Search results for "Antigen-presenting cell"
showing 10 items of 279 documents
Rational Combination of Parvovirus H1 With CTLA-4 and PD-1 Checkpoint Inhibitors Dampens the Tumor Induced Immune Silencing
2019
The recent therapeutic success of immune checkpoint inhibitors in the treatment of advanced melanoma highlights the potential of cancer immunotherapy. Oncolytic virus-based therapies may further improve the outcome of these cancer patients. A human ex vivo melanoma model was used to investigate the oncolytic parvovirus H-1 (H-1PV) in combination with ipilimumab and/or nivolumab. The effect of this combination on activation of human T lymphocytes was demonstrated. Expression of CTLA-4, PD-1, and PD-L1 immune checkpoint proteins was upregulated in H-1PV-infected melanoma cells. Nevertheless, maturation of antigen presenting cells such as dendritic cells was triggered by H-1PV infected melanom…
Cancer Acidity and Hypertonicity Contribute to Dysfunction of Tumor-Associated Dendritic Cells: Potential Impact on Antigen Cross-Presentation Machin…
2020
Macrophages (M) and dendritic cells (DC), major players of the mononuclear phagocyte system (MoPh), are potent antigen presenting cells that steadily sense and respond to signals from the surrounding microenvironment, leading to either immunogenic or tolerogenic outcomes. Next to classical MHC-I/MHC-II antigen-presentation pathways described in the vast majority of cell types, a subset of MoPh (CD8+, XCR1+, CLEC9A+, BDCA3+ conventional DCs in human) is endowed with a high competence to cross-present external (engulfed) antigens on MHC-I molecules to CD8+ T-cells. This exceptional DC function is thought to be a crucial crossroad in cytotoxic antitumor immunity and has been extensively studie…
Mast cells within cellular networks
2018
Mast cells are highly versatile in terms of their mode of activation by a host of stimuli and their ability to flexibly release a plethora of biologically highly active mediators. Within the immune system, mast cells can best be designated as an active nexus interlinking innate and adaptive immunity. Here we try to draw an arc from initiation of acute inflammatory reactions to microbial pathogens to development of adaptive immunity and allergies. This multifaceted nature of mast cells is made possible by interaction with multiple cell types of immunologic and nonimmunologic origin. Examples for the former include neutrophils, eosinophils, T cells, and professional antigen-presenting cells. …
Treg cells as potential cellular targets for functionalized nanoparticles in cancer therapy.
2016
Treg cell-mediated immune suppression appears to represent a significant barrier to effective anticancer immune responses and their inactivation or removal is viewed as a potential therapeutic approach. Although suitable tools for selective Treg cell manipulation in man are missing, their number and function can be altered by a number of drugs and biologicals and by reprogramming tumor-infiltrating antigen presenting cells. Nanoparticles offer exceptional new options in drug and gene delivery by prolonging the circulation time of their cargo, protecting it from degradation and promoting its local accumulation in cells and tissues. In tumor therapy, the use of nanoparticles is expected to o…
Gatekeeper role of brain antigen‐presenting CD11c + cells in neuroinflammation
2015
Multiple sclerosis is the most frequent chronic inflammatory disease of the CNS. The entry and survival of pathogenic T cells in the CNS are crucial for the initiation and persistence of autoimmune neuroinflammation. In this respect, contradictory evidence exists on the role of the most potent type of antigen-presenting cells, dendritic cells. Applying intravital two-photon microscopy, we demonstrate the gatekeeper function of CNS professional antigen-presenting CD11c(+) cells, which preferentially interact with Th17 cells. IL-17 expression correlates with expression of GM-CSF by T cells and with accumulation of CNS CD11c(+) cells. These CD11c(+) cells are organized in perivascular clusters…
NKG2D stimulation of CD8(+) T cells during priming promotes their capacity to produce cytokines in response to viral infection in mice
2017
NKG2D is an activating receptor that is expressed on most cytotoxic cells of the immune system, including NK cells, γδ and CD8+ T cells. It is still a matter of debate whether and how NKG2D mediates priming of CD8+ T cells in vivo, due to a lack of studies where NKG2D is eliminated exclusively in these cells. Here we studied the impact of NKG2D on effector CD8+ T-cell formation. NKG2D-deficiency that is restricted to murine CD8+ T cells did not impair antigen-specific T-cell expansion following mCMV and LCMV infection, but reduced their capacity to produce cytokines. Upon infection, conventional dendritic cells induce NKG2D ligands, which drive cytokine production on CD8+ T cells via the Da…
Plasma phospholipid transfer protein (PLTP) modulates adaptive immune functions through alternation of T helper cell polarization
2016
International audience; Objective: Plasma phospholipid transfer protein (PLTP) is a key determinant of lipoprotein metabolism, and both animal and human studies converge to indicate that PLTP promotes atherogenesis and its thromboembolic complications. Moreover, it has recently been reported that PLTP modulates inflammation and immune responses. Although earlier studies from our group demonstrated that PLTP can modify macrophage activation, the implication of PLTP in the modulation of T-cell-mediated immune responses has never been investigated and was therefore addressed in the present study. Approach and results: In the present study, we demonstrated that PLTP deficiency in mice has a pro…
Myeloid cells do not contribute to gender-dependent differences in disease outcome in murine cutaneous leishmaniasis.
2015
Gender-associated differences in the outcome of infections are well known. Apart from behavior-released differences in their incidence, immunological factors also contribute to disease outcome. The underlying mechanisms are often unknown. Here, we show that in murine experimental leishmaniasis, female mice develop larger skin lesions that harbor significantly more parasites, exhibit increased parasite dissemination to visceral organs associated with a shift towards T helper (Th) 2 immunity with increased levels of IL-4. Antigen presenting cells (APC) responsible for T cell priming, such as macrophages or dendritic cells, were not involved in the process. Additionally, in adoptive transfer e…
Exome-wide somatic mutation characterization of small bowel adenocarcinoma
2018
Small bowel adenocarcinoma (SBA) is an aggressive disease with limited treatment options. Despite previous studies, its molecular genetic background has remained somewhat elusive. To comprehensively characterize the mutational landscape of this tumor type, and to identify possible targets of treatment, we conducted the first large exome sequencing study on a population-based set of SBA samples from all three small bowel segments. Archival tissue from 106 primary tumors with appropriate clinical information were available for exome sequencing from a patient series consisting of a majority of confirmed SBA cases diagnosed in Finland between the years 2003–2011. Paired-end exome sequencing was…
Peptide Processing Is Critical for T-Cell Memory Inflation and May Be Optimized to Improve Immune Protection by CMV-Based Vaccine Vectors.
2016
Cytomegalovirus (CMV) elicits long-term T-cell immunity of unparalleled strength, which has allowed the development of highly protective CMV-based vaccine vectors. Counterintuitively, experimental vaccines encoding a single MHC-I restricted epitope offered better immune protection than those expressing entire proteins, including the same epitope. To clarify this conundrum, we generated recombinant murine CMVs (MCMVs) encoding well-characterized MHC-I epitopes at different positions within viral genes and observed strong immune responses and protection against viruses and tumor growth when the epitopes were expressed at the protein C-terminus. We used the M45-encoded conventional epitope HGI…