0000000000350299
AUTHOR
Ingrid Tubbe
A trifunctional dextran-based nanovaccine targets and activates murine dendritic cells, and induces potent cellular and humoral immune responses in vivo.
Dendritic cells (DCs) constitute an attractive target for specific delivery of nanovaccines for immunotherapeutic applications. Here we tested nano-sized dextran (DEX) particles to serve as a DC-addressing nanocarrier platform. Non-functionalized DEX particles had no immunomodulatory effect on bone marrow (BM)-derived murine DCs in vitro. However, when adsorbed with ovalbumine (OVA), DEX particles were efficiently engulfed by BM-DCs in a mannose receptor-dependent manner. A DEX-based nanovaccine containing OVA and lipopolysaccharide (LPS) as a DC stimulus induced strong OVA peptide-specific CD4(+) and CD8(+) T cell proliferation both in vitro and upon systemic application in mice, as well a…
Isolation and subsequent analysis of murine lamina propria mononuclear cells from colonic tissue
Studies on colonic cells in the lamina propria (LP) of mice are important for understanding the cellular and immune responses in the gut, especially in inflammatory bowel diseases (such as morbus crohn and colitis ulcerosa). This protocol details a method to isolate LP cells and characterize freshly isolated cells by quality control experiments to obtain cells that can be used for further investigations. After different steps of digestion of the tissue using collagenase, DNase and dispase, the resulting cells are purified using Percoll gradient. The success of the isolation can be analyzed by cell viability test (Trypan Blue exclusion test) and by flow cytometric analysis to assess apoptosi…
Perforin deficiency attenuates inflammation and tumor growth in colitis-associated cancer
Background: Patients with inflammatory bowel disease (IBD) have a markedly increased risk to develop colon cancer, but there are only limited data about the host antitumor response in such colitis-associated cancer. In the present study we aimed at assessing the role of perforin-dependent effector mechanisms in the immune response in a murine model of colitis-associated colon cancer. Methods: Wildtype and perforin-deficient mice were analyzed in a mouse model of colitis-associated colon cancer using azoxymethane (AOM) and dextran sodium sulfate (DSS). Results: Tumors of wildtype mice showed infiltration of CD4+, CD8+ T cells, natural killer (NK) cells, high numbers of apoptotic cells, and e…
Protection from lethal septic peritonitis by neutralizing the biological function of interleukin 27
The immune response to bacterial infections must be tightly controlled to guarantee pathogen elimination while preventing tissue damage by uncontrolled inflammation. Here, we demonstrate a key role of interleukin (IL)-27 in regulating this critical balance. IL-27 was rapidly induced during murine experimental peritonitis induced by cecal ligation and puncture (CLP). Furthermore, mice deficient for the EBI3 subunit of IL-27 were resistant to CLP-induced septic peritonitis as compared with wild-type controls, and this effect could be suppressed by injection of recombinant single-chain IL-27. EBI3−/− mice displayed significantly enhanced neutrophil migration and oxidative burst capacity during…
EBV-Induced Gene 3 Transcription Is Induced by TLR Signaling in Primary Dendritic Cells via NF-κB Activation
Abstract The EBV-induced gene 3 (EBI3) is expressed in dendritic cells (DCs) and part of the cytokine IL-27 that controls Th cell development. However, its regulated expression in DCs is poorly understood. In the present study we demonstrate that EBI3 is expressed in splenic CD8−, CD8+, and plasmacytoid DC subsets and is induced upon TLR signaling. Cloning and functional analysis of the EBI3 promoter using in vivo footprinting and mutagenesis showed that stimulation via TLR2, TLR4, and TLR9 transactivated the promoter in primary DCs via NF-κB and Ets binding sites at −90 and −73 bp upstream of the transcriptional start site, respectively. Furthermore, we observed that NF-κB p50/p65 and PU.1…
Density of conjugated antibody determines the extent of Fc receptor dependent capture of nanoparticles by liver sinusoidal endothelial cells
Despite considerable progress in the design of multifunctionalized nanoparticles (NPs) that selectively target specific cell types, their systemic application often results in unwanted liver accumulation. The exact mechanisms for this general observation are still unclear. Here we asked whether the number of cell-targeting antibodies per NP determines the extent of NP liver accumulation and also addressed the mechanisms by which antibody-coated NPs are retained in the liver. We used polysarcosine-based peptobrushes (PBs), which in an unmodified form remain in the circulation for >24 h due to the absence of a protein corona formation and low unspecific cell binding, and conjugated them with …
Vaccination with trifunctional nanoparticles that address CD8+ dendritic cells inhibits growth of established melanoma
Aim: We wanted to assess the potency of a trifunctional nanoparticle (NP) that targeted and activated CD8+ dendritic cells (DC) and delivered an antigen to induce antitumor responses. Materials & methods: The DC targeting and activating properties of ferrous NPs conjugated with immunostimulatory CpG-oligonucleotides, anti-DEC205 antibody and ovalbumin (OVA) as a model antigen to induce antigen-specific T-cell responses and antitumor responses were analyzed. Results: OVA-loaded NP conjugated with immunostimulatory CpG-oligonucleotides and anti-DEC205 antibody efficiently targeted and activated CD8+ DC in vivo, and induced strong OVA-specific T-cell activation. Vaccination of B16/OVA tum…
Transforming growth factor induced FoxP3+ regulatory T cells suppress Th1 mediated experimental colitis
Background and aims: The imbalance between effector and regulatory T cells plays a central role in the pathogenesis of inflammatory bowel diseases. In addition to the thymus, CD4+CD25+ regulatory T cells can be induced in the periphery from a population of CD25− T cells by treatment with transforming growth factor β (TGF-β). Here, we analysed the in vivo function of TGF-β induced regulatory T (Ti-Treg) cells in experimental colitis. Methods: Ti-Treg cells were generated in cell culture in the presence or absence of TGF-β and tested for their regulatory potential in experimental colitis using the CD4+CD62L+ T cell transfer model. Results: Ti-Treg cells significantly suppressed Th1 mediated c…
Selective Uptake of Cylindrical Poly(2-Oxazoline) Brush-AntiDEC205 Antibody-OVA Antigen Conjugates into DEC-Positive Dendritic Cells and Subsequent T-Cell Activation
To achieve specific cell targeting by various receptors for oligosaccharides or antibodies, a carrier must not be taken up by any of the very many different cells and needs functional groups prone to clean conjugation chemistry to derive well-defined structures with a high biological specificity. A polymeric nanocarrier is presented that consists of a cylindrical brush polymer with poly-2-oxazoline side chains carrying an azide functional group on each of the many side chain ends. After click conjugation of dye and an anti-DEC205 antibody to the periphery of the cylindrical brush polymer, antibody-mediated specific binding and uptake into DEC205(+) -positive mouse bone marrow-derived dendri…