This article is part of the Dendritic Cell Guidelines article series, which provides a collection of state-of-the-art protocols for the preparation, phenotype analysis by flow cytometry, generation, fluorescence microscopy and functional characterization of mouse and human dendritic cells (DC) from lymphoid organs and various nonlymphoid tissues. DC are sentinels of the immune system present in almost every mammalian organ. Since they represent a rare cell population, DC need to be extracted from organs with protocols that are specifically developed for each tissue.
View Article and Find Full Text PDFHuman skin is a preferred vaccination site as it harbors multiple dendritic cell (DC) subsets, which display distinct C-type lectin receptors (CLR) that recognize pathogens. Antigens can be delivered to CLR by antibodies or ligands to boost antigen-specific immune responses. This concept has been established in mouse models but detailed insights into the functional consequences of antigen delivery to human skin DC in situ are sparse.
View Article and Find Full Text PDFBackground: Immunotherapy with checkpoint inhibitors has shown impressive results in patients with melanoma, but still many do not benefit from this line of treatment. A lack of tumor-infiltrating T cells is a common reason for therapy failure but also a loss of intratumoral dendritic cells (DCs) has been described.
Methods: We used the transgenic tg(Grm1)EPv melanoma mouse strain that develops spontaneous, slow-growing tumors to perform immunological analysis during tumor progression.
Genetic activation of hedgehog/glioma-associated oncogene homolog (HH/GLI) signaling causes basal cell carcinoma (BCC), a very frequent nonmelanoma skin cancer. Small molecule targeting of the essential HH effector Smoothened (SMO) has proven an effective therapy of BCC, though the frequent development of drug resistance poses major challenges to anti-HH treatments. In light of recent breakthroughs in cancer immunotherapy, we analyzed the possible immunosuppressive mechanisms in HH/GLI-induced BCC in detail.
View Article and Find Full Text PDFTherapeutic success of targeted therapy with BRAF inhibitors (BRAFi) for melanoma is limited by resistance development. Observations from preclinical mouse models and recent insights into the immunological effects caused by BRAFi give promise for future development of combination therapy for human melanoma. In our study, we used the transplantable D4M melanoma mouse model with the BRAF mutation and concomitant PTEN loss in order to characterize alterations in tumor-infiltrating effector immune cells when tumors become resistant to BRAFi.
View Article and Find Full Text PDFTissue immunosurveillance is an important mechanism to prevent cancer. Skin treatment with the carcinogen 7,12-dimethylbenz(a)anthracene (DMBA), followed by the tumor promoter 12-O-tetra-decanoyl-phorbol-13-acetate (TPA), is an established murine model for squamous cell carcinoma (SCC). However, the innate immunological events occurring during the initiation of chemical carcinogenesis with DMBA remain elusive.
View Article and Find Full Text PDFSkin dendritic cells (DC) are strategically positioned at the body's second largest epithelial border to the environment. Hence they are the first antigen presenting cells that encounter invading pathogens and environmental antigens, including contact sensitizers and carcinogens penetrating the skin. Moreover, DC have the unique ability to induce immunity or tolerance and thus take center stage in regulating innate and adaptive immune responses.
View Article and Find Full Text PDFMurine tumor models that closely reflect human diseases are important tools to investigate carcinogenesis and tumor immunity. The transgenic (tg) mouse strain tg(Grm1)EPv develops spontaneous melanoma due to ectopic overexpression of the metabotropic glutamate receptor 1 (Grm1) in melanocytes. In the present study, we characterized the immune status and functional properties of immune cells in tumor-bearing mice.
View Article and Find Full Text PDFSkin is in daily contact with potentially harmful molecules from the environment such as cigarette smoke, automobile emissions, industrial soot and groundwater. Pregnane X receptor (PXR) is a transcription factor expressed in liver and intestine that is activated by xenobiotic chemicals including drugs and environmental pollutants. Topical application of the tumor initiator 7,12-dimethylbenz(a)anthracene (DMBA) enhances Pxr, Cyp1a1, Cyp1b1 and Cyp3a11, but not Ahr expression in the skin.
View Article and Find Full Text PDFCYTIP (cytohesin interacting protein) is an intracellular molecule induced in dendritic cells during maturation. CYTIP modulates the binding intensity of the adhesion molecule LFA-1. If dendritic cells are silenced for CYTIP they keep longer contacts with T-cells resulting in a lower T cell stimulation.
View Article and Find Full Text PDFCytohesin-interacting protein (Cytip) is induced during dendritic cell (DC) maturation and in T cells upon activation. It has also been shown to be involved in the regulation of immune responses. Here, we evaluated the functional consequences of Cytip deficiency in DCs using Cytip knockout (KO) mice.
View Article and Find Full Text PDFLangerhans cells (LC) are a subset of skin-resident dendritic cells (DC) that reside in the epidermis as immature DC, where they acquire Ag. A key step in the life cycle of LC is their activation into mature DC in response to various stimuli, including epicutaneous sensitization with hapten and skin infection with Candida albicans. Mature LC migrate to the skin-draining LN, where they present Ag to CD4 T cells and modulate the adaptive immune response.
View Article and Find Full Text PDFThe B lymphocyte adaptor molecule of 32 kDa (Bam32) is strongly induced during the maturation of dendritic cells (DC). Most known functions of Bam32 are related to the signaling of the B cell receptor for Ag. Because DC do not express receptors specific for Ags, we aim at characterizing the role of Bam32 in human monocyte-derived DC in this study.
View Article and Find Full Text PDFSkin-resident dendritic cells (DCs) are well positioned to encounter cutaneous pathogens and are required for the initiation of adaptive immune responses. There are at least three subsets of skin DC- Langerhans cells (LC), Langerin(+) dermal DCs (dDCs), and classic dDCs. Whether these subsets have distinct or redundant function in vivo is poorly understood.
View Article and Find Full Text PDFOver the last decade several groups, including ourself, have published a series of findings on a molecule expressed in leukocytes. The molecule was termed Cybr, CYTIP or CASP for its functions and PSCDBP for its binding properties. In this review we attempt to chronicle and combine the findings on the molecule to gain an overview of its features.
View Article and Find Full Text PDF