Search results for "Dendritic Cell"

LFA-1 Contributes to Signal I of T-Cell Activation and to the Production of Th1 Cytokines

2010

The beta(2) integrins are important for both transendothelial migration of leukocytes and T-cell activation during antigen presentation. In T cells, triggering of leukocyte functional antigen-1 (LFA-1) is required for full activation and T-helper (Th)1/Th2 differentiation. We used CD18-deficient (CD18(-/-)) mice to examine the role of LFA-1 in the activation of T cells. Compared with wild-type controls, CD18(-/-) T cells proliferated normally when stimulated with antibodies against CD3 and CD28, but secreted significantly less IFN-gamma and IL-2 than their wild-type counterparts. However, when T cells were stimulated with dendritic cells (DCs) that provide additional LFA-1 ligation, the pro…

Activation of phenotypically heterogeneous murine T cell receptor gamma delta + dendritic epidermal T cells by self-antigen(s).

1995

Adult murine epidermis contains a population of Thy-1+, CD45+, CD3+, CD4- and CD8- in situ primarily T cell receptor (TCR) V gamma 3+/V delta 1+ dendritic epidermal T cells (DETC). In the present study, cell surface phenotypes as well as functional properties of DETC were characterized by using in vitro mitogen-stimulated short-term- (10 days) and cloned long-term-cultured (1 year) DETC lines. Phenotypic characterization revealed that80% of the short-term-cultured cells were routinely TCR gamma delta +, CD4-, CD8-. The majority expressed the V gamma 3 TCR. Seventy-five percent of the lines contained detectable numbers of V gamma 2+ (5-7%) and V gamma 2-3- cells (2-3%). Four different types …

Delivering all in one: Antigen-nanocapsule loaded with dual adjuvant yields superadditive effects by DC-directed T cell stimulation

2018

Therapeutic vaccination is and remains a major challenge, particularly in cancer treatment. In this process, the effective activation of dendritic cells by a combination of distinctly acting adjuvants and an antigen is crucial for success. While most common vaccine formulations lack the efficiency to trigger sufficient T cell responses in a therapeutic tumor treatment, nanovaccines offer unique properties to tackle that challenge. Here, we report the stepwise development of a nanocapsule for vaccination approaches, comprising a shell consisting of antigen and loaded with a superadditive adjuvant combination. In a first initial step, we identified the combination of resiquimod (R848) and mur…

Cutaneous leishmaniasis: Distinct functions of dendritic cells and macrophages in the interaction of the host immune system with Leishmania major

2017

Leishmaniasis is transmitted by sand flies leading to parasite inoculation into skin. In the mammalian host, the parasite primarily resides in skin macrophages (MΦ) and dendritic cells (DC). MΦ are silently invaded by the parasite eliciting a stress response, whereas DC become activated, release IL-12, and prime antigen-specific T cells. Here we review the basics of the immune response against this human pathogen and elucidate the role and function DC and MΦ for establishment of protective immunity against leishmaniasis. We focus on cell type-specific differences in parasite uptake, phagocyte activation and processing of parasite antigens to facilitate an understanding how their respective …

Opposing functions of thymic stromal lymphopoietin–responsive basophils and dendritic cells in a mouse model of atopic dermatitis

2015

A Synthetic MUC1 Anticancer Vaccine Containing Mannose Ligands for Targeting Macrophages and Dendritic Cells

2017

A MUC1 anticancer vaccine equipped with covalently linked divalent mannose ligands was found to improve the antigen uptake and presentation by targeting mannose-receptor-positive macrophages and dendritic cells. It induced much stronger specific IgG immune responses in mice than the non-mannosylated reference vaccine. Mannose coupling also led to increased numbers of macrophages, dendritic cells, and CD4+ T cells in the local lymph organs. Comparison of di- and tetravalent mannose ligands revealed an increased binding of the tetravalent version, suggesting that higher valency improves binding to the mannose receptor. The mannose-coupled vaccine and the non-mannosylated reference vaccine ind…

Allergological implication of the quaternary hexameric structure of the cockroach allergen Per a 3.

2007

Summary Background Cockroach allergens play a very important role in allergic diseases, especially asthma. The major allergen of the American cockroach (Periplaneta americana), Per a 3, naturally occurs as isoforms of hexamers. Objective The aim of this study was to investigate whether the hexameric structures of Per a 3 influence their allergenicity and immunogenicity. Methods Therefore, we compared the different effects of native hexamers and dissociated monomers of cockroach haemolymph (HL), containing almost only Per a 3 proteins (HL-Per a 3), on proliferation and T-helper type 1 (Th1)/Th2 cytokine production of human CD4+ T cells in co-culture with allergen-pulsed monocyte-derived auto…

The gp130-stimulating designer cytokine hyper-IL-6 promotes the expansion of human hematopoietic progenitor cells capable to differentiate into funct…

2000

Abstract Objective . Hyper-IL-6, a fusion protein of interleukin-6 and its specific receptor, together with stem cell factor leads to the proliferation of primitive hematopoietic progenitor cells. Based on these findings, the current study examined whether hyper-IL-6 promotes the growth of precursor cells that can be further differentiated into dendritic cells in the presence of additional cytokines. Methods . Dendritic cell cultures were generated from CD34 + hematopoietic progenitor cells derived either from bone marrow or from peripheral blood. CD34 + cells were cultured in the presence of cytokines for 2 weeks and then used for phenotyping and T-cell stimulation assays. Results . Hyper-…

A comparison of two types of dendritic cell as adjuvants for the induction of melanoma-specific T-cell responses in humans following intranodal injec…

2001

Dendritic cells (DCs) elicit potent anti-tumoral T-cell responses in vitro and in vivo. However, different types of DC have yet to be compared for their capacity to induce anti-tumor responses in vivo at different developmental stages. Herein, we correlated the efficiencies of different types of monocyte-derived DC as vaccines on the resulting anti-tumor immune responses in vivo. Immature and mature DCs were separately pulsed with a peptide derived from tyrosinase, MelanA/MART-1 or MAGE-1 and a recall antigen. Both DC populations were injected every 2 weeks in different lymph nodes of the same patient. Immune responses were monitored before, during and after vaccination. Mature DCs induced …

Modulation of dendritic cell properties by laquinimod as a mechanism for modulating multiple sclerosis.

2013

Laquinimod is an orally administered compound that is under investigation in relapsing-remitting multiple sclerosis. To understand the mechanism by which laquinimod exerts its clinical effects, we have performed human and murine studies assessing its immunomodulatory properties. In experimental autoimmune encephalomyelitis, the therapeutic administration of laquinimod beginning during the recovery of SJL mice, prevented further relapses as expected and strongly reduced infiltration of CD4+ and CD8+ T cells in the central nervous system. We hypothesized that this beneficial effect was mediated by dendritic cells, since we and others found a modulation of different dendritic cell subsets unde…