable to GM-CSF, whereas BPA was mainly related to the presence of IL-3.


Biology ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 211 ◽  
Author(s):  
Nour Z. Atwany ◽  
Seyedeh-Khadijeh Hashemi ◽  
Manju Nidagodu Jayakumar ◽  
Mitzi Nagarkatti ◽  
Prakash Nagarkatti ◽  
...  

Regulatory T cells (Tregs) are key players in the regulation of inflammatory responses. In this study, two natural molecules, namely, sparteine sulfate (SS) and harpagoside (Harp), were investigated for their ability to induce Tregs in human peripheral blood mononuclear cells (PBMCs). PBMCs were isolated from healthy volunteers and grown in the presence or absence of ConA, with TGF-beta, SS or Harp. Expression of the mRNA of FoxP3, TGF-beta, IL-10 and GAPDH was assessed via q-PCR. The expression of Treg markers including CD4, CD25, CD127 and FoxP3 was measured via flow cytometry. The secretion of IL-10 and TGF-beta by cultured cells was assessed by ELISA. Furthermore, the suppressive role of SS and Harp on PBMCs in vitro was tested via allogeneic mixed lymphocyte reaction (MLR). Data obtained show that both compounds increased the expression of FoxP3, TGF-beta and IL-10 mRNA in resting PBMCs but to a lesser extent in activated cells. Moreover, they significantly increased the percent of CD4+CD25+FoxP3+CD127− Tregs in activated and naïve PBMCs. Functionally, both compounds caused a significant reduction in the stimulation index in allogeneic MLR. Together, our data demonstrate for the first time that SS and Harp can induce human Tregs in vitro and therefore have great potential as anti-inflammatory agents.


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

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.


2005 ◽  
Vol 79 (23) ◽  
pp. 14526-14535 ◽  
Author(s):  
Carlos F. Narváez ◽  
Juana Angel ◽  
Manuel A. Franco

ABSTRACT We have previously shown that very few rotavirus (RV)-specific T cells that secrete gamma interferon circulate in recently infected and seropositive adults and children. Here, we have studied the interaction of RV with myeloid immature (IDC) and mature dendritic cells (MDC) in vitro. RV did not induce cell death of IDC or MDC and induced maturation of between 12 and 48% of IDC. Nonetheless, RV did not inhibit the maturation of IDC or change the expression of maturation markers on MDC. After treatment with RV, few IDC expressed the nonstructural viral protein NSP4. In contrast, a discrete productive viral infection was shown in MDC of a subset of volunteers, and between 3 and 46% of these cells expressed NSP4. RV-treated IDC secreted interleukin 6 (IL-6) (but not IL-1β, IL-8, IL-10, IL-12, tumor necrosis factor alpha, or transforming growth factor beta), and MDC released IL-6 and small amounts of IL-10 and IL-12p70. The patterns of cytokines secreted by T cells stimulated by staphylococcal enterotoxin B presented by MDC infected with RV or uninfected were comparable. The frequencies and patterns of cytokines secreted by memory RV-specific T cells evidenced after stimulation of peripheral blood mononuclear cells (PBMC) with RV were similar to those evidenced after stimulation of PBMC with RV-infected MDC. Finally, IDC treated with RV strongly stimulated naive allogeneic CD4+ T cells to secrete Th1 cytokines. Thus, although RV does not seem to be a strong maturing stimulus for DC, it promotes their capacity to prime Th1 cells.


Author(s):  
Yi Zhong ◽  
Ting-Ting Lu ◽  
Xiao-Mei Liu ◽  
Bing-Li Liu ◽  
Yun Hu ◽  
...  

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.


Blood ◽  
2008 ◽  
Vol 111 (7) ◽  
pp. 3675-3683 ◽  
Author(s):  
Xingmin Feng ◽  
Sachiko Kajigaya ◽  
Elena E. Solomou ◽  
Keyvan Keyvanfar ◽  
Xiuli Xu ◽  
...  

Abstract Regulatory T cells (Treg) play important roles in suppressing immune responses and maintaining tolerance. Rabbit antithymocyte globulin (rATG) and horse ATG (hATG) are widely used in the treatment of immune-mediated syndromes, but their effects on Treg are unknown. We show here that in vitro culture of normal human peripheral blood mononuclear cells (PBMCs) with a low-dose rATG resulted in marked expansion of functional Treg by converting CD4+CD25− T cells to CD4+CD25+ T cells. hATG did not expand but rather decreased Treg. Immuno-blot showed increased expression of FOXP3 and NFAT1 in CD4+CD25− and CD4+CD25+ T cells exposed to rATG. PBMCs treated with rATG displayed increased interleukin-10 in culture supernatants than those treated with hATG. Furthermore, rATG and hATG showed differences in their potential to stimulate CD4+ T cells as examined using different activation markers. Microarray revealed that rATG induced markedly different gene-expression patterns in PBMCs, compared with hATG-treated or untreated PBMCs. Our findings indicate that rATG expanded Treg, probably through transcriptional regulation by enhanced NFAT1 expression, in turn conferring CD4+CD25− T cell FOXP3 expression and regulatory activity. The therapeutic effects of rATG may occur not only because of lymphocyte depletion but also enhanced Treg cell number and function.


2012 ◽  
Vol 56 (8) ◽  
pp. 4381-4390 ◽  
Author(s):  
Martha Stefanidou ◽  
Carolina Herrera ◽  
Naomi Armanasco ◽  
Robin J. Shattock

ABSTRACTThe maturation of newly formed human immunodeficiency virus type 1 (HIV-1) virions is a critical step for the establishment of productive infection. We investigated the potential of saquinavir (SQV), a protease inhibitor (PI) used in highly active antiretroviral therapy (HAART), as a candidate microbicide. SQV inhibited replication of clade B and clade C isolates in a dose-dependent manner in all cellular models tested: PM-1 CD4 T cells, peripheral blood mononuclear cells (PBMCs), monocyte-derived macrophages (MDMs), and immature monocyte-derived dendritic cells (iMDDCs). SQV also inhibited production of infectious virus in cervical, penile, and colorectal explants cocultured with T cells. Moreover, SQV demonstrated inhibitory potency againsttransinfection of T cells byin vitro-derived dendritic cells and by primary dendritic cells that emigrate from penile and cervical tissue explants. No cellular or tissue toxicity was detected in the presence of SQV, suggesting that this drug could be considered for development as a component of an effective microbicide, capable of blocking viral maturation and transmission of HIV-1 at mucosal surfaces.


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